2017 NEC Significant Code Changes Part 3

Transcription

1 2017 NEC Significant Code Changes Part 3 Eight (8) Continuing Education Hours Wisconsin Department of Safety and Professional Services (DSPS) Course Approval #18959 Approved Continuing Education for Wisconsin Trades Professionals 2017 NEC Significant Code Changes Part 3 i

2 2017 Ezekiel Enterprises, LLC Provider# EZ-CE.com Contact Information Mailing Address 301 Mission Dr. Unit 571 New Smyrna Beach, FL Registered Corporate Address 1623 Central Ave. Ste. 201 Cheyenne, WY Administrative & Technical Support Ph: am-5pm EST Mon-Fri 24/7 Instructor Support Ph: am-5pm EST Mon-Fri NEC Significant Code Changes Part 3 ii

3 2017 NEC Significant Code Changes Part 3 LEARNING OBJECTIVES Upon completion of this course the student will be able to: 1. Become familiar with some of the significant changes including additions, deletions, and modification to the 2017 Edition of NFPA 70: National Electrical Code (NEC) from the 2014 Edition 2. Comprehend, after reviewing the significant changes and additions to the 2017 Edition of NFPA 70: National Electrical Code (NEC) the large scope of the changes to the code, thereby seeking additional and more thorough reviews of the entire code, following completion of this course. Introduction Every three years, the National Electrical Code (NEC ) is revised and expanded. Initially the NFPA received 4,012 public suggestions for changes, which resulted in 1,235 first revisions. There were 1,513 public comments submitted in response to these 1,235 first revisions, resulting in 559 second revisions. Changes included editorial clarification, expanded requirements, new requirements, deleted requirements, and the relocation of other requirements. Nine new articles were proposed, and five new articles were added to the 2017 NEC. With the fast pace of technology, it s more important than ever for anyone participating in the electrical industry to get up to speed with all the changes. o o o o o What to Expect In this course the student will be presented an overview of the most significant changes found in the 2017 NEC. Although every effort has been made to the accuracy of the material presented, by no means shall the student use or substitute this material for the official 2017 NEC. This is part 1 of a series of courses covering the changes and will progress through each chapter and its articles presenting the many important changes. Additionally, for added awareness the exact text from the NEC will be presented. It will be highlighted and marked with the following icon NEC Significant Code Changes Part 3 1

4 CHAPTER 6 EQUIPMENT FOR GENERAL USE Article 600 Electric Signs and Outline Lighting New (B) Signs with a Retrofitted Illumination System A new marking requirement was added to 600.4(B) to indicate that the illumination system has been replaced with a listed retrofit kit. This new marking requirement for retrofit kits will clarify that replacement of such things as fluorescent lamps is prohibited after a retrofit kit with tubular LEDs has been installed. This type of retrofit will require additional marking to alert service personnel that the sign has been modified. A reference to (B) will require the label to address the hazard involved with words and/or symbols. It also addresses the location of the required label. These markings must include the kit providers and installer s name, logo, or unique identifier. The installer of the kit needs to be identified since the installation company may not be the manufacturer of the retrofit kit or the original sign. This marking provides the AHJ with a means of identifying the installer of the field conversion Markings. (Electric Signs and Outline Lighting) (B) Signs with a Retrofitted Illumination System. (1) The retrofitted sign shall be marked that the illumination system has been replaced. (2) The marking shall include the kit providers and installer s name, logo, or unique identifier. (3) Signs equipped with tubular light-emitting diode lamps powered by the existing sign sockets shall require an additional warning label include a label alerting the service personnel that the sign has been modified. The label shall meet the requirements of (B). The label shall also include a warning not to install fluorescent lamps and shall also be visible during relamping NEC Significant Code Changes Part 3 2

5 New (A)(1), Ex. No. 2 Disconnects. (Electric Signs and Outline Lighting) A new exception was added to specifically address a sign enclosure or sign body that supplies an internal panelboard(s) in that same sign enclosure or sign body. A field-applied permanent warning label that is visible during servicing is required to be applied to the raceway containing these energized conductors at or near the point of entry into the sign enclosure or sign body complying with (B). The marking on the warning label must include the location of the disconnecting means for the energized conductor(s), with the disconnecting means being capable of being locked in the open position in accordance with Disconnects. Each sign and outline lighting system, feeder circuit conductor(s), or branch circuit(s) supplying a sign, outline lighting system, or skeleton tubing shall be controlled by an externally operable switch or circuit breaker that opens all ungrounded conductors and controls no other load. The switch or circuit breaker shall open all ungrounded conductors simultaneously on multi-wire branch circuits in accordance with 210.4(B). Signs and outline lighting systems located within fountains shall have the disconnect located in accordance with Exception No. 1: A disconnecting means shall not be required for an exit directional sign located within a building. Exception No. 2: A disconnecting means shall not be required for cord-connected signs with an attachment plug. Informational Note: The location of the disconnect is intended to allow service or maintenance personnel complete and local control of the disconnecting means. (A) Location. (1) At Point of Entry to a Sign Enclosure. The disconnect shall be located at the point the feeder circuit or branch circuit(s) supplying a sign or outline lighting system enters a sign enclosure, a sign body, or a pole in accordance with 600.5(C)(3) and. The 2017 NEC Significant Code Changes Part 3 3

6 disconnect shall disconnect open all wiringungrounded conductors where it enters the enclosure of the sign or pole. Exception No. 1: A disconnect shall not be required for branch circuit(s) or feeder circuitsconductor(s) passing through the sign where enclosed in a Chapter 3 listed raceway or metal-jacketed cable identified for the location. Exception No. 2: A disconnect shall not be required at the point of entry to a sign enclosure or sign body for branch circuit(s) or feeder conductor(s) that supply an internal panelboard(s) in a sign enclosure or sign body. The conductors shall be enclosed in a Chapter 3 listed raceway or metal-jacketed cable identified for the location. A field-applied permanent warning label that is visible during servicing shall be applied to the raceway at or near the point of entry into the sign enclosure or sign body. The warning label shall comply with (B) and state the following: Danger. This raceway contains energized conductors. The marking shall include the location of the disconnecting means for the energized conductor(s). The disconnecting means shall be capable of being locked in the open position in accordance with New/Revision Class 2 Sign Illumination Systems, Secondary Wiring. The title of was changed to Class 2 Sign Illumination Systems, Secondary Wiring, and the section was expanded to cover all types of Class 2 systems, not just LED systems. The previous title and content of this section limited the rules for use of Class 2 to LED systems, thus leaving other light sources powered by Class 2 sources outside the scope of the section. Revisions to Article 411 (Lighting Systems Operating at 30 Volts or Less and Lighting Equipment Connected to Class 2 Power Sources) in the 2014 NEC provided the model for the necessary changes to by generically referring to low-voltage lighting and equipment connected to a Class 2 power source without specifying any particular illumination type such an LED lighting system. This same structure has been applied to sign illumination systems at to make it clear that illumination systems other than LED systems with Class 2 circuits are permitted. Additionally, two new tables were added to (A) for the 2017 NEC. Table (A) (1) titled, Applications of Power Limited Cable in Signs and Outline Lighting, details the requirements for Class 2 circuits listed for the application in signs and outline lighting. Table (A)(2) titled, Class 2 Cable Substitutions, provides directions for ascertaining permitted cable substitutions in these sign applications NEC Significant Code Changes Part 3 4

7 LED Class 2 Sign Illumination Systems, Secondary Wiring. The wiring methods and materials used shall be installed in accordance with the sign manufacturer s installation instructions using any applicable wiring methods from Chapter 3, Wiring Methods, and the requirements for Class 2 circuits contained in Part III of Article 725, as applicable (C), , and (A), (B), (C), and (D). (A) Insulation and Sizing of Class 2 Conductors. Listed Class 2 cable listed for the application that complies with Table (A) (1) or Table (A)(2) for substitutions shall be installed on the load side of the Class 2 power source. The conductors shall have an ampacity not less than the load to be supplied and shall not be sized smaller than AWG. Table (A)(1) Applications of Power Limited Cable in Signs and Outline Lighting Table (A)(2) Class 2 Cable Substitutions 2017 NEC Significant Code Changes Part 3 5

8 (1) General Use. CL2 or CL3, PLTC, or any listed applicable cable for general use shall be installed within and on buildings or structures. (2) Other Building Locations. In other locations, any listed applicable cable permitted in (A)(1), (A)(2), (A)(3), and (A)(4) and Table (A)(1) and (A)(2) shall be permitted to be used as follows: (1) CL2P or CL3P Ducts, plenums, or other spaces used for environmental air (2) CL2R or CL3R Vertical shafts and risers (3) Substitutions from Table (A)(2) (3) Wet Locations. Class 2 cable used in a wet location shall be listed and marked identified suitable for use in a wet locations or have a moisture-impervious metal sheath. (4) Other Locations. In other locations, any applicable cable permitted in Table shall be permitted to be used Class 2 cable exposed to sunlight shall be listed and marked sunlight resistant suitable for outdoor use. (B) Installation. Secondary wiring shall be installed in accordance with (B)(1) and (B)(2). (1) Support Wiring shall be installed and supported in a neat and workmanlike manner. Cables and conductors installed exposed on the surface of ceilings and sidewalls shall be supported by the building structure in such a manner that the cable is not be damaged by normal building use. The cable shall be supported and secured at intervals not exceeding 1.8 m (6 ft). Such cables shall be supported by straps, staples, hangers, cable ties, or similar fittings designed and installed so as not to damage the cable. The installation shall also comply with 300.4(D). (2) Connections in cable and conductors shall be made with listed insulating devices and be accessible after installation. Where made in a wall, connections shall be enclosed in a listed box. (C) Protection Against Physical Damage. Where subject to physical damage, the conductors shall be protected and installed in accordance with (D) Grounding and Bonding. Grounding and bonding shall be in accordance with NEC Significant Code Changes Part 3 6

9 New , Photovoltaic (PV) Powered Sign , Photovoltaic (PV Powered) Sign, was added to Article 600 covering field wiring and installation of PV powered signs. PV powered signs listed to UL 48 (Standard for Electric Signs), specifically Section , are to be used in accordance with Code requirements relative to general PV usage in Article 690 and specific rules for PV powered sign installations are covered in UL 48. The rules in are intended to harmonize with Article 600, Article 690, and the end use of PV powered signs constructed in accordance with UL 48. Self-contained, standalone PV powered signs operating at or below Class 2 voltages are considered safe from electrical shock the same as any other Class 2 circuits (see for a definition of Class 2 circuits). UL 48 does not require bonding or grounding for self-contained off-grid PV powered signs operating within the limits of Class 2 voltages. A selfcontained off-grid PV powered sign having the photovoltaic panel as part of the sign housing and having all circuits operating at 30-volt dc or less is not required to be grounded or to comply with the bonding requirements Photovoltaic (PV) Powered Sign. (Electric Signs and Outline Lighting) Definitions. Photovoltaic (PV) Powered Sign. A complete sign powered by solar energy consisting of all components and subassemblies for installation either as an off-grid standalone, on-grid interactive, or non-grid interactive system Photovoltaic (PV) Powered Sign. All field wiring of components and subassemblies for an off-grid stand-alone, on-grid interactive, or non-grid interactive PV installation shall be installed in accordance with Article 690, as applicable, , and the PV powered sign installation instructions. (A) Equipment. Inverters, motor generators, PV modules, PV panels, ac PV modules, dc combiners, dc-ac converters, and charge controllers intended for use in PV powered sign systems shall be listed for PV application NEC Significant Code Changes Part 3 7

10 (B) Wiring. Wiring from a photovoltaic panel or wiring external to the PV sign body shall be: (1) Listed, labeled, and suitable for photovoltaic applications (2) Routed to closely follow the sign body or enclosure (3) As short as possible and secured at intervals not exceeding 0.91 m (3 ft) (4) Protected where subject to physical damage (C) Flexible Cords and Cables. Flexible cords and cables shall comply with Article 400 and be identified as extra hard usage, rated for outdoor use, and water and sunlight resistant. (D) Grounding. Grounding a PV powered sign shall comply with Article 690, Part V and (E) Disconnecting Means. The disconnecting means for a PV powered sign shall comply with Article 690, Part III and (F) Battery Compartments. Battery compartments shall require a tool to open. Article 605 Office Furnishings New (C) Freestanding-Type Office Furnishings, Cord- and Plug-Connected An individual office furnishing or groups of interconnected individual office furnishings now cannot contain more than thirteen 15- ampere, 125-volt receptacles. For purposes of this requirement, a receptacle is considered up to two (simplex) receptacles provided within a single enclosure and that are within 0.3 m (1 ft) of each other, or one duplex receptacle. For clarification, a couple of changes were instituted at 605.9(C). First, the term receptacle outlets was changed to receptacles. This change moves the requirement away from the defined term of receptacle outlet where one or more receptacles can be installed. A new last sentence states that For purposes of this requirement, a receptacle is considered (1) up to two (simplex) receptacles provided within a single enclosure and that are within 0.3 m (1 ft) of each other or (2) one duplex receptacle Freestanding-Type Office Furnishings, Cord- and Plug-Connected. Individual office furnishings of the freestanding type, or groups of individual office furnishings that are electrically connected, are mechanically contiguous, and do not exceed 9.0 m (30 ft) when assembled, shall be permitted to be connected to the 2017 NEC Significant Code Changes Part 3 8

11 building electrical system by a single flexible cord and plug, provided that all of the conditions of 605.9(A) through (D) are met. (C) Receptacle Outlets, Maximum. An individual office furnishing or groups of interconnected individual office furnishings shall not contain more than ampere, 125- volt receptacle outletsreceptacles. For purposes of this requirement, a receptacle is considered (1) up to two (simplex) receptacles provided within a single enclosure and that are within 0.3 m (1 ft) of each other or (2) one duplex receptacle. Article 610 Cranes and Hoists Deletion (B)(3) Branch-Circuit Short-Circuit and Ground-Fault Protection. (Cranes and Hoists) Previous language at (B)(3) permitted taps to crane or hoist brake coils without separate overcurrent protection. This provision has been deleted for the 2017 NEC as taps to brake coils should follow the same tap rules as every other installation. Traditionally, crane or hoist brakes were tapped from the motor leads with relatively short conductors, which was the genesis of this brake coil provision. However, with the advent of variable frequency drives and other electronic controls, typically a longer conductor is run between the control cabinet and the brake coil on most newly-installed cranes or hoist Branch-Circuit Short-Circuit and Ground-Fault Protection. (Cranes and Hoists) Branch circuits shall be protected in accordance with (A). Branch-circuit taps, where made, shall comply with (B). (B) Taps. (1) Multiple Motors. Where two or more motors are connected to the same branch circuit, each tap conductor to an individual motor shall have an ampacity not less than one-third that of the branch circuit. Each motor shall be protected from overload according to (2) Control Circuits. Where taps to control circuits originate on the load side of a branchcircuit protective device, each tap and piece of equipment shall be protected in accordance with (3) Brake Coils. Taps without separate overcurrent protection shall be permitted to brake coils NEC Significant Code Changes Part 3 9

12 Article 620 Elevators, Dumbwaiters, Escalators, Moving Walks, Platform Lifts, and Stairway Chairlifts New Short-Circuit Current Rating. (Elevators, Etc.) with a short-circuit current rating at all. A new marking requirement for short-circuit current ratings on elevator control panels was incorporated into for the 2017 NEC. This new requirement also prohibits an elevator control panel from being installed where the available short-circuit current exceeds its short-circuit current rating. Elevator control panels are being misapplied in a large number of applications due to an inadequate short-circuit current rating for the equipment. These elevator control panels are often installed without being marked This new requirement establishes that the short-circuit current rating must be marked on the elevator control panel and that this short-circuit current rating is determined by its listing process or by an approved method. An informational note was also added identifying UL 508A-2013 (Standard for Industrial Control Panels), Supplement SB, as an example of an approved method Short-Circuit Current Rating. (Elevators, Etc.) (A) Marking. Where an elevator control panel is installed, it shall be marked with its short-circuit current rating, based on one of the following: (1) Short-circuit current rating of a listed assembly (2) Short-circuit current rating established utilizing an approved method Informational Note: UL 508A-2013, Supplement SB, is an example of an approved method. (B) Installation. The elevator control panel shall not be installed where the available shortcircuit current exceeds its short-circuit current rating, as marked in accordance with (A) NEC Significant Code Changes Part 3 10

13 Article 625 Electric vehicle Charging System New Definitions. (Electric Vehicle Charging System) In anticipation of a growing trend in the charging of electric vehicles (EV), two new definitions were added to Article 625 for the 2017 NEC. Due to developing technologies, the definition of Wireless Power Transfer (WPT) and Wireless Power Transfer Equipment (WPTE) were added at to cover upcoming charging systems. These definitions are derived from the terminology set forth in a Society of Automotive Engineers (SAE) standard, SAE J2954. This standard, Wireless Charging of Electric and Plug-in Hybrid Vehicles, establishes minimum performance and safety criteria for wireless charging of electric and plug-in hybrid vehicles. This SAE International standard creates a technology matrix to evaluate multiple wireless charging technologies (inductive, magnetic resonance, etc.), identifiable charging locations such as residential or on-road (parking lot, roadway) locations, as well as Levels 1, 2, and 3 wireless charging stations. Wireless charging of electric vehicles offers the advantage of charging without having to physically connect the electric vehicle to the electrical system. The new definitions support the new requirements added in the newly established Part IV of Article 625 titled, Wireless Power Transfer Equipment Definitions. (Electric Vehicle Charging System) Wireless Power Transfer (WPT). The transfer of electrical energy from a power source to an electrical load via electric and magnetic fields or waves by a contactless inductive means between a primary and a secondary device. Wireless Power Transfer Equipment (WPTE). Equipment consisting of a charger power converter and a primary pad. The two devices are either separate units or contained within one enclosure NEC Significant Code Changes Part 3 11

14 Deletion Electric Vehicle Coupler A revision to for the 2017 NEC included the deletion of requirements about polarization and non-interchangeability of EV couplers. Polarization is important for EV connectors and inlets so that they cannot be mated in any way that would allow the power contacts to mate with other contacts, thereby creating a potential hazard. This EV connector is a construction feature that is evaluated as part of the product standard and involves a specific polarization test in UL The pin configuration on this type of connector is not required to be marked to indicate which contact is associated with which circuit (power, pilot, communication, or ground). As this is a feature associated with a given configuration, it does not lend itself to easy verification or practical enforcement in the field Electric Vehicle Coupler. The electric vehicle coupler shall comply with (A) through (F)(D). (A) Polarization. The electric vehicle coupler shall be polarized. Exception: A coupler that is part of a listed electric vehicle supply equipment. (B) Noninterchangeability. The electric vehicle coupler shall have a configuration that is noninterchangeable with wiring devices in other electrical systems. Nongroundingtype electric vehicle couplers shall not be interchangeable with grounding-type electric vehicle couplers. (C)(A) Construction and Installation. The electric vehicle coupler shall be constructed and installed so as to guard against inadvertent contact by persons with parts made live from the electric vehicle supply equipment or the electric vehicle battery. (D)(B) Unintentional Disconnection. The electric vehicle coupler shall be provided with a positive means to prevent unintentional disconnection. (E)(C) Grounding Pole. The electric vehicle coupler shall be provided with a grounding pole, unless provided as part of a listed isolated electric vehicle supply equipment system. (F)(D) Grounding Pole Requirements. If a grounding pole is provided, the electric vehicle coupler shall be so designed that the grounding pole connection is the first to make and the last to break contact NEC Significant Code Changes Part 3 12

15 New - Article 625, Part IV Wireless Power Transfer Equipment (Electric Vehicle Charging System) A new Part IV of Article 625 entitled, Wireless Power Transfer Equipment was added to Article 625, as well as two new definitions, Wireless Power Transfer (WPT) and Wireless Power Transfer Equipment (WPTE) were added at The technology behind wireless EV charging creates a connection between a transmitting pad on ground level (such as a garage floor) and a receiving pad integrated on the bottom of the electric vehicle. The transmitting pad on the ground level is connected to a 240-volt source and generates a magnetic field of a certain frequency. When the coil in the EV receiving pad is tuned to oscillate at the same frequency, the magnetic field will generate a current in the receiving coil, charging the vehicle s battery. New Part IV of Article 625 consists of two sections. New includes requirements for grounding the non-ferrous metal primary pad base plate unless the listed wireless power transfer equipment employs a double-insulation system. The creation of new provides construction requirements that are to be provided during the installation of wireless power transfer equipment Grounding. The primary pas base plate shall be of a non-ferrous metal and shall be grounded unless the listed WPTE employs a double-insulation system. The base plate shall be sized to match the size of the primary pad enclosure Construction. (A) Type. The charger power converter, where integral to the primary pad, shall comply with (C). The charger power converter, if not integral to the primary pad, shall be provided with a minimum Type 3R enclosure rating. (B) Installation. If the charger power converter is not integral to the primary pad, it shall be mounted at a height of not less than 450 mm (18 in.) above the floor level for indoor locations 2017 NEC Significant Code Changes Part 3 13

16 or 600 mm (24 in.) above grade level for outdoor locations. The charger power converter shall be mounted in one of the following forms: (1) Pedestal (2) Wall or pole (3) Building or structure (4) Raised concrete pad (C) Primary Pad. The primary pad shall be installed on the surface, embedded in the surface of the floor with its top flush with the surface, or embedded in the surface of the floor with its top below the surface. This included primary pas constructions with the charger power converter located in the primary pas enclosure. (1) If the primary pad is located in an area requiring snow removal, it shall not be located on or above the surface. Exception: Where installed on private property where snow removal is done manually, the primary pad shall be permitted above the surface. (2) The enclosure shall be provided with a suitable enclosure rating minimum Type 3. If the primary pad is located in an area subject to severe climatic conditions (e.g. flooding), it shall be suitably rated for those conditions or be provided with a suitably rated enclosure. (D) Protection of the Output Cable. The output cable to the primary pad shall be secured in place over its entire length for the purpose of restricting its movement and to prevent strain at the connection points. If installed in conditions where drive over could occur, the cable shall be provided with supplemental protection. Where the charger power converter is a part of the primary pad assembly, the power supply cord to the primary pad shall also be protected. (E) Other Wiring Systems. Other wiring systems and fittings specifically listed for use on the WPTE shall be permitted NEC Significant Code Changes Part 3 14

17 Article 645 Information Technology Equipment Revision (B) Other Articles. (Information Technology Equipment) Article 645 covers equipment, power-supply wiring, equipment interconnecting wiring, and grounding of information technology (IT) equipment and systems in an IT equipment room. Wiring methods in IT equipment rooms are allowed to be installed and maintained per the requirements of Article 645 as long as the room meets all the requirements of To allow for quick and relatively easy interchange of wiring methods under raised floors in an IT equipment room, some of the wiring method requirements (securing and supporting, etc.) in Article 645 are not as stringent as in NEC Chapters 1 4. Because of these less restrictive requirements in Article 645 for IT equipment rooms, all the requirements of must be met for the room to be classified as an IT equipment room Other Articles. (Information Technology Equipment) Circuits and equipment shall comply with 645.3(A) through (G)(I), as applicable. (B) Wiring and Cabling in Other Spaces Used for Environmental Air (Plenums). The following sections and tables shall apply to wiring and cabling in a plenum other spaces used for environmental air (plenums) above an information technology equipment room: (1) Wiring methods: (C)(1) (2) Class 2, Class 3, and PLTC cables: (C) and Table (3) Fire alarm systems: (B)(2), (C) (C), and Table (4) Optical fiber cables: (C), and Table (a) (5) Communications circuits: (C) (C) and Table (a), (b), and (c) (6) CATV and radio distribution systems: (C) and Table (a) 2017 NEC Significant Code Changes Part 3 15

18 Revision (E) Supply Circuits and Interconnecting Cables. (Information Technology Equipment), Under Raised Floors The entire first level subdivision at 645.5(E) has been revised and re-organized for usability and clarity. A list format was incorporated where possible. The new revised parent text at 645.5(E) organizes the conditions for using the underfloor area for wiring from an installation requirements standpoint. Three new second level subdivisions then lay out the requirements for branchcircuit wiring [645.5(E)(1)], data, cords, interconnection cables and grounding conductors [645.5(E)(2)], and optical fiber cabling [645.5(E)(3)]. The revised under-floor wiring method requirements are stated in a manner consistent with by first referencing the general wiring methods (as applicable) in NEC Chapters 3, and Articles 725 (Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits) and Article 770 (Fire Alarm Systems) and then stating which alternate wiring methods are acceptable Supply Circuits and Interconnecting Cables. (Information Technology Equipment) (E) Under Raised Floors. Where the area under the floor is accessible and openings minimize the entrance of debris beneath the floor, power cables, communications cables, connecting cables, interconnecting cables, cord-and-plug connections, and receptacles associated with the information technology equipment shall be permitted under a raised floor of approved construction. The installation requirement shall comply with 645.5(E)(1) through (3)., provided the following conditions are met: (1) The raised floor is of approved construction, and the area under the floor is accessible. (2) The branch-circuit supply conductors to receptacles or field-wired equipment are in rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, electrical metallic tubing, electrical nonmetallic tubing, metal wireway, nonmetallic wireway, surface metal raceway with metal cover, surface nonmetallic raceway, flexible metal conduit, liquid-tight flexible metal conduit, or liquidtight flexible nonmetallic conduit, Type MI cable, Type MC cable, or Type AC cable and associated metallic and nonmetallic boxes or enclosures. These supply conductors shall be installed in accordance with the requirements of NEC Significant Code Changes Part 3 16

19 (1) Installation Requirements for Branch Circuit Supply Conductors Under a Raised Floor. (a) These The supply conductors shall be installed in accordance with the requirements of (b) In addition to the wiring methods of (C), the following wiring methods shall also be permitted: (1) Rigid metal conduit (2) Rigid nonmetallic conduit (3) Intermediate metal conduit (4) Electrical metallic tubing (5) Electrical nonmetallic tubing (6) Metal wireway (7) Nonmetallic wireway (8) Surface metal raceway with metal cover (9) Surface nonmetallic raceway (10) Flexible metal conduit (11) Liquidtight flexible metal conduit (12) Liquidtight flexible nonmetallic conduit (13) Type MI cable (14) Type MC cable (15) Type AC cable (16) Associated metallic and nonmetallic boxes or enclosures (17) Type TC power and control tray cable (2) Installation Requirements for Electrical Supply Cords, Data Cables, Interconnecting Cables, and Grounding Conductors Under a Raised Floor. The following cords, cables, and conductors shall be permitted to be installed under a raised floor: (1) Supply cords of listed information technology equipment in accordance with 645.5(B) (2) Interconnecting cables enclosed in a raceway (3) Equipment grounding conductors (4) In addition to wiring installed in compliance with (C), Types CL2R, CL3R, CL2, and CL3 and substitute cables including CMP, CMR, CM, and CMG installed in accordance with (A), shall be permitted under raised floors. Informational Note: Figure (A) illustrates the cable substitution hierarchy for Class 2 and Class 3 cables. (5) Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an information technology equipment room Informational Note: One method of defining fire resistance is by establishing that the cables do not spread fire to the top of the tray in the UL Flame Exposure, Vertical Tray Flame Test in 2017 NEC Significant Code Changes Part 3 17

20 UL , Standard for Safety for Vertical-Tray Fire-Propagation and Smoke-Release Test for Electrical and Optical-Fiber Cables. The smoke measurements in the test method are not applicable. Another method of defining fire resistance is for the damage (char length) not to exceed 1.5 m (4 ft 11 in.) when performing the CSA Vertical Flame Test Cables in Cable Trays, as described in CSA C22.2 No M , Test Methods for Electrical Wires and Cables. (3) Supply cords of listed information technology equipment are in accordance with 645.5(B). (4) Ventilation in the underfloor area is used for the information technology equipment room only, except as provided in 645.4(2). (5) Openings in raised floors for cords and cables protect cords and cables against abrasion and minimize the entrance of debris beneath the floor. (6) Cables, other than those covered in 645.5(E)(2) and (E)(3), are one of the following: a. Listed Type DP cable having adequate fire-resistant characteristics suitable for use under raised floors of an information technology equipment room b. Interconnecting cables enclosed in a raceway c. Cable type designations shown in Table 645.5(E)(6) d. Equipment grounding conductors (3) Installation Requirements for Optical Fiber Cables Under a Raised Floor. In addition to optical fiber cables installed in accordance with (C), Types OFNR, OFCR, OFN, and OFC shall be permitted under raised floors. Table from the x-ray (6) Cable Types Permitted Under Raised Floors [Table 645.5(E)(6) has been deleted] 2017 NEC Significant Code Changes Part 3 18

21 Surge Protection for Critical Operations Data Systems. (Information Technology Equipment) Surge protection is now required for critical operations data systems by the provisions of new This new surge protection requirement correlates with (D) for Critical Operations Power Systems. Section (D) calls for surge protection devices to be provided at all facility distribution voltage levels of a critical operations power system. This requirement often results in critical operations data centers including localized surge protection as part of the manufactured equipment. This requirement at addresses an additional level of surge protection that is needed as close as possible to the incoming supply for the critical operations data system. For surge protection to be effective, multiple levels of surge protection typically must be provided Surge Protection for Critical Operations Data Systems. (Information Technology Equipment) Surge protection shall be provided for critical operations data systems NEC Significant Code Changes Part 3 19

22 New/Revision - Article 650 Pipe Organs Article 650 was revised by adding for three definitions for electronic organ, pipe organ, and sounding apparatus. Previous editions of Article 650 had no definitions; these definitions are important terms for the application of this article. Another change was the addition of titled, Protection from Accidental Contact. Because the sounding apparatus has exposed circuits, its wiring is required to be located within a lockable enclosure (typically the organ chamber) where the exterior pipes form part of the enclosure. Access to the interior of the sounding apparatus should be limited to qualified personnel. Typically, the exterior pipes are tightly spaced so the combination of exterior pipes and walls of a room prevent unauthorized access. In other situations, the pipes are covered by decorative millwork that permits sound to pass through it Scope. This article covers those electrical circuits and parts of electrically operated pipe organs that are employed for the control of the keyboards and of the sounding apparatus, typically organ pipesand keyboards. Informational Note: The typical pipe organ is a very large musical instrument that is built as part of a building or structure Definitions. Electronic Organ. A musical instrument that imitates the sound of a pipe organ by producing sound electronically. Informational Note: Most new electronic organs produce sound digitally and are called digital organs. Pipe Organ. A musical instrument that produces sound by driving pressurized air (called wind) through pipes selected via a keyboard. Sounding Apparatus. The sound-producing part of a pipe organ, including, but not limited to, pipes, chimes, bells, the pressurized air (wind)-producing equipment (blower), associated controls, and power equipment. Informational Note: The sounding apparatus is also referred to as the pipe organ chamber Protection from Accidental Contact. The wiring of the sounding apparatus shall be within the lockable enclosure (organ chamber) where the exterior pipes shall be permitted to form part of the enclosure. Informational Note: Access to the sounding apparatus and the associated circuitry is restricted by an enclosure. In most pipe organ installations, exterior pipes form part of the enclosure. In other installations, the pipes are covered by millwork that permits the passage of sound NEC Significant Code Changes Part 3 20

23 Article 660 X-Ray Equipment Revision Disconnecting Means. (X-Ray Equipment) The disconnecting means for X- ray equipment is now required to be located within sight from the X-ray control and readily accessible. This revised text will ensure the proper location of the disconnecting means, with the use of the defined term within sight. A new exception to this disconnecting means rule was added for X-ray equipment in industrial locations where a disconnecting means would be impracticable or introduces additional or increased hazards to persons or property and in industrial installations (with written safety procedures) where conditions of maintenance and supervision ensure that only qualified persons service the equipment. These conditions are quite common in industrial applications Disconnecting Means. (X-Ray Equipment) A disconnecting means of adequate capacity for at least 50 percent of the input required for the momentary rating, or 100 percent of the input required for the longtime rating, of the X-ray equipment, whichever is greater, shall be provided in the supply circuit. The disconnecting means shall be operable from a location readily accessible from located within sight from the X-ray control and readily accessible. For equipment connected to a 120-volt, nominal, branch circuit of 30 amperes or less, a grounding-type attachment plug cap and receptacle of proper rating shall be permitted to serve as a disconnecting means. Exception: The disconnecting means for the X-ray equipment shall not be required under either of the following conditions, provided that the controller disconnecting means is lockable in accordance with : (1) Where such a location of the disconnecting means for the X-ray equipment is impracticable or introduces additional or increased hazards to persons or property (2) In industrial installations, with written safety procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment NEC Significant Code Changes Part 3 21

24 Article 670 Industrial Machinery New Surge Protection. (Industrial Machinery) A new requirement has been added to Article 670 applying to Industrial machinery with safety interlock circuits. These industrial machinery applications will now be required to be provided with surge protection. A study entitled, Data Assessment for Electrical Surge Protective Devices, commissioned by the NFPA Fire Protection Research Foundation, provided results of a 2013 and 2014 survey of facility managers concerning surge damage. This survey shows that 26 percent of the responders had damage to safety interlocking systems on machines due to electrical surges. These safety interlocking systems are in place to protect workers from serious injuries and death due to interactions with the machinery Surge Protection. (Industrial Machinery) Industrial machinery with safety interlock circuits shall have surge protection installed NEC Significant Code Changes Part 3 22

25 Article 680 Swimming Pools, Fountains, and Similar Installations New and Part VIII of Article 680 Definitions, Swimming Pools, Fountains, and Similar Installations A new definition for an Electrically Powered Pool Lift at along with a new Part VIII ( through ) were incorporated into Article 680 for the 2017 NEC. These lifts are defined as an electrically powered lift that provides accessibility to and from a pool or spa for people with disabilities. These lifts allow persons with disabilities to have access to public swimming pools, spas, and hot tubs Before the 2017 NEC, installation of these mandated powered pool lifts has been without compliance to any NEC requirements, in particular, requirements in Article Definitions. (Swimming Pools, Fountains, and Similar Installations) Electrically Powered Pool Lift. An electrically powered lift that provides accessibility to and from a pool or spa for people with disabilities. Part VIII. Electrically Powered Pool Lifts General. Electrically powered pool lifts as defined in shall comply with Part VIII of this article. They shall not be required to comply with other parts of this article Equipment Approval. Lifts shall be listed and identified for swimming pool and spa use. Exception No. 1: Lifts where the battery is removed for charging at another location and the battery is rated less than or equal to the low-voltage contact limit shall not be required to be listed or labeled. Exception No. 2: Solar-operated or -recharged lifts where the solar panel is attached to the lift and the battery is rated less than or equal to 24 volts shall not be required to be listed or labeled. Exception No. 3: Lifts that are supplied from a source not exceeding the low-voltage contact limit and supplied by listed transformers or power supplies that comply with (A)(2) shall not be required to be listed Protection. Pool lifts connected to premises wiring and operated above the lowvoltage contact limit shall be provided with GFCI protection for personnel NEC Significant Code Changes Part 3 23

26 Bonding. Lifts shall be bonded in accordance with (B)(5) and (B)(7) Switching Devices. Switches and switching devices that are operated above the lowvoltage contact limit shall comply with (C) Nameplate Marking. Electrically powered pool lifts shall be provided with a nameplate giving the identifying name and model and rating in volts and amperes, or in volts and watts. If the lift is to be used on a specific frequency or frequencies, it shall be so marked. Battery-powered pool lifts shall indicate the type reference of the battery or battery pack to be used. Batteries and battery packs shall be provided with a battery type reference and voltage rating. Exception: Nameplate ratings for battery-powered pool lifts shall only need to provide a rating in volts in addition to the identifying name and model. Revision Definitions. (Swimming Pools, Fountains, and Similar Installations) is always installed on or above the ground. Further clarification was instituted with the phrase constructed on or above the ground added before storable/portable nonmetallic, polymeric or inflatable tubs, spas, or pools regardless of the dimension. This addition clarifies that a storable/portable pool, spa, or hot tub with nonmetallic, molded polymeric walls or inflatable fabric walls regardless of dimension Definitions. (Swimming Pools, Fountains, and Similar Installations) Storable Swimming, Wading, or Immersion Pools; or Storable/ Portable Spas and Hot Tubs. Those Swimming, wading, or immersion pools that are intended to be stored when not in use, constructed on or above the ground and are capable of holding water to a maximum depth of 1.0 m (42 in.), or a pool, spa, or hot tub constructed on or above the ground, with nonmetallic, molded polymeric walls or inflatable fabric walls regardless of dimension NEC Significant Code Changes Part 3 24

27 New Grounding and Bonding Terminals. (Swimming Pools, Fountains, and Similar Installations) listed for direct burial applications as well. A new grounding and bonding termination requirement was added at This new requirement calls for grounding and bonding terminals to be identified for use in wet and corrosive environments. Field-installed grounding and bonding connections installed in a damp, wet, or corrosive environment will need to be composed of copper, copper alloy, or stainless steel. These grounding and bonding terminations must also be Grounding and Bonding Terminals. (Swimming Pools, Fountains, and Similar Installations) Grounding and bonding terminals shall be identified for use in wet and corrosive environments. Field-installed grounding and bonding connections in a damp, wet, or corrosive environment shall be composed of copper, copper alloy, or stainless steel. They shall be listed for direct burial use NEC Significant Code Changes Part 3 25

28 Deletion - Table Underground Wiring Location. (Swimming Pools, Fountains, and Similar Installations) Underground wiring is now permitted to be installed in close proximity to the pool, and no consideration needs to be given as to whether this wiring is necessary to supply pool equipment. The wiring methods employed are to be rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride conduit, reinforced thermosetting resin conduit, or Type MC cable, suitable for the conditions subject to that location. Underground wiring shall not be permitted to be installed under the pool unless this wiring is necessary to supply pool equipment permitted by Article 680. The minimum burial depth cover requirements will now be facilitated by Table 300.5, and Table for minimum cover depths around pools has been deleted Underground Wiring Location. (Swimming Pools, Fountains, and Similar Installations) Underground wiring shall not be permitted under the pool or within the area extending 1.5 m (5 ft) horizontally from the inside wall of be permitted where installed in rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride conduit, reinforced thermosetting resin conduit, or Type MC cable, suitable for the conditions subject to that location. Underground wiring shall not be permitted under the pool unless this wiring is necessary to supply pool equipment permitted by this article. Where space limitations prevent wiring from being routed a distance 1.5 m (5 ft) or more from the pool, such wiring shall be permitted where installed in complete raceway systems of rigid metal conduit, intermediate metal conduit, or a nonmetallic raceway system. All metal conduit shall be corrosion resistant and suitable for the location. The Minimum cover depth shall be as given in Table Table (Table Minimum Cover Depths has been deleted) 2017 NEC Significant Code Changes Part 3 26

29 Revision and New and Equipment Rooms and Pits. (Swimming Pools, Fountains, and Similar Installations) and Corrosive Environment In addition to proper drainage as required by previous , now requires electrical equipment located in equipment rooms or pits to be suitable for the environment in accordance with 300.6, which calls for materials suitable for the environment in which they are to be installed. New requirements at detail the corrosion resistance of wiring methods needed in swimming pool installations where chemicals are stored. Previous editions of the code did not address corrosion protection Equipment Rooms and Pits. (Swimming Pools, Fountains, and Similar Installations)Electrical equipment shall not be installed in rooms or pits that do not have drainage that prevents water accumulation during normal operation or filter maintenance. Equipment shall be suitable for the environment in accordance with Informational Note: Chemicals such as chlorine cause severe corrosive and deteriorating effects on electrical connections, equipment, and enclosures when stored and kept in the same vicinity. Adequate ventilation of indoor spaces such as equipment and storage rooms is addressed by ANSI/APSP-11, Standard for Water Quality in Public Pools and Spas, and can reduce the likelihood of the accumulation of corrosive vapors Corrosive Environment. (A) General. Areas where pool sanitation chemicals are stored, as well as areas with circulation pumps, automatic chlorinators, filters, open areas under decks adjacent to or abutting the pool structure, and similar locations shall be considered to be a corrosive environment. The air in such areas shall be considered to be laden with acid, chlorine, and bromine vapors, or any combination of acid, chlorine, or bromine vapors, and any liquids or condensation in those areas shall be considered to be laden with acids, chlorine, and bromine vapors, or any combination of acid, chlorine, or bromine vapors. (B) Wiring Methods. Wiring methods in the areas described in (A) shall be listed and identified for use in such areas. Rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride conduit, and reinforced thermosetting resin conduit shall be considered to be resistant to the corrosive environment specified in (A) NEC Significant Code Changes Part 3 27

30 Revision/Deletion (A) (Swimming Pools, Fountains, and Similar Installations) The restricted wiring methods previously described in (A)(1) through (A)(5) will now only apply in areas where protection from physical damage is needed or where protection from environmental conditions associated with wet, damp, and corrosive conditions are present. Where installed in noncorrosive environments (such as in the interior of a dwelling unit), branch circuits wiring methods for permanently installed swimming pool pump motors only need to comply with the general requirements of wiring methods mentioned in Chapter 3 of the NEC Motors. (Swimming Pools, Fountains, and Similar Installations) (A) Wiring Methods. The wiring to a pool motor shall comply with (A) (1) unless modified for specific circumstances by (A)(2), (A)(3), (A)(4), or (A)(5). (1) General. The branch circuits for pool-associated motors shall be installed in rigid metal conduit, intermediate metal conduit, rigid polyvinyl chloride conduit, reinforced thermosetting resin conduit,wiring methods installed in the corrosive environment described in shall comply with (B) or shall be Type MC cable listed for the that location. Other wiring methods and materials shall be permitted in specific locations or applications as covered in this section. Any Wiring methods installed in these locations employed shall contain an insulated copper equipment grounding conductor sized in accordance with but not smaller Where installed in noncorrosive environments, branch circuits shall comply with the general requirements in Chapter 3. (2) On or Within Buildings. Where installed on or within buildings, electrical metallic tubing shall be permitted. (3) (2) Flexible Connections. Where necessary to employ flexible connections at or adjacent to the motor, liquidtight flexible metal or liquid-tight flexible nonmetallic conduit with approved fittings shall be permitted. (4) One-Family Dwellings. In the interior of dwelling units, or in the interior of accessory buildings associated with a dwelling unit, any of the wiring methods recognized in Chapter 3 of this Code that comply with the provisions of this section shall be permitted. Where run in a 2017 NEC Significant Code Changes Part 3 28

31 cable assembly, the equipment grounding conductor shall be permitted to be uninsulated, but it shall be enclosed within the outer sheath of the cable assembly. (5) (3) Cord-and-Plug Connections. Pool-associated motors shall be permitted to employ cord-and-plug connections. The flexible cord shall not exceed 900 mm (3 ft) in length. The flexible cord shall include a copper equipment grounding conductor sized in accordance with but not smaller than 12 AWG. The cord shall terminate in a grounding-type attachment plug. Revision/Deletion (A)(2) Lighting, Receptacles, and Equipment. (Swimming Pools, Fountains, and Similar Installations) Receptacles that supply power for pool pump motors or other loads directly related to the circulation and sanitation system can now be located not less than 1.83 m (6 ft) from the inside walls of the pool, provided the receptacle(s) are of the grounding type and equipped with GFCI protection Lighting, Receptacles, and Equipment. (Swimming Pools, Fountains, and Similar Installations) (A) Receptacles. (2) Circulation and Sanitation System, Location. Receptacles that provide power for waterpump motors or for other loads directly related to the circulation and sanitation system shall be located at least 3.0 m (10 ft) 1.83 m (6 ft) from the inside walls of the pool., or not less than 1.83 m (6 ft) from the inside walls of the pool if they meet all of the following conditions: These receptacles shall have GFCI protection and be of the grounding type. (1) Consist of single receptacles (2) Are of the grounding type (3) Have GFCI protection 2017 NEC Significant Code Changes Part 3 29

32 New (B)(7) Low-Voltage Gas-Fired Luminaires, Decorative Fireplaces, Fire Pits, and Similar Equipment New provisions were added in (B)(7) to specifically address low-voltage gas-fired luminaires, decorative fireplaces, fire pits, and similar equipment. With the inclusion of electronic ignitors for these devices, NEC regulations were needed for this type of lowvoltage, gas-fired equipment. These features have become one of the most popular outdoor additions to a pool area, but they also require the coordination of several key elements such as masonry, gas and plumbing, stonework and now electrical with the introduction of electronic igniters to these units. These new provisions for low-voltage gas fire equipment were needed with the conversion of gas luminaire technology away from manual ignition and toward the use of lowvoltage electronic ignitors, bringing formerly gas-only devices and appliances under the requirements of the NEC as pertaining to the electrical control and low-voltage ignitor equipment Lighting, Receptacles, and Equipment. (Swimming Pools, Fountains, and Similar Installations) (B) Luminaires, Lighting Outlets, and Ceiling-Suspended (Paddle) Fans. (7) Low-Voltage Gas-Fired Luminaires, Decorative Fireplaces, Fire Pits, and Similar Equipment. Listed low-voltage gas-fired luminaires, decorative fireplaces, fire pits, and similar equipment using low-voltage ignitors that do not require grounding, and are supplied by listed transformers or power supplies that comply with (A)(2) with outputs that do not exceed the low-voltage contact limit shall be permitted to be located less than 1.5 m (5 ft) from the inside walls of the pool. Metallic equipment shall be bonded in accordance with the requirements in (B). Transformers or power supplies supplying this type of equipment shall be installed in accordance with the requirements in Metallic gas piping shall be bonded in accordance with the requirements in (B) and (B)(7) NEC Significant Code Changes Part 3 30

33 Revision/Deletion Feeders. (Swimming Pools, Fountains, and Similar Installations) The previous (B) for grounding of swimming pool panelboard feeders was deleted in its entirety as grounding provisions for swimming pool panelboard feeders have been incorporated into the revised text at (A). The revised text at (A) requires restricted wiring methods only in areas where harsh conditions (such as physical damage, environmental conditions, corrosive conditions, etc.) are present. Chapter 3 wiring methods are now otherwise permitted Feeders. (Swimming Pools, Fountains, and Similar Installations) These provisions shall apply to any feeder on the supply side of panel-boards supplying branch circuits for pool equipment covered in Part II of this article and on the load side of the service equipment or the source of a separately derived system. (A) Wiring Methods. (1) (A) Feeders. Feeders shall be installed in rigid metal conduit or intermediate metal conduit. The following wiring methods shall be permitted if not subject to physical damage: Where feeders are installed in corrosive environments as described in , the wiring method of that portion of the feeder shall be as required in (B) or shall be liquid-tight flexible nonmetallic conduit. Wiring methods installed in corrosive environments as described in shall contain an insulated copper equipment grounding conductor sized in accordance with Table , but not smaller than 12 AWG. Where installed in noncorrosive environments, feeders shall comply with the general requirements in Chapter 3. (1) Liquidtight flexible nonmetallic conduit (2) Rigid polyvinyl chloride conduit (3) Reinforced thermosetting resin conduit (4) Electrical metallic tubing where installed on or within a building (5) Electrical nonmetallic tubing where installed within a building (6) Type MC cable where installed within a building and if not subject to corrosive environment 2017 NEC Significant Code Changes Part 3 31

34 (2) (B) Aluminum Conduit. Aluminum conduit shall not be permitted in the pool area where subject to corrosion. (B) Grounding. An equipment grounding conductor shall be installed with the feeder conductors between the grounding terminal of the pool equipment panelboard and the grounding terminal of the applicable service equipment or source of a separately derived system. For other than feeders to separate buildings that do not utilize an insulated equipment grounding conductor in accordance with (B)(2), this equipment grounding conductor shall be insulated. (1) Size. This conductor shall be sized in accordance with but not smaller than 12 AWG. On separately derived systems, this conductor shall be sized in accordance with (A)(3) but not smaller than 8 AWG. (2) Separate Buildings. A feeder to a separate building or structure shall be permitted to supply swimming pool equipment branch circuits, or feeders supplying swimming pool equipment branch circuits, if the grounding arrangements in the separate building meet the requirements in (B) NEC Significant Code Changes Part 3 32

35 New (B)(1), Ex. and (B)(2), Ex. Specialized Pool Equipment. (Swimming Pools, Fountains, and Similar Installations) Two exceptions were added below the parent text of (B)(1) and (B)(2) recognizing pool cover motors that are part of a listed system with ratings not exceeding the low-voltage contact limits, allowing such a low-voltage type motor to be installed within 1.5 m (5 ft) of the inside walls of the pool, and the omission of GFCI protection for said motor Specialized Pool Equipment. (Swimming Pools, Fountains, and Similar Installations) (B) Electrically Operated Pool Covers. (1) Motors and Controllers. The electric motors, controllers, and wiring shall be located not less than 1.5 m (5 ft) from the inside wall of the pool unless separated from the pool by a wall, cover, or other permanent barrier. Electric motors installed below grade level shall be of the totally enclosed type. The device that controls the operation of the motor for an electrically operated pool cover shall be located such that the operator has full view of the pool. Informational Note No. 1: For cabinets installed in damp and wet locations, see Informational Note No. 2: For switches or circuit breakers installed in wet locations, see Informational Note No. 3: For protection against liquids, see Exception: Motors that are part of listed systems with ratings not exceeding the low-voltage contact limit that are supplied by listed transformers or power supplies that comply with (A)(2) shall be permitted to be located less than 1.5 m (5 ft) from the inside walls of the pool. (2) Protection. The electric motor and controller shall be connected to a branch circuit protected by a ground-fault circuit interrupter. Exception: Motors that are part of listed systems with ratings not exceeding the low-voltage contact limit that are supplied by listed transformers or power supplies that comply with (A)(2) NEC Significant Code Changes Part 3 33

36 New Gas-Fired Water Heater. (Swimming Pools, Fountains, and Similar Installations) New provisions were added requiring branch circuits serving gasfired swimming pool and spa water heaters operating at voltages above the low-voltage contact limit to be provided with GFCI protection for personnel Gas-Fired Water Heater. (Swimming Pools, Fountains, and Similar Installations) Circuits serving gas-fired swimming pool and spa water heaters operating at voltages above the low-voltage contact limit shall be provided with ground-fault circuitinterrupter protection for personnel. Revision/New Bonding. (Hydromassage Bathtubs) The former requirements for equipotential bonding of a hydromassage bathtub were retained and placed into a list format. Section now has two first level subdivisions, (A) and (B), with two exceptions for (A). A list of metallic items located within 1.5 m (5 ft) of the inside walls of the tub were added to the items required to be bonded. A new exception now exempts bonding of small conductive surfaces Bonding. (Hydromassage Bathtubs) Both metal piping systems and grounded metal parts in contact with the circulating water shall be bonded together using a solid copper bonding jumper, insulated, covered, or bare, not smaller than 8 AWG. The bonding jumper shall be connected to the terminal on the circulating pump motor that is intended for this purpose. The bonding jumper shall not be required to be connected to a double insulated circulating pump motor. The 8 AWG or larger solid copper bonding jumper shall be required for equipotential bonding in the area of the hydromassage bathtub and shall not be required to be extended or attached to any remote panelboard, service equipment, or any electrode. The 8 AWG or larger solid copper 2017 NEC Significant Code Changes Part 3 34

37 bonding jumper shall be long enough to terminate on a replacement non-double-insulated pump motor and shall be terminated to the equipment grounding conductor of the branch circuit of the motor when a double-insulated circulating pump motor is used. (A) General. The following parts shall be bonded together: (1) All metal fittings within or attached to the tub structure that are in contact with the circulating water (2) Metal parts of electrical equipment associated with the tub water circulating system, including pump and blower motors (3) Metal-sheathed cables and raceways and metal piping that are within 1.5 m (5 ft) of the inside walls of the tub and not separated from the tub by a permanent barrier (4) All exposed metal surfaces that are within 1.5 m (5 ft) of the inside walls of the tub and not separated from the tub area by a permanent barrier (5) Electrical devices and controls that are not associated with the hydro-massage tubs and that are located within 1.5 m (5 ft) from such units Exception No. 1: Small conductive surfaces not likely to become energized, such as air and water jets, supply valve assemblies, and drain fittings not connected to metallic piping, and towel bars, mirror frames, and similar nonelectrical equipment not connected to metal framing shall not be required to be bonded. Exception No. 2: Double-insulated motors and blowers shall not be bonded. (B) All metal parts required to be bonded by this section shall be bonded together using a solid copper bonding jumper, insulated, covered, or bare, not smaller than 8 AWG. The bonding jumper(s) shall be required for equipotential bonding in the area of the hydromassage bathtub and shall not be required to be extended or attached to any remote panel-board, service equipment, or any electrode. In all installations, a bonding jumper long enough to terminate on a replacement non-double-insulated pump or blower motor shall be provided and shall be terminated to the equipment grounding conductor of the branch circuit of the motor when a double-insulated circulating pump or blower motor is used NEC Significant Code Changes Part 3 35

38 Article 682 Natural and Artificially Made Bodies of Water Revision Ground-Fault Circuit-Interrupter (GFCI) Protection. (Natural and Artificially Made Bodies of Water) GFCI protection for personnel is now required for all 15- and 20- ampere, single-phase, 125-volt through 250-volt receptacles installed outdoors and in or on floating buildings or structures within the electrical datum plane area, not just those receptacles in areas used for storage, maintenance, or repair where portable electric hand tools, electrical diagnostic equipment, or portable lighting equipment are to be used Ground-Fault Circuit-Interrupter (GFCI) Protection. (Natural and Artificially Made Bodies of Water) Fifteen- and 20-ampere single-phase, 125-volt through 250-volt receptacles installed outdoors and in or on floating buildings or structures within the electrical datum plane area that are used for storage, maintenance, or repair where portable electric hand tools, electrical diagnostic equipment, or portable lighting equipment are to be used shall be provided with GFCI protection for personnel. The GFCI protection device shall be located not less than 300 mm (12 in.) above the established electrical datum plane NEC Significant Code Changes Part 3 36

39 Article 690 Solar Photovoltaic (PV) Systems New Definitions. [Solar Photovoltaic (PV) Systems] A new definition for Functional Grounded PV System was added at This term is now used in six different locations throughout Article 690. According to this new definition, a functional grounded PV system is a PV system that has an electrical reference to ground that is not solidly grounded. An informational note added below the definition indicates that a functional grounded PV system is often connected to ground through a fuse, circuit breaker, resistance device, nonisolated grounded ac circuit, or electronic means that is part of a listed ground-fault protection system. This informational note goes on to inform users of the Code that conductors in these systems that are normally at ground potential may have voltage to ground during fault conditions. Functional Grounded PV System. A PV system that has an electrical reference to ground that is not solidly grounded. Informational Note: A functional grounded PV system is often connected to ground through a fuse, circuit breaker, resistance device, non-isolated grounded ac circuit, or electronic means that is part of a listed ground-fault protection system. Conductors in these systems that are normally at ground potential may have voltage to ground during fault conditions NEC Significant Code Changes Part 3 37

40 New Maximum Voltage [Solar Photovoltaic (PV) Systems] The requirements of pertain to maximum voltages of PV systems while relates to circuit sizing and maximum circuit current ratings of PV systems. Section went through an extensive revision in the 2017 NEC, simplifying these maximum voltage requirements and addressing the use of the terms related to maximum voltage and maximum current used throughout Article 690. The revised now has only three first level subdivisions: (A) Photovoltaic Source and Output Circuits [previous (A) Maximum Photovoltaic System Voltage and (C) Photovoltaic Source and Output Circuits combined together into one first level subdivision]; (B) DC-To-DC Converter Source and Output Circuits (a new section to address this equipment); and (C) Bipolar Source and Output Circuits Maximum Voltage [Solar Photovoltaic (PV) Systems] The maximum voltage of PV system dc circuits shall be the highest voltage between any two circuit conductors or any conductor and ground. PV system dc circuits on or in one- and two-family dwellings shall be permitted to have a maximum voltage of 600 volts or less. PV system dc circuits on or in other types of buildings shall be permitted to have a maximum voltage of 1000 volts or less. Where not located on or in buildings, listed dc PV equipment, rated at a maximum voltage of 1500 volts or less, shall not be required to comply with Parts II and III of Article 490. (A) Maximum Photovoltaic System Voltage Source and Output Circuits. Table 690.7(A) Voltage Correction Factors for Crystalline and Multi-Crystalline Silicon Modules (B) Direct-Current Utilization Circuits. (B) DC-to-DC Converter Source Output Circuits. (C) Photovoltaic Source and Output Circuits. (D) Circuits over 150 Volts to Ground. (E) (C) Bipolar Source and Output Circuits NEC Significant Code Changes Part 3 38

41 Revision/ New (A)(1) Circuit Sizing and Current. [Solar Photovoltaic (PV) Systems] In addition to the 125 percent method permitted by previous editions of the Code, a second option was added for calculating the maximum current for a PV source circuit using an industry standard method provided by a licensed professional electrical engineer. The 125 percent calculation method is fine for small systems as a simple calculation, but engineering supervision is now allowed for larger PV systems to use more accurate, less conservative calculations Circuit Sizing and Current. [Solar Photovoltaic (PV) Systems] (A) Calculation of Maximum Circuit Current. The maximum current for the specific circuit shall be calculated in accordance with 690.8(A) (1) through (A)(5) (6). Informational Note: Where the requirements of 690.8(A)(1) and (B)(1) are both applied, the resulting multiplication factor is 156 percent. (1)Photovoltaic Source Circuit Currents. The maximum current shall be the sum of parallel module rated short-circuit currents multiplied by 125 percent. calculated by one of the following methods: (1) The sum of parallel-connected PV module-rated short-circuit currents multiplied by 125 percent (2) For PV systems with a generating capacity of 100 kw or greater, a documented and stamped PV system design, using an industry standard method and provided by a licensed professional electrical engineer, shall be permitted. The calculated maximum current value shall be based on the highest 3-hour current average resulting from the simulated local irradiance on the PV array accounting for elevation and orientation. The current value used by this method shall not be less than 70 percent of the value calculated using 690.8(A)(1)(1). Informational Note: One industry standard method for calculating maximum current of a PV system is available from Sandia National Laboratories, reference SAND , Photovoltaic Array Performance Model. This model is used by the System Advisor Model simulation program provided by the National Renewable Energy Laboratory NEC Significant Code Changes Part 3 39

42 Revision/ New , Exception Arc-Fault Circuit Protection (Direct Current). [Solar Photovoltaic (PV) Systems] The requirement for PV AFCI protection at was revised by removing the previous subsections (2) and (3). A new exception allows PV AFCI protection to be omitted for PV systems that are not installed on or in buildings where the output circuits and dc-to-dc converter output circuits are direct buried, installed in metallic raceways, or installed in enclosed metallic cable trays Arc-Fault Circuit Protection (Direct Current). [Solar Photovoltaic (PV) Systems] Photovoltaic systems with dc source circuits, dc output circuits, or both, operating at a PV system maximum system voltage of 80 volts dc or greater, shall be protected by a listed (dc) PV arc-fault circuit interrupter, PV type, or other system components listed to provide equivalent protection. The PV arc-fault protection means shall comply with the following requirements: The system shall detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, module, or other system component in the dc PV system source and dc PV output circuits. (1) The system shall detect and interrupt arcing faults resulting from a failure in the intended continuity of a conductor, connection, module, or other system component in the dc PV source and dc PV output circuits. (2) The system shall require that the disabled or disconnected equipment be manually restarted. (3) The system shall have an annunciator that provides a visual indication that the circuit interrupter has operated. This indication shall not reset automatically. Informational Note: Annex A includes the reference for the Photovoltaic DC Arc-Fault Circuit Protection product standard. Exception: For PV systems not installed on or in buildings, PV output circuits and dc-to-dc converter output circuits that are direct buried, installed in metallic raceways, or installed in enclosed metallic cable trays are permitted without arc-fault circuit protection. Detached structures whose sole purpose is to house PV system equipment shall not be considered buildings according to this exception NEC Significant Code Changes Part 3 40

43 Revision/ New Rapid Shutdown of PV Systems on Buildings. [Solar Photovoltaic (PV) Systems] The rapid shutdown requirements of were revised to emphasize the primary purpose of the rapid shutdown requirements, which is to reduce shock hazard for emergency responders, and to answer questions regarding the functionality of the PV rapid shutdown device itself. The structure of is now subdivided into four separate subsections: (A) Controlled Conductors, (B) Controlled Limits, (C) Initiation Device, and (D) Equipment Rapid Shutdown of PV Systems on Buildings. [Solar Photovoltaic (PV) Systems] PV system circuits installed on or in buildings shall include a rapid shutdown function that controls specific conductors to reduce shock hazard for emergency responders in accordance with (1) (A)through(5)(D) as follows. Exception: Ground mounted PV system circuits that enter buildings, of which the sole purpose is to house PV system equipment, shall not be required to comply with (1) (A) Controlled Conductors. Requirements for controlled conductors shall apply only to PV circuits supplied by the PV system conductors of more than 1.5 m (5 ft) in length inside a building, or more than 3 m (10 ft) from a PV array. (B) Controlled Limits. The use of the term array boundary in this section is defined as 305 mm (1 ft) from the array in all directions. Controlled conductors outside the array boundary shall comply with (B)(1) and inside the array boundary shall comply with (B)(2). (2)(1) Outside the Array Boundary. Controlled conductors located outside the boundary or more than 1 m (3 ft) from the point of entry inside a building shall be limited to not more than 30 volts and 240 volt amperes within seconds of rapid shutdown initiation. (3) Voltage and power shall be measured between any two conductors and between any conductor and ground. (2) Inside the Array Boundary. The PV system shall comply with one of the following: (1) The PV array shall be listed or field labeled as a rapid shutdown PV array. Such a PV array shall be installed and used in accordance with the instructions included with the rapid shutdown PV array listing or field labeling. Informational Note: A listed or field labeled rapid shutdown PV array is evaluated as an assembly or system as defined in the installation instructions to reduce but not eliminate risk of 2017 NEC Significant Code Changes Part 3 41

44 electric shock hazard within a damaged PV array during fire-fighting procedures. These rapid shutdown PV arrays are designed to reduce shock hazards by methods such as limiting access to energized components, reducing the voltage difference between energized components, limiting the electric current that might flow in an electrical circuit involving personnel with increased resistance of the conductive circuit, or by a combination of such methods. (2) Controlled conductors located inside the boundary or not more than 1 m (3 ft) from the point of penetration of the surface of the building shall be limited to not more than 80 volts within 30 seconds of rapid shutdown initiation. Voltage shall be measured between any two conductors and between any conductor and ground. (3) PV arrays with no exposed wiring methods, no exposed conductive parts, and installed more than 2.5 m (8 ft) from exposed grounded conductive parts or ground shall not be required to comply with (B)(2). The requirement of (B)(2) shall become effective January 1, (C) Initiation Device. The initiation device(s) shall initiate the rapid shutdown function of all the PV system. The device off position shall indicate that the rapid shutdown function has been initiated for all PV systems connected to that device. For one-family and two-family dwellings, an initiation device(s) shall be located at a readily accessible location outside the building. (4) The rapid shutdown initiation methods shall be labeled in accordance with (B). The rapid shutdown initiation device(s) shall consist of at least one of the following: (1) Service disconnecting means (2) PV system disconnecting means (3) Readily accessible switch that plainly indicates whether it is in the off or on position Informational Note: One example of why an initiation device that complies with (C)(3) would be used is where a PV system is connected to an optional standby system that remains energized upon loss of utility voltage. Where multiple PV systems are installed with rapid shutdown functions on a single service, the initiation device(s) shall consist of not more than six switches or six sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, or in a group of separate enclosures. These initiation device(s) shall initiate the rapid shutdown of all PV systems with rapid shutdown functions on that service. Where auxiliary initiation devices are installed, these auxiliary devices shall control all PV systems with rapid shutdown functions on that service. (5)(D) Equipment. Equipment that performs the rapid shutdown functions, other than initiation devices such as listed disconnect switches, circuit breakers, or control switches, shall be listed and identified for providing rapid shutdown protection. Informational Note: Inverter input circuit conductors often remain energized for up to 5 minutes with inverters not listed for rapid shutdown NEC Significant Code Changes Part 3 42

45 Revision/ New Photovoltaic System Disconnecting Means. [Solar Photovoltaic (PV) Systems] For the 2017 NEC, (A) was revised by removing the nearest the point of entrance language and the accompanying exception. This PV disconnecting means must meet the provisions of for rapid shutdown and full compliance with this rule would satisfy the previous provisions of (A). The previous requirement of no PV disconnecting means located in bathrooms has been moved to the general requirements of 690.4(E) as it pertains to both equipment and disconnecting means. The requirement at (B) for marking or identifying of PV disconnecting means has been expanded for the 2017 NEC. Previous marking requirements at (B) did not give any specific details as to these marking provisions. Instead, these details were provided at (E) and These marking requirements have been moved to one location in (B) for this Code cycle Building or Other Structure Supplied by a Photovoltaic System Disconnecting Means. [Solar Photovoltaic (PV) Systems] Means shall be provided to disconnect all ungrounded dc conductors of a the PV system from all other conductors in a building or other structure wiring systems including power systems, energy storage systems, and utilization equipment and its associated premises wiring. (A) Location. The PV system disconnecting means shall be installed at a readily accessible location either on the outside of a building or structure or inside nearest the point of entrance of the system conductors. Exception: Installations that comply with (F) shall be permitted to have the disconnecting means located remote from the point of entry of the system conductors. The PV system disconnecting means shall not be installed in bathrooms. Informational Note: PV systems installed in accordance with address the concerns related to energized conductors entering a building. (B) Marking. Each PV system disconnecting means shall plainly indicate whether in the open (off) or closed (on) position and be permanently marked PV SYSTEM DISCONNECT or equivalent to identify it as a PV system disconnect. Additional markings shall be permitted based upon the specific system configuration. For PV system disconnecting means where the 2017 NEC Significant Code Changes Part 3 43

46 line and load terminals may be energized in the open position, the device shall be marked with the following words or equivalent: WARNING ELECTRIC SHOCK HAZARD TERMINALS ON THE LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION The warning sign(s) or label(s) shall comply with (B). (C) Suitable for Use. Each If the PV system is connected to the supply side of the service disconnecting means as permitted in (6), the PV system disconnecting means shall not be required to be listed as suitable for use as service equipment. (D) Maximum Number of Disconnects. The Each PV system disconnecting means shall consist of not more than six switches or six sets of circuit breakers, or a combination of not more than six switches and sets of circuit breakers, mounted in a single enclosure, or in a group of separate enclosures. A single PV system disconnecting means shall be permitted for the combined ac output of one or more inverters or ac modules in an interactive system. Informational Note: This requirement does not limit the number of PV systems connected to a service as permitted in 690.4(D). This requirement allows up to six disconnecting means to disconnect a single PV system. For PV systems where all power is converted through interactive inverters, a dedicated circuit breaker, in (D)(1), is an example of a single PV system disconnecting means. (E) Grouping. The PV system disconnecting means shall be grouped with other disconnecting means for the system in accordance with (D). A PV disconnecting means shall not be required at the PV module or array location. (E) Ratings. The PV system disconnecting means shall have ratings sufficient for the maximum circuit current available short-circuit current, and voltage that is available at the terminals of the PV system disconnect. (F) Type of Disconnect. (1) Simultaneous Disconnection. The PV system disconnecting means shall simultaneously disconnect the PV system conductors of the circuit from all conductors of other wiring systems. The PV system disconnecting means shall be an externally operable general-use switch or circuit breaker, or other approved means. A dc PV system disconnecting means shall be marked for use in PV systems or be suitable for backfeed operation. (2) Devices Marked Line and Load. Devices marked with line and load shall not be permitted for backfeed or reverse current. (3) DC-Rated Enclosed Switches, Open-Type Switches, and Low-Voltage Power Circuit Breakers. DC-rated, enclosed switches, open-type switches, and low-voltage power circuit breakers shall be permitted for backfeed operation NEC Significant Code Changes Part 3 44

47 Revision and Deletion (C)(1) (Wiring) Methods Permitted. [Solar Photovoltaic (PV) Systems] The term listed and labeled was replaced with listed and identified when describing singleconductor PV wire. The cable reel will have the listing label from the manufacturer, but this may not be available during an inspection process whereas the identified marking is required to be visible on the PV cable at 1.0 m (40 in.) intervals. A new installation requirement and references to (B)(4)(b) and have been added to (C) (1) for PV wiring in a PV array. The exception requiring a PV wire installed in a readily accessible location within a PV array be installed in a raceway was removed (Wiring) Methods Permitted. [Solar Photovoltaic (PV) Systems] (C) Single-Conductor Cable. (1) General. Single-conductor cable Type USE-2 and single-conductor cable listed and labeledidentified as photovoltaic (PV) wire shall be permitted in exposed outdoor locations in PV source circuits for PV module interconnections within the PV array. PV wire shall be installed in accordance with (B)(4)(b) and Exception: Raceways shall be used when required by (A) NEC Significant Code Changes Part 3 45

48 Deletion Ungrounded Photovoltaic Power Systems grounded PV systems and all other PV systems. For the 2017 NEC, these requirements for an ungrounded photovoltaic (PV) power system have been deleted, as the issues and topics previously covered at are addressed in other locations within Article 690. There is no longer any need to distinguish between the wiring methods of ungrounded systems, and what is now defined as a functional grounded PV system (see new definition at 690.2). The only distinction needed is between a solidly Ungrounded Photovoltaic Power Systems. Photovoltaic power systems shall be permitted to operate with ungrounded PV source and output circuits where the system complies with (A) through (G). (A) Disconnects. (B) Overcurrent Protection. (C) Ground-Fault Protection. (D) Conductors. (E) Battery Systems. (F) Marking. (G) Equipment NEC Significant Code Changes Part 3 46

49 Revision & Relocation System Grounding. [Solar Photovoltaic (PV) Systems] The provisions of were revised to properly address the methods by which PV systems are grounded. Two new first level subdivisions were added to (A) addresses PV System Grounding Configurations, while (B) covers Ground- Fault Protection for PV systems. To cap off this revision, the former text of was relocated to (B) to concur with the revised grounding requirements for PV systems System Grounding. [Solar Photovoltaic (PV) Systems] (A) PV System Grounding Configurations. One or more of the following system grounding configurations shall be employed: Photovoltaic systems shall comply with one of the following: (1) Ungrounded systems shall comply with wire PV arrays with one functional grounded conductor (2) Grounded two-wire systems shall have one conductor grounded or be impedance grounded, and the system shall comply with Bipolar PV arrays according to 690.7(C) with a functional ground reference (center tap) (3) Grounded bipolar systems shall have the reference (center tap) conductor grounded or be impedance grounded, and the system shall comply with PV arrays not isolated from the grounded inverter output circuit (4) Other methods that accomplish equivalent system protection in accordance with 250.4(A) with equipment listed and identified for the use shall be permitted to be used. Ungrounded PV arrays (5) Solidly grounded PV arrays as permitted in (B) Exception (6) PV systems that use other methods that accomplish equivalent system protection in accordance with 250.4(A) with equipment listed and identified for the use (B) Ground-Fault Protection. Grounded dc PV arrays shall be provided with dc ground-fault protection meeting the requirements of (B) (1) and (2) to reduce fire hazards. (was 690.5) Exception: Ground-mounted or pole-mounted PV arrays with not more than two paralleled source circuits and with all dc source and dc output circuits isolated from buildings shall be 2017 NEC Significant Code Changes Part 3 47

50 permitted without ground-fault protection. PV arrays with not more than two PV source circuits and with all PV system dc circuits not on or in buildings shall be permitted without ground-fault protection where solidly grounded. (was Exception) (1) Ground-Fault Detection. The ground fault protection protective device or system shall be capable of detecting a detect ground fault(s) in the PV array dc current-carrying conductors and components, including any intentionally functional grounded conductors, and be listed for providing PV ground-fault protection. [was 690.5(A)(1) and (A)(4)] (2) Isolating Faulted Circuits. The faulted circuits shall be isolated by one of the following methods: (1) The ungrounded current-carrying conductors of the faulted circuit shall be automatically disconnected. (2) The inverter or charge controller fed by the faulted circuit shall automatically cease to supply power to output circuits and isolate the PV system dc circuits from the ground reference in a functional grounded system. [was 690.5(B)(1) and (B)(2)] New/ Revision Grounding Electrode System. [Solar Photovoltaic (PV) Systems] but not required. For the 2017 NEC, the requirements for the installation of grounding electrodes and grounding electrode conductors have been greatly simplified, while maintaining the safety of PV systems. The provisions of former (A), (B), and (C) have been abridged and incorporated into the new (A). The provisions of former (D) [now (B)] pertaining to additional auxiliary electrodes for PV array grounding have been revised to clarify that these auxiliary electrodes are permitted Grounding Electrode System. [Solar Photovoltaic (PV) Systems] (A) Alternating-Current Systems. (B) Direct-Current Systems. (C) Systems with Alternating-Current and Direct-Current Grounding Requirements NEC Significant Code Changes Part 3 48

51 (A) Buildings or Structures Supporting a PV Array. A building or structure supporting a PV array shall have a grounding electrode system installed in accordance with Part III of Article 250. PV array equipment grounding conductors shall be connected to the grounding electrode system of the building or structure supporting the PV array in accordance with Part VII of Article 250. This connection shall be in addition to any other equipment grounding conductor requirements in (C). The PV array equipment grounding conductors shall be sized in accordance with For PV systems that are not solidly grounded, the equipment grounding conductor for the output of the PV system, connected to associated distribution equipment, shall be permitted to be the connection to ground for ground-fault protection and equipment grounding of the PV array. For solidly grounded PV systems, as permitted in (A)(5), the grounded conductor shall be connected to a grounding electrode system by means of a grounding electrode conductor sized in accordance with Informational Note: Most PV systems installed in the past decade are functional grounded systems rather than solidly grounded systems as defined in this Code. For functional grounded PV systems with an interactive inverter output, the ac equipment grounding conductor is connected to associated grounded ac distribution equipment. This connection is often the connection to ground for ground-fault protection and equipment grounding of the PV array. (B) (D) Additional Auxiliary Electrodes for Array Grounding. A Grounding electrodes shall be permitted to be installed in accordance with and at the location of all groundand pole-mounted PV arrays and as close as practicable to the location of roof-mounted PV arrays. The electrodes shall be permitted to be connected directly to the array frame(s) or structure. The dc grounding electrode conductor shall be sized according to Additional electrodes are not permitted to be used as a substitute for equipment bonding or equipment grounding conductor requirements. The structure of a ground- or pole-mounted PV array shall be permitted to be considered a grounding electrode if it meets the requirements of Roof-mounted PV arrays shall be permitted to use the metal frame of a building or structure if the requirements of (A)(2) are met NEC Significant Code Changes Part 3 49

52 New/ Revision (C) Identification of Power Sources Through an extensive revision process, (C) was divided into three list items: (C)(1) addresses rapid shutdown types; (C)(2) deals with buildings with more than one rapid shutdown type; and (C)(3) makes provisions for the rapid shutdown switch or rapid shutdown initiator (RSI). Two new figures were added in (C)(1) to illustrate new labels that are now required for the two different types of rapid shutdown systems for a PV installation. A detailed plan view diagram of the roof is required in certain situations by (C)(2) to provide illustrated guidance showing each different PV system and should include a dotted line around areas that remain energized after the rapid shutdown initiation switch is activated. The requirements of (C)(3) necessitate a rapid shutdown switch to have a label located directly on the RSI or no more than 1 m (3 ft) from the rapid shutdown switch that includes the words, RAPID SHUTDOWN SWITCH FOR SOLAR PV SYSTEM Identification of Power Sources. (A) Facilities with Stand-Alone Systems. Any structure or building with a PV power system that is not connected to a utility service source and is a stand-alone system shall have a permanent plaque or directory installed on the exterior of the building or structure at a readily visible location acceptable to the authority having jurisdiction. The plaque or directory shall indicate the location of system disconnecting means and that the structure contains a stand-alone electrical power system. The marking shall be in accordance with (G). (B) Facilities with Utility Services and PV Systems. Buildings or structures with both utility service and a PV system shall have a permanent plaque or directory providing the location of the service disconnecting means and the PV system disconnecting means if not located at the same location. The warning sign(s) or label(s) shall comply with (B). Plaques or directories shall be installed in accordance with (C) Facilities Buildings with Rapid Shutdown. Buildings or structures with both utility service and a PV system, complying with , shall have a permanent plaque or directory including the following wording: PHOTOVOLTAIC SYSTEM EQUIPPED WITH RAPID SHUTDOWN 2017 NEC Significant Code Changes Part 3 50

53 The plaque or directory shall be reflective, with all letters capitalized and having a minimum height of 9.5 mm (3/8 in.), in white on red background. Buildings with PV systems shall have permanent plaques or directories as described in (C)(1) through (C)(3). (1) Rapid Shutdown Type. The type of PV system rapid shutdown shall be labeled as described in (C)(1)(a) or (1)(b): (a)for PV systems that shut down the array and conductors leaving the array: SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN. TURN RAPID SHUTDOWN SWITCH TO THE OFF POSITION TO SHUT DOWN PV SYSTEM AND REDUCE SHOCK HAZARD IN ARRAY. The title SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUT DOWN shall utilize capitalized characters with a minimum height of 9.5 mm (3/8 in.) in black on yellow background, and the remaining characters shall be capitalized with a minimum height of 4.8 mm (3/16 in.) in black on white background. [See Figure (C)(1)(a).] (b) For PV systems that only shut down conductors leaving the array: SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN TURN RAPID SHUTDOWN SWITCH TO THE OFF POSITION TO SHUT DOWN CONDUCTORS OUTSIDE THE ARRAY. CONDUCTORS IN ARRAY REMAIN ENERGIZED IN SUNLIGHT. The title SOLAR PV SYSTEM IS EQUIPPED WITH RAPID SHUTDOWN shall utilize capitalized characters with a minimum height of 9.5 mm (3/8 in.) in white on red background, and the remaining characters shall be capitalized with a minimum height of 4.8 mm (3/16 in.) in black on white background. [See Figure (C)(1)(b).] Figure (C)(1)(a): Label for PV Systems that Shut Down the Array and the Conductors Leaving the Array. Figure (C)(1)(b): Label for PV Systems that Shut Down the Conductors Leaving the Array Only. The labels in (C)(1)(a) and (b) shall include a simple diagram of a building with a roof. The diagram shall have sections in red to signify sections of the PV system that are not shut down when the rapid shutdown switch is operated. The rapid shutdown label in (C)(1) shall be located on or no more than 1 m (3 ft) from the service disconnecting means to which the PV systems are connected and shall indicate the location of all identified rapid shutdown switches if not at the same location. (2) Buildings with More Than One Rapid Shutdown Type. For buildings that have PV systems with both rapid shutdown types or a PV system with a rapid shutdown type and a PV system with no rapid shutdown, a detailed plan view diagram of the roof shall be provided 2017 NEC Significant Code Changes Part 3 51

54 showing each different PV system and a dotted line around areas that remain energized after the rapid shutdown switch is operated. (3) Rapid Shutdown Switch. A rapid shutdown switch shall have a plaque or directory label located on or no more than 1 m (3 ft) from the service disconnecting means switch that includes the following wording: RAPID SHUTDOWN SWITCH FOR SOLAR PV SYSTEM The plaque or directory label shall be reflective, with all letters capitalized and having a minimum height of 9.5 mm (3/8 in.), in white on red background NEC Significant Code Changes Part 3 52

55 New/ Deletion - Article 690, Part VII Revisions to Part VII of Article 690 remove the content of Part VII and replace it with one simple reference to Article 705 where all these interconnection requirements are located. Former , Load Disconnect, was found to have antiquated language and was no longer relevant to PV systems. The language was removed along with the remainder of the previous language at Part VII of Article 690. What remains at Part VII of Article 690 is one simple new sentence at which states, PV systems connected to other sources shall be installed in accordance with Parts I and II of Article 705. Part I of Article 705 covers general requirements for interconnected electric power production sources while Part II of Article 705 concerns requirement for utility-interactive inverters. Part VII. Connection to Other Sources [Solar Photovoltaic (PV) Systems] Load Disconnect. A load disconnect that has multiple sources of power shall disconnect all sources when in the off position Connection to Other Sources. PV systems connected to other sources shall be installed in accordance with Parts I and II of Article Identified Interactive Equipment. Only inverters and ac modules listed and identified as interactive shall be permitted in interactive systems Loss of Interactive System Power. An inverter or an ac module in an interactive solar PV system shall automatically de-energize its output to the connected electrical production and distribution network upon loss of voltage in that system and shall remain in that state until the electrical production and distribution network voltage has been restored. A normally interactive solar PV system shall be permitted to operate as a stand-alone system to supply loads that have been disconnected from electrical production and distribution network sources Unbalanced Interconnections. Unbalanced connections shall be in accordance with Point of Connection. Point of connection shall be in accordance with NEC Significant Code Changes Part 3 53

56 Revision & Relocation General. (Energy Storage Systems) [Solar Photovoltaic (PV) Systems] A new Article 706, Energy Storage System, has been introduced to the Code. This article applies to all permanently installed energy storage systems (ESS) operating at over 50 volts ac or 60 volts dc that may be stand-alone or interactive with other electric power production sources. In conjunction with this new article, the former provisions of for installation of PV storage battery systems have been relocated to Part III of Article Installation General. (Energy Storage Batteries Systems) [Solar Photovoltaic (PV) Systems] An energy storage system connected to a PV system shall be installed in accordance with Article 706. (A) General. Storage batteries in a solar photovoltaic system shall be installed in accordance with the provisions of Article 480. The interconnected battery cells shall be considered grounded where the photovoltaic power source is installed in accordance with (B) Dwellings. (C) Current Limiting. (D) Battery Nonconductive Cases and Conductive Racks. (E) Disconnection of Series Battery Circuits. (F) Battery Maintenance Disconnecting Means. (G) Battery Systems of More Than 48 Volts. (II) Disconnects and Overcurrent Protection NEC Significant Code Changes Part 3 54

57 Article 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility New - Article 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility A new Article 691 for Large-Scale Photovoltaic (PV) Electric Power Production Facility was added to the 2017 NEC. The article covers the installation of large-scale PV electric power production facilities operated for the sole purpose of providing electric supply to the utility transmission or distribution system with a generating capacity of no less than 5,000 kw. Facilities covered by this article have specific design and safety features unique to large-scale PV facilities. These large-scale PV systems are typically accessible only to qualified personnel rather than to the general public. Unlike smaller scale PV systems, largescale PV electric power production facilities are designed and operated similarly to traditional utility power generating plants. Unqualified individuals are not allowed to access the system for their own safety and for protection of the system, which is crucial to grid stability. Access to large-scale PV electric supply stations must be restricted by a fencing structure to ensure that systems are adequately protected from the general public. Article 691 Large-Scale Photovoltaic (PV) Electric Power Production Facility Scope. This article covers the installation of large-scale PV electric power production facilities with a generating capacity of no less than 5000 kw, and not under exclusive utility control. Informational Note No. 1: Facilities covered by this article have specific design and safety features unique to large-scale PV facilities and are operated for the sole purpose of providing electric supply to a system operated by a regulated utility for the transfer of electric energy. Informational Note No. 2: Section 90.2(B)(5) includes information about utility-owned properties not covered under this Code. For additional information on electric supply stations, see ANSI/IEEE C2-2012, National Electrical Safety Code Definitions. Electric Supply Stations. Locations containing the generating stations and substations, including their associated generator, storage battery, transformer, and switchgear areas NEC Significant Code Changes Part 3 55

58 Generating Capacity. The sum of parallel-connected inverter rated maximum continuous output power at 40 C in kilowatts (kw). Generating Station. A plant wherein electric energy is produced by conversion from some other form of energy (e.g., chemical, nuclear, solar, wind, mechanical, or hydraulic) by means of suitable apparatus Special Requirements for Large-Scale PV Electric Supply Stations. Large-scale PV electric supply stations shall be accessible only to authorized personnel and comply with the following: (1) Electrical circuits and equipment shall be maintained and operated only by qualified personnel. Informational Note: Refer to NFPA 70E-2015, Standard for Electrical Safety in the Workplace, for electrical safety requirements. (2) Access to PV electric supply stations is restricted by fencing or other adequate means in accordance with Field- applied hazard markings shall be applied in accordance with (B). (3) The connection between the PV electric supply station and the system operated by a utility for the transfer of electrical energy shall be through medium- or high-voltage switch gear, substation, switch yard, or similar methods whose sole purpose shall be to safely and effectively interconnect the two systems. (4) The electrical loads within the supply station are only used to power auxiliary equipment for the generation of the PV power. (5) Large-scale PV electric supply stations shall not be installed on buildings Equipment Approval. All Electrical equipment shall be approved for installation by one of the following: Listing and labeling Field labeling Where products complying with 691.5(1) or (2) are not available, by engineering review validating that the electrical equipment is tested to relevant standards or industry practice Engineered Design. Documentation of the electrical portion of the engineered design of the electric supply station shall be stamped and provided upon request of the AHJ. Additional stamped independent engineering report reports detailing compliance of the design with applicable electrical standards and industry practice shall be provided upon request of the AHJ. The independent engineer shall be a licensed professional electrical engineer retained by the system owner or installer. This documentation shall include details of conformance of the design with Article 690, and any alternative methods to Article 690, or other articles of this Code Conformance of Construction to Engineered Design. Documentation that the construction of the electric supply station conforms to the electrical engineered design shall be provided upon request of the AHJ. Additional stamped independent engineering reports detailing the construction conforms with this Code, applicable standards 2017 NEC Significant Code Changes Part 3 56

59 and industry practice shall be provided upon request of the AHJ. The independent engineer shall be a licensed professional electrical engineer retained by the system owner or installer. This documentation, where requested, shall be available prior to commercial operation of the station Direct Current Operating Voltage. For large-scale PV electric supply stations, calculations shall be included in the documentation required in Disconnection of Photovoltaic Equipment. Isolating devices shall be permitted to be more than 1.8 m (6 ft) from the equipment where written safety procedures and conditions of maintenance and supervision ensure that only qualified persons service the equipment. Buildings whose sole purpose is to house and protect supply station equipment shall not be required to comply with Arc-Fault Mitigation. PV systems that do not comply with the requirements of shall include details of fire mitigation plans to address dc arc-faults in the documentation required in Fence Grounding. PV systems that do not comply with the requirements of shall include details of fire mitigation plans to address dc arc-faults in the documentation required in NEC Significant Code Changes Part 3 57

60 Article 695 Fire Pumps 695.6(G) Power Wiring. (Fire Pumps) The text at 695.6(G) was changed from ground-fault protection of equipment shall not be permitted for fire pumps to ground-fault protection of equipment shall not be installed in any fire pump power circuit. Hopefully, this will be clear enough language to prevent anyone from applying GFP to a fire pump. The new terminology is extracted material from NFPA 20 (Standard for the Installation of Stationary Fire Pumps for Fire Protection) as indicated with the bracketed text at the end of the new language at 695.6(G) Power Wiring. (Fire Pumps) Power circuits and wiring methods shall comply with the requirements in 695.6(A) through (J), and as permitted in (A), Exception No. 4; , Exception No. 4; ; ; 240.4(A); and (G) Ground-Fault Protection of Equipment. Ground-fault protection of equipment shall not be permitted for fire pumps installed in any fire pump power circuit. [20: ] Surge Protection. (Fire Pumps) A new requirement was added to demanding a listed surge protection device (SPD) be installed in or on all fire pump controllers. SPD protection is being added for items such as critical operations data systems and industrial machinery. Joining these crucial operations needing SPD protection for the 2017 NEC will be fire pump controllers. The location and type of SPD is a design issue and remains with the designer and/or installer. The SPDs for fire pump controllers are required to be listed devices as already required by former (now 285.6) Surge Protection. (Fire Pumps) A listed surge protection device shall be installed in or on the fire pump controller NEC Significant Code Changes Part 3 58

61 CHAPTER 7: SPECIAL CONDITIONS Article 700 Emergency Systems New and Branch Circuit Emergency Lighting Transfer Switch A new section was added to Article 700 at titled, Branch Circuit Emergency Lighting Transfer Switch. This section permits emergency lighting loads supplied by branch circuits rated at not greater than 20 amperes to be transferred from the normal branch circuit to an emergency branch circuit using a listed branch circuit emergency lighting transfer switch. This addition will accommodate a new class of transfer switching devices intended for operation of individual branch circuits in an emergency lighting system. The product standard and the design requirements for these new devices can be found in UL 1008 (Transfer Switch Equipment) Definitions. (Emergency Systems) Branch Circuit Emergency Lighting Transfer Switch. A device connected on the load side of a branch circuit overcurrent protective device that transfers only emergency lighting loads from the normal supply to an emergency supply. Informational Note: See ANSI/UL 1008, Transfer Switch Equipment, for information covering branch circuit emergency lighting transfer switches Branch Circuit Emergency Lighting Transfer Switch. Emergency lighting loads supplied by branch circuits rated at not greater than 20 amperes shall be permitted to be transferred from the normal branch circuit to an emergency branch circuit using a listed branch circuit emergency lighting transfer switch. The mechanically held requirement of 700.5(C) shall not apply to listed branch circuit emergency lighting transfer switches NEC Significant Code Changes Part 3 59

62 New (F) Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power A new first level subdivision is titled, Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power was added at 700.3(F) calling for emergency systems that rely on a single alternate source of power to include a permanent switching means to connect a portable or temporary alternate source of power while the single alternate source of power is disabled for maintenance or repair. This permanent switching means must be available for the duration of the maintenance or repair. This new requirement comes with an exception with four conditions. No prescriptive requirements existed prior to this change Tests and Maintenance (F) Temporary Source of Power for Maintenance or Repair of the Alternate Source of Power. If the emergency system relies on a single alternate source of power, which will be disabled for maintenance or repair, the emergency system shall include permanent switching means to connect a portable or temporary alternate source of power, which shall be available for the duration of the maintenance or repair. The permanent switching means to connect a portable or temporary alternate source of power shall comply with the following: 1. Connection to the portable or temporary alternate source of power shall not require modification of the permanent system wiring. 2. Transfer of power between the normal power source and the emergency power source shall be in accordance with The connection point for the portable or temporary alternate source shall be marked with the phase rotation and system bonding requirements. 4. Mechanical or electrical interlocking shall prevent inadvertent interconnection of power sources. 5. The switching means shall include a contact point that shall annunciate at a location remote from the generator or at another facility monitoring system to indicate that the permanent emergency source is disconnected from the emergency system NEC Significant Code Changes Part 3 60

63 It shall be permissible to utilize manual switching to switch from the permanent source of power to the portable or temporary alternate source of power and to utilize the switching means for connection of a load bank. Informational Note: There are many possible methods to achieve the requirements of 700.3(F). See Figure 700.3(F) for one example. Figure 700.3(F) Exception: The permanent switching means to connect a portable or temporary alternate source of power, for the duration of the maintenance or repair, shall not be required where any of the following conditions exists: 1. All processes that rely on the emergency system source are capable of being disabled during maintenance or repair of the emergency source of power. 2. The building or structure is unoccupied and fire suppression systems are fully functional and do not require an alternate power source. 3. Other temporary means can be substituted for the emergency system. 4. A permanent alternate emergency source, such as, but not limited to, a second on-site standby generator or separate electric utility service connection, capable of supporting the emergency system, exists. ) 2017 NEC Significant Code Changes Part 3 61

64 New (E) Transfer Equipment (Emergency Systems) A new requirement was added at 700.5(E) that will now require the short-circuit current rating of the transfer equipment to be field marked on the exterior of the transfer equipment. This shortcircuit current rating will be based on the specific overcurrent protective device type and settings protecting the transfer equipment. This additional field marking on the transfer equipment was deemed necessary as a transfer switch of this nature is typically marked by the manufacturer with several different options resulting in numerous short-circuit current rating values. These manufacturer-marked short-circuit current rating values can vary based upon the overcurrent protective device type, ampere rating and settings. Without this new short-circuit current rating field marking, this can be confusing for the inspection community as it is not obvious which short-circuit current rating is being utilized. This new field marking of the short-circuit current rating value will be based on the specific type of overcurrent protective device, ampere rating, and installed settings, which are known factors for the designer and/or installer Transfer Equipment (Emergency Systems) (E) Documentation. The short-circuit current rating of the transfer equipment, based on the specific overcurrent protective device type and settings protecting the transfer equipment, shall be field marked on the exterior of the transfer equipment NEC Significant Code Changes Part 3 62

65 Revision/ New (A) Wiring, Emergency System The emergency system identification at (A) has been expanded to more than just boxes and enclosures. These requirements will now be mandated for exposed emergency system cables and raceway systems that might not be associated with junction boxes or enclosures. An example of this type of installation could be a metallic cable system daisychained from emergency luminaire to emergency luminaire without installing a junction box between luminaires. This process would leave the emergency system wiring method from luminaire to luminaire indistinguishable from the normal system. New provisions at (A)(2) will now require exposed emergency circuit or system cable or raceway systems to be permanently marked as a component of an emergency circuit or system, at intervals not to exceed 7.6 m (25 ft) where boxes or enclosures are not encountered Wiring, Emergency System. (A) Identification. Emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system by the following methods: (1) All boxes and enclosures (including transfer switches, generators, and power panels) for emergency circuits shall be permanently marked so they will be readily identified as a component of an emergency circuit or system. (2) Where boxes or enclosures are not encountered, exposed cable or raceway systems shall be permanently marked to be identified as a component of an emergency circuit or system, at intervals not to exceed 7.6 m (25 ft). Receptacles supplied from the emergency system shall have a distinctive color or marking on the receptacle cover plates or the receptacles NEC Significant Code Changes Part 3 63

66 Revision/ New (D) Wiring, Emergency System Fire protection provisions for emergency system feeders were expanded to also include health care occupancies where persons are not capable of selfpreservation and educational occupancies with more than 300 occupants (in addition to highrise buildings and those buildings with large occupancy loads). The text has been reformatted into a more user-friendly list format. This revision/addition at (D) will result in additional safety to enhance the safe evacuation of the occupants in the event of a fire emergency at all building occupancies that fall under the requirements of the revised (D). Many schools and health care facilities that are not high-rise buildings or 1000-person assembly occupancies will now have their emergency systems protected from a fire for a minimum of two hours Wiring, Emergency System. (D) Fire Protection. Emergency systems shall meet the additional requirements in (D)(1) through (D)(3) in assembly occupancies for not less than 1000 persons or in buildings above 23 m (75 ft) in height. the following occupancies: (1) Assembly occupancies for not less than 1000 persons (2) Buildings above 23 m (75 ft) in height. (3) Health care occupancies where persons are not capable of self preservation (4) Educational occupancies with more than 300 occupants 2017 NEC Significant Code Changes Part 3 64

67 Article 701 Legally Required Standby Systems Revision/ New (D) Signals. (Legally Required Standby Systems) Code language was added to allow the ground-fault sensor to be located at an alternate location for systems with multiple emergency sources connected to a paralleling bus. Language was added to allow the ground fault sensor to be located at an alternate location for systems with multiple emergency sources connected to a paralleling bus. For multiple emergency sources, ground fault sensing may be determined by zero sequence sensing, differential relaying of the paralleling bus in conjunction with residual ground fault sensing device of the feeders, or other equivalent means Signals. (Legally Required Standby Systems) Audible and visual signal devices shall be provided, where practicable, for the purposes described in 701.6(A), (B), (C), and (D). (D) Ground Fault. To indicate a ground fault in solidly grounded wye, legally required standby systems of more than 150 volts to ground and circuit-protective devices rated 1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the legally required standby source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located at or near the sensor location. For systems with multiple emergency sources connected to a paralleling bus, the ground fault sensor shall be permitted at an alternate location. Informational Note: For signals for generator sets, see NFPA , Standard for Emergency and Standby Power Systems NEC Significant Code Changes Part 3 65

68 Article 702 Optional Standby Systems New (C) Power Inlets Rated at 100 Amperes or Greater, for Portable Generators of sight of the power inlets. New language was added requiring optional standby equipment containing power inlets rated 100 amperes or more for the connection of a generator source to be listed for the intended use and be equipped with an interlocked disconnecting means. Two exceptions have been added after this new language to address instances where the inlet has been rated as a disconnecting means and for supervised industrial installations where permanent space has been identified for the portable generator to be located within line Outdoor Generator Sets. (Optional Standby Systems) (A) Permanently Installed Generators and Portable Generators Greater Than 15 kwand Permanently Installed Generators. (C) Power Inlets Rated at 100 Amperes or Greater, for Portable Generators. Equipment containing power inlets for the connection of a generator source shall be listed for the intended use. Systems with power inlets shall be equipped with an interlocked disconnecting means. Exception No. 1: If the inlet device is rated as a disconnecting means. Exception No. 2: Supervised industrial installations where permanent space is identified for the portable generator located within line of sight of the power inlets shall not be required to have interlocked disconnecting means nor inlets rated as disconnects NEC Significant Code Changes Part 3 66

69 Article 705 Interconnected Electric Power Production Sources New - Article 705, Part IV Microgrid Systems A new Part IV was added to Article 705 titled, Microgrid Systems. Microgrid systems are sometimes referred to as intentionally islanded systems and stand-alone systems. Microgrids are a way to add resiliency against loss of power in premises wiring systems. Microgrid systems are modern, localized, small-scale grids, contrary to the traditional, centralized electricity grid. Microgrids can disconnect from the centralized grid and operate autonomously, strengthen grid resilience, and help mitigate grid disturbances because they can continue operating while the main grid is down; and they can function as a grid resource for faster system response and recovery. They often use diesel generators and are installed by the community they serve System Operation. Microgrid systems shall be permitted to disconnect from the primary source of power or other interconnected electric power production sources and operate as a separate microgrid system Primary Power Source Connection. Connections to primary power sources that are external to the microgrid system shall comply with the requirements of Reconnection to Primary Power Source. Microgrid systems that reconnect to primary power sources shall be provided with the necessary equipment to establish a synchronous transition Microgrid Interconnect Devices (MID). Microgrid interconnect devices shall comply with the following: (1) Be required for any connection between a microgrid system and a primary power source (2) Be listed or field labeled for the application (3) Have sufficient number of overcurrent devices located to provide overcurrent protection from all sources Informational Note: MID functionality is often incorporated in an interactive or multimode inverter, energy storage system, or similar device identified for interactive operation NEC Significant Code Changes Part 3 67

70 Article 706 Energy Storage Systems New - Article 706 Energy Storage Systems A new Article 706 titled, Energy Storage Systems, was added to the NEC pertaining to all permanently installed energy storage systems (ESS). Article 706 applies to all permanently installed energy storage systems (ESS) that may be stand-alone or interactive with other electric power production sources. An ESS is defined as one or more components assembled together capable of storing energy for use at a future time. An ESS can include but is not limited to batteries, capacitors, and kinetic energy devices (e.g., flywheels and compressed air). These systems can have ac or dc output for utilization and can include inverters and converters to change stored energy into electrical energy. Part I. General Scope. This article applies to all permanently installed energy storage systems (ESS) operating at over 50 volts ac or 60 volts dc that may be stand-alone or interactive with other electric power production sources. Informational Note: The following standards are frequently referenced for the installation of energy storage systems: (1) NFPA , Standard on Stored Electrical Energy Emergency and Standby Systems (2) IEEE , Recommended Practice for Installation Design and Installation of Vented Lead-Acid Batteries for Stationary Applications (3) IEEE , Recommended Practice for Sizing Vented Lead-Acid Storage Batteries for Stationary Applications (4) IEEE , Recommended Practice for Installation and Maintenance of Nickel- Cadmium Batteries for Photovoltaic (PV) Systems (5) IEEE , Recommended Practice for Installation Design, and Installation of Valve- Regulated Lead-Acid Batteries for Stationary Applications (6) IEEE , Recommended Practice for Stationary Battery Electrolyte Spill Containment and Management 2017 NEC Significant Code Changes Part 3 68

71 (7) IEEE 1635/ASHRAE , Guide for the Ventilation and Thermal Management of Stationary Battery Installations Batteries for Stationary Applications (8) UL 810A, Electrochemical Capacitors (9) UL 1973, Batteries for Use in Light Electric Rail (LER) Applications and Stationary Applications (10) UL 1989, Standard for Standby Batteries (11) UL Subject 2436, Spill Containment for Stationary Lead Acid Battery Systems (12) UL Subject 9540, Safety of Energy Storage Systems and Equipment Definitions. Battery. Two or more cells connected together electrically in series, in parallel, or a combination of both to provide the required operating voltage and current levels. Cell. The basic electrochemical unit, characterized by an anode and a cathode, used to receive, store, and deliver electrical energy. Container. A vessel that holds the plates, electrolyte, and other elements of a single unit, comprised of one or more cells, in a battery. It can be referred to as a jar or case. Diversion Charge Controller. Equipment that regulates the charging process of an ESS by diverting power from energy storage to direct-current or alternating-current loads or to an interconnected utility service. Electrolyte. The medium that provides the ion transport mechanism between the positive and negative electrodes of a cell. Energy Storage System (ESS). One or more components assembled together capable of storing energy for use at a future time. ESS(s) can include but is not limited to batteries, capacitors, and kinetic energy devices (e.g., flywheels and compressed air). These systems can have ac or dc output for utilization and can include inverters and converters to change stored energy into electrical energy. Energy Storage System, Self-Contained. Energy storage systems where the components such as cells, batteries, or modules and any necessary controls, ventilation, illumination, fire suppression, or alarm systems are assembled, installed, and packaged into a singular energy storage container or unit. Informational Note: Self-contained systems will generally be manufactured by a single entity, tested and listed to safety standards relevant to the system, and readily connected on site to the electrical system and in the case of multiple systems to each other. Energy Storage System, Pre-Engineered of Matched Components. Energy storage systems that are not self-contained systems but instead are pre-engineered and field-assembled using separate components supplied as a system by a singular entity that are matched and intended to be assembled as an energy storage system at the system installation site. Informational Note: Pre-engineered systems of matched components for field assembly as a system will generally be designed by a single entity and comprised of components that are tested and listed separately or as an assembly NEC Significant Code Changes Part 3 69

72 Energy Storage System, Other. Energy storage systems that are not self-contained or preengineered systems of matched components but instead are composed of individual components assembled as a system. Informational Note: Other systems will generally be comprised of different components combined on site to create an ESS. Those components would generally be tested and listed to safety standards relevant to the application. Flow Battery. An energy storage component similar to a fuel cell that stores its active materials in the form of two electrolytes external to the reactor interface. When in use, the electrolytes are transferred between reactor and storage tanks. Informational Note: Two commercially available flow battery technologies are zinc bromine and vanadium redox, sometimes referred to as pumped electrolyte ESS. Intercell Connector. An electrically conductive bar or cable used to connect adjacent cells. Intertier Connector. In a battery system, an electrical conductor used to connect two cells on different tiers of the same rack or different shelves of the same rack. Inverter Input Circuit. Conductors between the inverter and the ESS in stand-alone and multimode inverter systems. Inverter Output Circuit. Conductors between the inverter and another electric power production source, such as a utility for an electrical production and distribution network. Inverter Utilization Output Circuit. Conductors between the multimode or standalone inverter and utilization equipment. Nominal Voltage (Battery or Cell). The value assigned to a cell or battery of a given voltage class for the purpose of convenient designation. The operating voltage of the cell or battery may vary above or below this value. Sealed Cell or Battery. A cell or battery that has no provision for the routine addition of water or electrolyte or for external measurement of electrolyte specific gravity. Informational Note: Some cells that are considered to be sealed under conditions of normal use, such as valve-regulated lead acid or some lithium cells, contain pressure relief valves. Terminal. That part of a cell, container, or battery to which an external connection is made (commonly identified as a post, pillar, pole, or terminal post) Other Articles. Wherever the requirements of other articles of this Code and Article 706 differ, the requirements of Article 706 shall apply. If the ESS is capable of being operated in parallel with a primary source(s) of electricity, the requirements in 705.6, , , , , , , , and Part IV of Article 705 shall apply System Classification. ESS shall be classified as one of the types described as follows: (1) ESS, self-contained Informational Note: Some self-contained systems may be listed NEC Significant Code Changes Part 3 70

73 (2) ESS, pre-engineered of matched components (3) ESS, other Equipment. Monitors, controls, switches, fuses, circuit breakers, power conversion systems, inverters and transformers, energy storage components, and other components of the energy storage system other than lead-acid batteries, shall be listed. Alternatively, self contained ESS shall be listed as a complete energy storage system Multiple Systems. Multiple ESSs shall be permitted to be installed in or on a single building or structure Disconnecting Means. (A) ESS Disconnecting Means. A disconnecting means shall be provided for all ungrounded conductors derived from an ESS. A disconnecting means shall be readily accessible and located within sight of the ESS. Informational Note: See (H) for information on the location of the overcurrent device for conductors. (B) Remote Actuation. Where controls to activate the disconnecting means of an ESS are not located within sight of the system, the disconnecting means shall be capable of being locked in the open position, in accordance with , and the location of the controls shall be field marked on the disconnecting means. (C) Busway. Where a dc busway system is installed, the disconnecting means shall be permitted to be incorporated into the busway. (D) Notification. The disconnecting means shall be legibly marked in the field. The marking shall meet the requirements of (B) and shall include the following: (1) Nominal ESS voltage (2) Maximum available short-circuit current derived from the ESS (3) The associated clearing time or arc duration based on the available short-circuit current from the ESS and associated overcurrent protective devices if applicable (4) Date the calculation was performed Exception: The labeling in 706.7(D)(1) through (D)(4) shall not be required if an arc flash label is applied in accordance with acceptable industry practice. Informational Note No. 1: Industry practices for equipment labeling are described in NFPA 70E- 2015, Standard for Electrical Safety in the Workplace. This standard provides specific criteria for developing arc-flash labels for equipment that provides nominal system voltage, incident energy levels, arc-flash boundaries, minimum required levels of personal protective equipment, and so forth. Informational Note No. 2: Battery equipment suppliers can provide information about short circuit current on any particular battery model NEC Significant Code Changes Part 3 71

74 (E) Partitions and Distance. Where energy storage system input and output terminals are more than 1.5 m (5 ft) from connected equipment, or where the circuits from these terminals pass through a wall or partition, the installation shall comply with the following: (1) A disconnecting means shall be provided at the energy storage system end of the circuit. Fused disconnecting means or circuit breakers shall be permitted to be used. (2) A second disconnecting means located at the connected equipment shall be installed where the disconnecting means required by 706.7(E)(1) is not within sight of the connected equipment. Informational Note No. 1: For remote disconnect controls in information technology equipment rooms, see Informational Note No. 2: For overcurrent protection of batteries, see (H). (3) Where fused disconnecting means are used, the line terminals of the disconnecting means shall be connected toward the energy storage system terminals. (4) Disconnecting means shall be permitted to be installed in energy storage system enclosures where explosive atmospheres can exist if listed for hazardous locations. (5) Where the disconnecting means in (1) is not within sight of the disconnecting means in (2), placards or directories shall be installed at the locations of all disconnecting means indicating the location of all other disconnecting means Connection to Other Energy Sources. Connection to other energy sources shall comply with the requirements of (A) Load Disconnect. A load disconnect that has multiple sources of power shall disconnect all energy sources when in the off position. (B) Identified Interactive Equipment. Only inverters and ac modules listed and identified as interactive shall be permitted on interactive systems. (C) Loss of Interactive System Power. Upon loss of primary source, an ESS with a utility interactive inverter shall comply with the requirements of (D) Unbalanced Interconnections. Unbalanced connections between an energy storage system and electric power production sources shall be in accordance with (E) Point of Connection. The point of connection between an energy storage system and electric power production sources shall be in accordance with Energy Storage System Locations. Battery locations shall conform to (A), (B), and (C). (A) Ventilation. Provisions appropriate to the energy storage technology shall be made for sufficient diffusion and ventilation of any possible gases from the storage device, if present, to prevent the accumulation of an explosive mixture. A pre-engineered or self-contained ESS shall be permitted to provide ventilation in accordance with the manufacturer s recommendations and listing for the system NEC Significant Code Changes Part 3 72

75 Informational Note No. 1: See NFPA , Fire Code, Chapter 52, for ventilation considerations for specific battery chemistries. Informational Note No. 2: Some storage technologies do not require ventilation. Informational Note No. 3: A source for design of ventilation of battery systems is IEEE /ASHRAE Guideline Guide for the Ventilation and Thermal Management of Batteries for Stationary Applications, and the UBC. Informational Note No. 4: Fire protection considerations are addressed in NFPA , Fire Code. (B) Guarding of Live Parts. Guarding of live parts shall comply with (C) Spaces About ESS Components. Spaces about the ESS shall comply with Working space shall be measured from the edge of the ESS modules, battery cabinets, racks, or trays. For battery racks, there shall be a minimum clearance of 25 mm (1 in.) between a cell container and any wall or structure on the side not requiring access for maintenance. ESS modules, battery cabinets, racks, or trays shall be permitted to contact adjacent walls or structures, provided that the battery shelf has a free air space for not less than 90 percent of its length. Preengineered and self-contained ESSs shall be permitted to have working space between components within the system in accordance with the manufacturer s recommendations and listing of the system. Informational Note: Additional space is often needed to accommodate ESS equipment hoisting equipment, tray removal, or spill containment. (D) Egress. A personnel door(s) intended for entrance to and egress from rooms designated as ESS rooms shall open in the direction of egress and shall be equipped with listed panic hardware. (E) Illumination. Illumination shall be provided for working spaces associated with ESS and their equipment and components. Luminaires shall not be controlled by automatic means only. Additional luminaires shall not be required where the work space is illuminated by an adjacent light source. The location of luminaires shall not do either of the following: (1) Expose personnel to energized system components while performing maintenance on the luminaires in the system space (2) Create a hazard to the system or system components upon failure of the luminaire Directory. ESS shall be indicated by (A) and (B). The markings or labels shall be in accordance with (B). (A) Directory. A permanent plaque or directory denoting all electric power sources on or in the premises shall be installed at each service equipment location and at locations of all electric power production sources capable of being interconnected. Exception: Installations with large numbers of power production sources shall be permitted to be designated by groups. (B) Facilities with Stand-Alone Systems. Any structure or building with an ESS that is not connected to a utility service source and is a stand-alone system shall have a permanent plaque or directory installed on the exterior of the building or structure at a readily visible location 2017 NEC Significant Code Changes Part 3 73

76 acceptable to the authority having jurisdiction. The plaque or directory shall indicate the location of system disconnecting means and that the structure contains a stand-alone electrical power system. Part II. Circuit Requirements Circuit Sizing and Current. (A) Maximum Rated Current for a Specific Circuit. The maximum current for the specific circuit shall be calculated in accordance with (A)(1) through (A)(5). (1) Nameplate-Rated Circuit Current. The nameplate(s)- rated circuit current shall be the rated current indicated on the ESS nameplate(s) or system listing for pre-engineered or self contained systems of matched components intended for field assembly as a system. (2) Inverter Output Circuit Current. The maximum current shall be the inverter continuous output current rating. (3) Inverter Input Circuit Current. The maximum current shall be the continuous inverter input current rating when the inverter is producing rated power at the lowest input voltage. (4) Inverter Utilization Output Circuit Current. The maximum current shall be the continuous inverter output current rating when the inverter is producing rated power at the lowest input voltage. (5) DC to DC Converter Output Current. The maximum current shall be the dc-to-dc converter continuous output current rating. (B) Conductor Ampacity and Overcurrent Device Ratings. The ampacity of the feeder circuit conductors from the ESS(s) to the wiring system serving the loads to be serviced by the system shall not be less than the greater of the (1) nameplate(s) rated circuit current as determined in accordance with (A) or (2) the rating of the ESS(s) overcurrent protective device(s). (C) Ampacity of Grounded or Neutral Conductor. If the output of a single-phase, 2-wire ESS output(s) is connected to the grounded or neutral conductor and a single ungrounded conductor of a 3-wire system or of a 3-phase, 4-wire, wye connected system, the maximum unbalanced neutral load current plus the ESS(s) output rating shall not exceed the ampacity of the grounded or neutral conductor Overcurrent Protection. (A) Circuits and Equipment. ESS circuit conductors shall be protected in accordance with the requirements of Article 240. Protection devices for ESS circuits shall be in accordance with the requirements of (B) through (F). Circuits shall be protected at the source from overcurrent. (B) Overcurrent Device Ampere Ratings. Overcurrent protective devices, where required, shall be rated in accordance with Article 240 and the rating provided on systems serving the ESS and shall be not less than 125 percent of the maximum currents calculated in (A). (C) Direct Current Rating. Overcurrent protective devices, either fuses or circuit breakers, used in any dc portion of an ESS shall be listed and for dc and shall have the appropriate voltage, current, and interrupting ratings for the application NEC Significant Code Changes Part 3 74

77 (D) Current Limiting. A listed and labeled current-limiting overcurrent protective device shall be installed adjacent to the ESS for each dc output circuit. Exception: Where current-limiting overcurrent protection is provided for the dc output circuits of a listed ESS, additional current-limiting overcurrent devices shall not be required. (E) Fuses. Means shall be provided to disconnect any fuses associated with ESS equipment and components when the fuse is energized from both directions and is accessible to other than qualified persons. Switches, pullouts, or similar devices that are rated for the application shall be permitted to serve as a means to disconnect fuses from all sources of supply. (F) Location. Where ESS input and output terminals are more than 1.5 m (5 ft) from connected equipment, or where the circuits from these terminals pass through a wall or partition, overcurrent protection shall be provided at the ESS Charge Control. (A) General. Provisions shall be provided to control the charging process of the ESS. All adjustable means for control of the charging process shall be accessible only to qualified persons. Informational Note: Certain types of energy storage equipment such as valve-regulated lead acid or nickel cadmium can experience thermal failure when overcharged. (B) Diversion Charge Controller. (1) Sole Means of Regulating Charging. An ESS employing a diversion charge controller as the sole means of regulating charging shall be equipped with a second independent means to prevent overcharging of the storage device. (2) Circuits with Diversion Charge Controller and Diversion Load. Circuits containing a diversion charge controller and a diversion load shall comply with the following: (1) The current rating of the diversion load shall be less than or equal to the current rating of the diversion load charge controller. The voltage rating of the diversion load shall be greater than the maximum ESS voltage. The power rating of the diversion load shall be at least 150 percent of the power rating of the charging source. (2) The conductor ampacity and the rating of the overcurrent device for this circuit shall be at least 150 percent of the maximum current rating of the diversion charge controller. (3) Energy Storage Systems Using Utility-Interactive Inverters. Systems using utilityinteractive inverters to control energy storage state-of-charge by diverting excess power into the utility system shall comply with (B)(3)(a) and (B)(3)(b). (a) These systems shall not be required to comply with (B)(2). (b) These systems shall have a second, independent means of controlling the ESS charging process for use when the utility is not present or when the primary charge controller fails or is disabled. (C) Charge Controllers and DC-to-DC Converters. Where charge controllers and other DC-to-DC power converters that increase or decrease the output current or output voltage with respect to the input current or input voltage are installed, all of the following shall apply: 2017 NEC Significant Code Changes Part 3 75

78 (1) The ampacity of the conductors in output circuits shall be based on the maximum rated continuous output current of the charge controller or converter for the selected output voltage range. (2) The voltage rating of the output circuits shall be based on the maximum voltage output of the charge controller or converter for the selected output voltage range. Part III. Electrochemical Energy Storage Systems Part III of this article applies to ESSs that are comprised of sealed and non-sealed cells or batteries or system modules that are comprised of multiple sealed cells or batteries that are not components within a listed product. Informational Note: An energy storage component, such as batteries, that are integrated into a larger piece of listed equipment, such as an uninterruptible power supply (UPS), are examples of components within a listed product Installation of Batteries. (A) Dwelling Units. An ESS for dwelling units shall not exceed 100 volts between conductors or to ground. Exception: Where live parts are not accessible during routine ESS maintenance, an ESS voltage exceeding 100 volts shall be permitted. (B) Disconnection of Series Battery Circuits. Battery circuits subject to field servicing, where exceeding 240 volts nominal between conductors or to ground, shall have provisions to disconnect the series-connected strings into segments not exceeding 240 volts nominal for maintenance by qualified persons. Non load-break bolted or plug-in disconnects shall be permitted. (C) Storage System Maintenance Disconnecting Means. ESS exceeding 100 volts between conductors or to ground shall have a disconnecting means, accessible only to qualified persons, that disconnects ungrounded and grounded circuit conductor(s) in the electrical storage system for maintenance. This disconnecting means shall not disconnect the grounded circuit conductor(s) for the remainder of any other electrical system. A non load-break-rated switch shall be permitted to be used as a disconnecting means. (D) Storage Systems of More Than 100 Volts. On ESS exceeding 100 volts between the conductors or to ground, the battery circuits shall be permitted to operate with ungrounded conductors, provided a ground-fault detector and indicator is installed to monitor for ground faults within the storage system Battery and Cell Terminations. (A) Corrosion Prevention. Antioxidant material suitable for the battery connection shall be used when recommended by the battery or cell manufacturer. Informational Note: The battery manufacturer s installation and instruction manual can be used for guidance for acceptable materials. (B) Intercell and Intertier Conductors and Connections. The ampacity of field-assembled intercell and intertier connectors and conductors shall be of such cross-sectional area that the temperature rise under maximum load conditions and at maximum ambient temperature shall 2017 NEC Significant Code Changes Part 3 76

79 not exceed the safe operating temperature of the conductor insulation or of the material of the conductor supports. Informational Note: Conductors sized to prevent a voltage drop exceeding 3 percent of maximum anticipated load, and where the maximum total voltage drop to the furthest point of connection does not exceed 5 percent, may not be appropriate for all battery applications. IEEE , Guide for the Protection of Stationary Battery Systems, provides guidance for overcurrent protection and associated cable sizing. (C) Battery Terminals. Electrical connections to the battery and the cable(s) between cells on separate levels or racks shall not put mechanical strain on the battery terminals. Terminal plates shall be used where practicable Battery Interconnections. Flexible cables, as identified in Article 400, in sizes 2/0 AWG and larger shall be permitted within the battery enclosure from battery terminals to a nearby junction box where they shall be connected to an approved wiring method. Flexible battery cables shall also be permitted between batteries and cells within the battery enclosure. Such cables shall be listed and identified as moisture resistant. Flexible, fine-stranded cables shall only be used with terminals, lugs, devices, or connectors in accordance with Accessibility. The terminals of all cells or multicell units shall be readily accessible for readings, inspection, and cleaning where required by the equipment design. One side of transparent battery containers shall be readily accessible for inspection of the internal components Battery Locations. Battery locations shall conform to (A), (B), and (C). (A) Live Parts. Guarding of live parts shall comply with (B) Top Terminal Batteries. Where top terminal batteries are installed on tiered racks or on shelves of battery cabinets, working space in accordance with the storage equipment manufacturer s instructions shall be provided between the highest point on a storage system component and the row, shelf, or ceiling above that point. Informational Note: IEEE 1187 provides guidance for top clearance of VRLA batteries, which are the most commonly used battery in cabinets. (C) Gas Piping. Gas piping shall not be permitted in dedicated battery rooms. Part IV. Flow Battery Energy Storage Systems Part IV applies to ESSs composed of or containing flow batteries General. All electrical connections to and from the system and system components shall be in accordance with the applicable provisions of Article 692. The system and system components shall also meet the provisions of Parts I and II of this article. Unless otherwise directed by this article, flow battery ESS shall comply with the applicable provisions of Article NEC Significant Code Changes Part 3 77

80 Electrolyte Classification. The electrolyte(s) that are acceptable for use in the batteries associated with the ESS shall be identified by name and chemical composition. Such identification shall be provided by readily discernable signage adjacent to every location in the system where the electrolyte can be put into or taken out of the system Electrolyte Containment. Flow battery systems shall be provided with a means for electrolyte containment to prevent spills of electrolyte from the system. An alarm system shall be provided to signal an electrolyte leak from the system. Electrical wiring and connections shall be located and routed in a manner that mitigates the potential for exposure to electrolytes Flow Controls. Controls shall be provided to safely shut down the system in the event of electrolyte blockage Pumps and Other Fluid Handling Equipment. Pumps and other fluid handling equipment are to be rated/specified suitable for exposure to the electrolytes. Part V. Other Energy Storage Technologies The provisions of Part V apply to ESSs using other technologies intended to store energy and when there is a demand for electrical power to use the stored energy to generate the needed power General. All electrical connections to and from the system and system components shall be in accordance with the applicable provisions of this Code. Unless otherwise directed by this article, other energy storage technologies shall comply with the applicable provisions of Part III of Article NEC Significant Code Changes Part 3 78

81 Article 708 Critical Operations Power Systems (COPS) New (A)(2) Receptacle Identification In addition to the distinctive color or marking requirement for COPS receptacles, all nonlocking-type, 125-volt, 15- and 20-ampere receptacles supplied from the COPS are now required to have an illuminated face or an indicator light to indicate that there is power to the receptacle. This new illuminator or indicator light provision provides for ready and continuous ability to identify energized receptacles that are part of the COPS system. It is essential that nonlocking-type 125-volt, 15- and 20-ampere receptacles have either an indicator light or an illuminated face so that users of the receptacles know that they are energized in an emergency when not all receptacles are working Feeder and Branch Circuit Wiring. [Critical Operations Power Systems (COPS)] (A) Identification. (1) Boxes and Enclosures. In a building or at a structure where a critical operations power system and any other type of power system are present, all boxes and enclosures (including transfer switches, generators, and power panels) for critical operations power system circuits shall be permanently marked so they will be readily identified as a component of the critical operations power system. (2) Receptacle Identification. In a building in which COPS are present with other types of power systems described in other sections in this article, the cover plates for the receptacles or the receptacles themselves supplied from the COPS shall have a distinctive color or marking so as to be readily identifiable. Nonlocking-type, 125-volt, 15- and 20-ampere receptacles supplied from the COPS shall have an illuminated face or an indicator light to indicate that there is power to the receptacle. Exception: If the COPS supplies power to a DCOA that is a stand-alone building, receptacle cover plates or the receptacles themselves shall not be required to have distinctive marking NEC Significant Code Changes Part 3 79

82 Article 710 Stand-Alone Systems New - Article 710 Stand-Alone Systems Article 710, Stand-Alone Systems, was added to the 2017 NEC. As indicated in its scope, the article covers electric power production sources operating in a stand-alone mode. A stand-alone power system, sometimes referred to as a remote area power supply, is an off-thegrid system for locations that are not connected to an electricity distribution system. Stand-alone power systems will typically include one or more methods of electricity generation, energy storage, and regulation Scope. This article covers electric power production sources operating in stand-alone mode Equipment Approval. All equipment shall be listed and labeled or field labeled for the intended use General. Premises wiring systems shall be adequate to meet the requirements of this Code for similar installations supplied by a feeder or service. The wiring on the supply side of the building or structure disconnecting means shall comply with the requirements of this Code, except as modified by (A) through (F). (A) Supply Output. Power supply to premises wiring systems shall be permitted to have less capacity than the calculated load. The capacity of the stand-alone supply shall be equal to or greater than the load posed by the largest single utilization equipment connected to the system. Calculated general lighting loads shall not be considered as a single load. (B) Sizing and Protection. The circuit conductors between a stand-alone source and a building or structure disconnecting means shall be sized based on the sum of the output ratings of the stand-alone sources. (C) Single 120-Volt Supply. Stand-alone systems shall be permitted to supply 120 volts to single-phase, 3-wire, 120/240- volt service equipment or distribution panels where there are no 240-volt outlets and where there are no multiwire branch circuits. In all installations, the sum of the ratings of the power 2017 NEC Significant Code Changes Part 3 80

83 sources shall be less than the rating of the neutral bus in the service equipment. This equipment shall be marked with the following words or equivalent: WARNING: SINGLE 120-VOLT SUPPLY. DO NOT CONNECT MULTIWIRE BRANCH CIRCUITS! (D) Energy Storage or Backup Power System Requirements. Energy storage or backup power supplies are not required. (E) Back-Fed Circuit Breakers. Plug-in type back-fed circuit breakers connected to an interconnected supply shall be secured in accordance with (D). Circuit breakers marked line and load shall not be back-fed. (F) Voltage and Frequency Control. The stand-alone supply shall be controlled so that voltage and frequency remain within suitable limits for the connected loads NEC Significant Code Changes Part 3 81

84 Article 712 Direct Current Microgrids New - Article 712 Direct Current Microgrids A new Article 712 has been developed for direct current (dc) microgrids. A dc microgrid is defined as a power distribution system consisting of more than one interconnected dc power sources, supplying dc dc converters(s), dc loads(s), and/or ac loads(s) powered by dc ac inverters(s). A dc microgrid is typically not directly connected to an ac primary source of electricity, but some dc microgrids interconnect via one or more dc ac bidirectional converters or dc ac inverters. DC microgrids allow the direct utilization of power from dc sources to dc loads such as LED lighting, communications equipment, computers, variable-speed motor drives, etc. Direct utilization of dc, whether generated by PV systems, fuel cells or other means (without intervening dc ac and ac dc conversion steps) leads to higher efficiencies and potentially smaller and lower-cost equipment than ac-coupled methods. Part I. General Scope. This article applies to direct current microgrids Definitions. Direct Current Microgrid (DC Microgrid). A direct current microgrid is a power distribution system consisting of more than one interconnected dc power source, supplying dc-dc converter (s), dc load (s), and/or ac load (s) powered by dc-ac inverter (s). A dc microgrid is typically not directly connected to an ac primary source of electricity, but some dc microgrids interconnect via one or more dc-ac bidirectional converters or dc ac inverters. Informational Note: Direct current power sources include ac-dc converters (rectifiers), bidirectional dc-ac inverters/converters, photovoltaic systems, wind generators, energy storage systems (including batteries), and fuel cells. Grounded Two-Wire DC System. A system that has a solid connection or reference-ground between one of the current carrying conductors and the equipment grounding system. Grounded Three-Wire DC System. A system with a solid connection or reference-ground between the center point of a bipolar dc power source and the equipment grounding system NEC Significant Code Changes Part 3 82

85 Nominal Voltage. A value assigned to a circuit or system for the purpose of conveniently designating its dc voltage class. Informational Note: The actual voltage at which a circuit operates can vary from the nominal voltage within a range that permits satisfactory operation of equipment. Reference-Grounded DC System. A system that is not solidly grounded but has a lowresistance electrical reference that maintains voltage to ground in normal operation. Resistively Grounded. A system with a high- resistance connection between the current carrying conductors and the equipment grounding system. Primary DC Source. A source that supplies the majority of the dc load in a dc microgrid. Ungrounded DC System. A system that has no direct or resistive connection between the current carrying conductors and the equipment grounding system Other Articles. Wherever the requirements of other articles of this Code and Article 712 differ, the requirements of Article 712 shall apply. DC microgrids interconnected through an inverter or bidirectional converter with ac electric power production sources shall comply with Article Listing and Labeling. Any equipment used in the dc circuits of a direct-current micro grid shall be listed and labeled for dc use Directory. A permanent directory denoting all dc electric power sources operating to supply the dc microgrid shall be installed at each source location capable of acting as the primary dc source. Part II. Circuit Requirements Identification of Circuit Conductors (A) Ungrounded circuit conductors in dc microgrids shall be identified according to the requirements of 210.5(C)(2) for branch circuits and (C)(2) for feeders. (B) Ungrounded conductors of 6 AWG or smaller shall be permitted to be identified by polarity at all termination, connection, and splice points by marking tape, tagging, or other approved means System Voltage. The system voltage of a dc microgrid shall be determined by one of the following methods: (1) The nominal voltage to ground for solidly grounded systems (2) The nominal voltage to ground for reference-grounded systems (3) The highest nominal voltage between conductors for resistively grounded dc systems and ungrounded dc systems. Informational Note: Examples of nominal dc system voltages include but are not limited to 24, 48, 125, 190/380, or 380 volts. Part III. Disconnecting Means DC Source Disconnecting Means NEC Significant Code Changes Part 3 83

86 The output of each dc source shall have a readily accessible, disconnecting means that is lockable in the open position and adjacent to the source Disconnection of Ungrounded Conductors. In solidly grounded two- and three-wire systems, the disconnecting means shall simultaneously open all ungrounded conductors. In ungrounded, resistively grounded and reference-grounded systems, such devices shall open all current-carrying conductors Directional Current Devices. Disconnecting means shall be listed, be marked for use in a single current direction, and only be used in the designated current direction. Informational Note: Examples of directional current devices are magnetically quenched contactors and semiconductor switches in overcurrent devices. Part IV. Wiring Methods System Grounding. (A) General. Direct-current microgrids shall be grounded in accordance with (B) Over 300 Volts. DC microgrids operating at voltages greater than 300 volts dc shall be reference-grounded dc systems or resistively grounded dc systems Ground Fault Detection Equipment. Ungrounded, reference grounded, or resistively grounded dc microgrids operating at greater than 60 volts dc shall have ground fault detection that indicates that a fault has occurred. The ground fault equipment shall be marked in accordance with (C) Arc Fault Protection. Where required elsewhere in this Code, specific systems within the DC microgrid shall have arc fault protection. The arc fault protection equipment shall be listed. Informational Note: Section 90.4 applies when suitable equipment for arc fault protection is not available. Part V. Marking Distribution Equipment and Conductors. Distribution equipment and conductors shall be marked as required elsewhere in this Code Available DC Short-Circuit Current. (A) Field Marking. The maximum available dc short-circuit current on the dc microgrid shall be field marked at the dc source (s). The field marking(s) shall include the date the short-circuit current calculation was performed and be of sufficient durability to withstand the environment involved. (B) Modifications. When modifications to the electrical installation occur that affect the maximum available short-circuit current at the dc source, the maximum available short-circuit current shall be verified or recalculated as necessary to ensure the equipment ratings are sufficient for the maximum available short-circuit current at the line terminals of the 2017 NEC Significant Code Changes Part 3 84

87 equipment. The required field marking(s) in (A) shall indicate the new maximum available short-circuit current and date. Part VI. Protection Overcurrent Protection. Equipment and conductors connected to more than one electrical source shall have overcurrent protective devices to provide protection from all sources Interrupting and Short-Circuit Current Ratings. Consideration shall be given to the contribution of short-circuit currents from all interconnected power sources for the interrupting ratings and shortcircuit current ratings of equipment in the dc microgrid system (s). Overcurrent protective devices and equipment used within a dc microgrid shall have an interrupting rating at nominal circuit voltage or a shortcircuit current rating sufficient for the available short-circuit current at the line terminals of the equipment. Part VII. Systems over 1000 Volts General. Systems with a maximum voltage between conductors of over 1000 volts dc shall comply with Article 490 and other requirements in this Code applicable to installations rated over 1000 volts NEC Significant Code Changes Part 3 85

88 Article 725 Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits New (M) and (N) Other Articles (Class 1, Class 2, and Class 3 Remote- Control, Signaling, and Power-Limited Circuits) New 725.3(M) and (N) were added for Other Articles to provide guidance in the selection, listing and installation requirements for cable routing assemblies and communication raceways used for Class 2, Class 3 and PLTC cables. It provide consistency in the selection, listing and installation requirements for cable routing assemblies as referenced in Table (c), , (C) and It also provide consistency in the selection, listing and installation requirements of communications raceways with references to Table (b), , and through Other Articles (Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits) Circuits and equipment shall comply with the articles or sections listed in 725.3(A) through (L) (N). Only those sections of Article 300 referenced in this article shall apply to Class 1, Class 2, and Class 3 circuits. (M) Cable Routing Assemblies. Class 2, Class 3 and Type PLTC cables shall be permitted to be installed in plenum cable routing assemblies, riser cable routing assemblies, and generalpurpose cable routing assemblies selected in accordance with the provisions of Table (c), listed in accordance with the provisions of , and installed in accordance with the provisions of (C) and (N) Communications Raceways. Class 2, Class 3 and Type PLTC cables shall be permitted to be installed in plenum communications raceways, riser communications raceways and generalpurpose communications raceways selected in accordance with the provisions of Table (b), listed in accordance with the provisions of , and installed in accordance with the provisions of and through , where the requirements applicable to electrical nonmetallic tubing (ENT) apply NEC Significant Code Changes Part 3 86

89 Revision (K)(6), (L)(6) and (M)(6) Installation of Class 2, Class 3, and PLTC Cables New Code language was introduced at (K), (L), and (M) to clearly indicate that Type CMUC undercarpet communications wires and cables can be installed under modular flooring and planks, as well as under carpet Installation of Class 2, Class 3, and PLTC Cables. Installation of Class 2, Class 3, and PLTC cables shall comply with (A) through (M). (K) Other Building Locations. The following wires and cables shall be permitted to be installed in building locations other than the locations covered in (B) through (I): (See NEC text at (K)(1) through (6) for complete list of wiring methods) (6) Type CMUC undercarpet communications wires and cables installed under carpet, modular flooring, and planks (L) Multifamily Dwellings. The following wires and cables shall be permitted to be installed in multifamily dwellings in locations other than the locations covered in (B) through (I): (See NEC text at (L)(1) through (6) for complete list of wiring methods) (6) Type CMUC undercarpet communications wires and cables installed under carpet, modular flooring, and planks (M) One- and Two-Family Dwellings. The following wires and cables shall be permitted to be installed in one- and two-family dwellings in locations other than the locations covered in (B) through (I): (See NEC text at (M)(1) through (6) for complete list of wiring methods) (6) Type CMUC undercarpet communications wires and cables installed under carpet, modular flooring, and planks 2017 NEC Significant Code Changes Part 3 87

90 New , Table Transmission of Power and Data. (Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits) New provisions were added at and Table pertaining to remote powering over local area networking (LAN) cable. Additional information was introduced concerning new Type LP cable Transmission of Power and Data. (Class 1, Class 2, and Class 3 Remote- Control, Signaling, and Power-Limited Circuits) The requirements of (A) and (B) shall apply to Class 2 and Class 3 circuits that transmit power and data to a powered device. The requirements of Parts I and III of Article 725 and shall apply to Class 2 and Class 3 circuits that transmit power and data. The conductors that carry power for the data circuits shall be copper. The current in the power circuit shall not exceed the current limitation of the connectors. Informational No. 1: One example of the use of cables that transmit power and data is the connection of closed-circuit TV cameras (CCTV). Informational Note No. 2: The 8P8C connector is in widespread use with powered communications systems. These connectors are typically rated at 1.3 amperes maximum. Table Ampacities of Each Conductor in Amperes in 4-Pair Class 2 or Class 3 Data Cables Based on Copper Conductors at an Ambient Temperature of 30 C (86 F) with All Conductors in All Cables Carrying Current, 60 C (140 F), 75 C (167 F), and 90 C 2017 NEC Significant Code Changes Part 3 88

91 (194 F) Rated Cables (See NEC and illustration provided for complete text of Table ) (A) Use of Class 2 or Class 3 Cables to Transmit Power and Data. Where Types CL3P, CL2P, CL3R, CL2R, CL3, or CL2 transmit power and data, the following shall apply, as applicable: (1) The ampacity ratings in Table shall apply at an ambient temperature of 30 C (86 F). (2) For ambient temperatures above 30 C (86 F), the correction factors of (B)(2) shall apply. Informational Note: One example of the use of Class 2 cables is a network of closed- circuit TV cameras using 24 AWG, 60 C rated, Type CL2R, Category 5e local area network (LAN) cables. (B) Use of Class 2-LP or Class 3-LP Cables to Transmit Power and Data. Types CL3P-LP, CL2P-LP, CL3R-LP, CL2R-LP, CL3-LP, or CL2-LP shall be permitted to supply power to equipment at a current level up to the marked ampere limit located immediately following the suffix LP and shall be permitted to transmit data to the equipment. The Class 2-LP and Class 3-LP cables shall comply with the following, as applicable: Informational Note 1: The (xxa) following the suffix -LP indicates the ampacity of each conductor in a cable. Informational Note 2: An example of a limited power (LP) cable is a cable marked Type CL2- LP(0.5A), 23 AWG. A Type CL2-LP (0.5), 23 AWG could be used in any location where a Type CL2 could be used; however, the LP cable would be suitable for carrying up to 0.5 A per conductor, regardless of the number of cables in a bundle. If used in a 7-cable bundle, the same cable could carry up to 1.2 amperes per conductor. (1) Cables with the suffix -LP shall be permitted to be installed in bundles, raceways, cable trays, communications raceways, and cable routing assemblies. (2) Cables with the suffix -LP and a marked ampere level shall follow the substitution hierarchy of Table and Figure (A) for the cable type without the suffix LP and without the marked ampere level. (3) System design shall be permitted by qualified persons under engineering supervision NEC Significant Code Changes Part 3 89

92 Article 727 Instrumentation Type Cable: Type ITC 727.4(5) Ex. to (5) Uses Permitted. (Instrumentation Tray Cable: Type ITC) New for the 2017 NEC, an exception has been added for 727.4(5) permitting Type ITC-ER cable to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support (where not subject to physical damage). Under this new exception, this ITC cable must be mechanically supported where exiting the cable tray to ensure that the minimum bending radius is not exceeded Uses Permitted. (Instrumentation Tray Cable: Type ITC) Type ITC cable shall be permitted to be used as follows in industrial establishments where the conditions of maintenance and supervision ensure that only qualified persons service the installation: (1) In cable trays. (2) In raceways. (3) In hazardous locations as permitted in , , , , , , and (4) Enclosed in a smooth metallic sheath, continuous corrugated metallic sheath, or interlocking tape armor applied over the nonmetallic sheath in accordance with The cable shall be supported and secured at intervals not exceeding 1.8 m (6 ft). (5) Cable, without a metallic sheath or armor, that complies with the crush and impact requirements of Type MC cable and is identified for such use with the marking ITC-ER shall be permitted to be installed exposed. The cable shall be continuously supported and protected against physical damage using mechanical protection such as dedicated struts, angles, or channels. The cable shall be secured at intervals not exceeding 1.8 m (6 ft). Exception: Where not subject to physical damage, Type ITC-ER shall be permitted to transition between cable trays and between cable trays and utilization equipment or devices for a distance not to exceed 1.8 m (6 ft) without continuous support. The cable shall be mechanically supported where exiting the cable tray to ensure that the minimum bending radius is not exceeded. (6) As aerial cable on a messenger. (7) Direct buried where identified for the use. (8) Under raised floors in rooms containing industrial process control equipment and rack rooms where arranged to prevent damage to the cable. (9) Under raised floors in information technology equipment rooms in accordance with 645.5(E)(5)(b) NEC Significant Code Changes Part 3 90

93 Article 760 Fire Alarm Systems Revision (G) and (I) Listing and Marking of NPLFA Cables and Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors New temperature rating marking requirements were added for fire alarm circuits requiring the jacket of NPLFA and PLFA cables that have a temperature rating exceeding 60 C (140 F) to be marked with the appropriate temperature rating. The jacket of these fire alarm cables must also be marked with the conductor size as well. This required temperature rating information is important for both the installer and inspector as well as the system designer when utilizing power over Ethernet (PoE) and other technologies where the fire alarm cable pairs carry data and power. The conductor size in fire alarm cables is typically in the range of 22 to 26 AWG. When several of these fire alarm cables (as well as other cables) are bundled together in a draft-free, insulated space, dissipating the heat generated by the fire alarm circuit conductors can be an issue. Current levels on these fire alarm circuits continue to increase (in some cases as much as 1 ampere). To design, install, and inspect these systems, obtainable, detailed information concerning these fire alarm cables is essential. Part IV. Listing Requirements (Fire Alarm Systems) Listing and Marking of NPLFA Cables. Non-power-limited fire alarm cables installed as wiring within buildings shall be listed in accordance with (A) and (B) and as being resistant to the spread of fire in accordance with (C) through (F), and shall be marked in accordance with (G). Cable used in a wet location shall be listed for use in wet locations or have a moisture-impervious metal sheath. (G) NPLFA Cable Markings. Multiconductor non-power-limited fire alarm cables shall be marked in accordance with Table (G). Non power-limited fire alarm circuit cables shall be permitted to be marked with a maximum usage voltage rating of 150 volts. Cables that are listed for circuit integrity shall be identified with the suffix CI as defined in (F). Temperature rating shall be marked on the jacket of NPLFA cables that have a 2017 NEC Significant Code Changes Part 3 91

94 temperature rating exceeding 60 C (140 F). The jacket of NPLFA cables shall be marked with the conductor size. Informational Note: Cable types are listed in descending order of fire resistance rating Listing and Marking of PLFA Cables and Insulated Continuous Line-Type Fire Detectors. PLFA cables installed as wiring within buildings shall be listed as being resistant to the spread of fire and other criteria in accordance with (A) through (H) and shall be marked in accordance with (I). Insulated continuous line-type fire detectors shall be listed in accordance with (J). Cable used in a wet location shall be listed for use in wet locations or have a moisture-impervious metal sheath. (I) Cable Marking. The cable shall be marked in accordance with Table (I). The voltage rating shall not be marked on the cable. Cables that are listed for circuit integrity shall be identified with the suffix CI as defined in (G). Temperature rating shall be marked on the jacket of PLFA cables that have a temperature rating exceeding 60 C (140 F). The jacket of PLFA cables shall be marked with the conductor size. Informational Note: Voltage ratings on cables may be misinterpreted to suggest that the cables may be suitable for Class 1, electric light, and power applications. Exception: Voltage markings shall be permitted where the cable has multiple listings and voltage marking is required for one or more of the listings. Article 770 Optical Fiber Cables and Raceways New Overhead (Aerial) Optical Fiber Cables In previous editions of the Code, under the title of Cables Outside and Entering Buildings, Part II of Article 770 did not contain information about optical fiber cables installed overhead to a building or structure. That was rectified in the 2017 NEC with a new being added under Part II titled, Overhead (Aerial) Optical Fiber Cables. A section dealing with overhead outside plant optical fiber cables exists in Article 840 for premises-powered optical fiber-based broadband communications systems (see ), but was not previously included in Article 770 for optical fiber cables NEC Significant Code Changes Part 3 92

95 Overhead (Aerial) Optical Fiber Cables. Overhead optical fiber cables containing a non current-carrying metallic member entering buildings shall comply with (A) and (B). (A) On Poles and In-Span. Where outside plant optical fiber cables and electric light or power conductors are supported by the same pole or are run parallel to each other inspan, the conditions described in (A)(1) through (A)(4) shall be met. (1) Relative Location. Where practicable, the outside plant optical fiber cables shall be located below the electric light or power conductors. (2) Attachment to Cross-Arms. Attachment of outside plant optical fiber cables to a crossarm that carries electric light or power conductors shall not be permitted. (3) Climbing Space. The climbing space through outside plant optical fiber cables shall comply with the requirements of (D). (4) Clearance. Supply service drops and sets of overhead service conductors of 0 to 750 volts running above and parallel to optical fiber cable service drops shall have a minimum separation of 300 mm (12 in.) at any point in the span, including the point of their attachment to the building. Clearance of not less than 1.0 m (40 in.) shall be maintained between the two services at the pole. (B) Above Roofs. Outside plant optical fiber cables shall have a vertical clearance of not less than 2.5 m (8 ft) from all points of roofs above which they pass. Exception No. 1: The requirement of (B) shall not apply to auxiliary buildings such as garages and the like. Exception No. 2: A reduction in clearance above only the overhanging portion of the roof to not less than 450 mm (18 in.) shall be permitted if (a) not more than 1.2 m (4 ft) of optical fiber cable service drop cable passes above the roof overhang, and (b) the cable is terminated at a through- or above-the-roof raceway or approved support. Exception No. 3: Where the roof has a slope of not less than 100 mm in 300 mm (4 in. in 12 in.), a reduction in clearance to not less than 900 mm (3 ft) shall be permitted. Informational Note: For additional information regarding overhead wires and cables, see ANSI/IEEE C2-2012, National Electric Safety Code, Part 2, Safety Rules for Overhead Lines NEC Significant Code Changes Part 3 93

96 Revision (A) and (B) Optical Fiber Cables Entering Building spaces used for environmental air. The point of entrance is now permitted to be extended from the penetration of the external wall or floor slab by continuously enclosing the entrance optical fiber cables in RMC or IMC to the point of emergence. Code language was also added to clarify that unlisted nonconductive outside plant optical fiber cables installed in PVC or EMT cannot be installed in risers, ducts used for environmental air, plenums used for environmental air, and other Unlisted Cables and Raceways Entering Buildings. (Optical Fiber Cables and Raceways) (A) Conductive and Nonconductive Cables. Unlisted conductive and nonconductive outside plant optical fiber cables shall be permitted to be installed in building spaces, other than risers, ducts used for environmental air, plenums used for environmental air, and other spaces used for environmental air, where the length of the cable within the building, measured from its point of entrance, does not exceed 15 m (50 ft) and the cable enters the building from the outside and is terminated in an enclosure. The point of entrance shall be permitted to be extended from the penetration of the external wall or floor slab by continuously enclosing the entrance optical fiber cables in rigid metal conduit (RMC) or intermediate metal conduit (IMC) to the point of emergence. Informational Note No. 1: Splice cases or terminal boxes, both metallic and plastic types, typically are used as enclosures for splicing or terminating optical fiber cables. (B) Nonconductive Cables in Raceway. Unlisted nonconductive outside plant optical fiber cables shall be permitted to enter the building from the outside and shall be permitted to be installed in any of the following raceways: (1) Intermediate metal conduit (IMC) (2) Rigid metal conduit (RMC) (3) Rigid polyvinyl chloride conduit (PVC) (4) Electrical metallic tubing (EMT) Unlisted nonconductive outside plant cables installed in rigid polyvinyl chloride conduit (PVC) or electrical metallic tubing (EMT) shall not be permitted to be installed in risers, ducts used for 2017 NEC Significant Code Changes Part 3 94

97 environmental air, plenums used for environmental air, and other spaces used for environmental air. Revision Metallic Entrance Conduit Grounding The reference to RMC and IMC was removed and replaced with metallic conduit as all metallic conduits containing optical fiber entrance cables should require a bonding connection to a grounding electrode (not just RMC and IMC). Electrical metallic tubing (EMT) as permitted in (B)(4) should also be grounded and bonded for electrical safety. It should be noted that EMT is only permitted for use with nonconductive optical fiber cable as this cable contains no electrical conductive members and is not subject to the hazards associated with electrical power contact or lightning events. Conductive optical fiber cable, paired-conductor telephone cable (Article 800) and COAX cable (Article 820) contain metallic components and may be subject to power and lightning influences therefore they are limited to installation in the more robust RMC or IMC Metallic Entrance Conduit Grounding. (Optical Fiber Cables and Raceways) Rigid metal conduit (RMC) or intermediate metal conduit (IMC) Metallic conduit containing optical fiber entrance cable shall be connected by a bonding conductor or grounding electrode conductor to a grounding electrode in accordance with (B) NEC Significant Code Changes Part 3 95

98 (B)(3)(2) Lightning Protection Systems Conductors The term air terminal conductors (lightning-rod conductors) was replaced with the broader term lightning protection system conductors to clarify that no lightning protection system conductors should not be used as a part of the grounding electrode conductor or as a grounding electrode for optical fiber systems. For grounding and bonding and connection to a grounding electrode system for optical fiber cable systems, (B) offers provisions for three different applications; (1) In buildings or structures with an intersystem bonding termination (IBT), (2) In buildings or structures without an intersystem bonding termination, but with a grounding means, or (3) In buildings or structures without an intersystem bonding termination or grounding means. (D) Entrance Cable Bonding and Grounding. (Optical Fiber Cables and Raceways) Where required, the non current-carrying metallic members of optical fiber cables entering buildings shall be bonded or grounded as specified in (A) through (B) Electrode. The bonding conductor and grounding electrode conductor shall be connected in accordance with (B)(1), (B)(2), or (B)(3). (1) In Buildings or Structures with an Intersystem Bonding Termination. If the building or structure served has an intersystem bonding termination as required by , the bonding conductor shall be connected to the intersystem bonding termination. Informational Note: See Part I of Article 100 for the definition of Intersystem Bonding Termination. (2) In Buildings or Structures with Grounding Means. If an intersystem bonding termination is established, (A) shall apply. If the building or structure served has no intersystem bonding termination, the bonding conductor or grounding electrode conductor shall be connected to the nearest accessible location on one of the following: (1) The building or structure grounding electrode system as covered in (2) The grounded interior metal water piping system, within 1.5 m (5 ft) from its point of entrance to the building, as covered in NEC Significant Code Changes Part 3 96

99 (3) The power service accessible means external to enclosures using the options identified in (A), Exception as covered in (4) The nonflexible metallic power service raceway (5) The service equipment enclosure (6) The grounding electrode conductor or the grounding electrode conductor metal enclosure of the power service, or (7) The grounding electrode conductor or the grounding electrode of a building or structure disconnecting means that is grounded to an electrode as covered in (3) In Buildings or Structures Without Intersystem Bonding Termination or Grounding Means. If the building or structure served has no intersystem bonding termination or grounding means, as described in (B)(2), the grounding electrode conductor shall be connected to either of the following: (1) To any one of the individual grounding electrodes described in (A)(1), (A)(2), (A)(3), or (A)(4). (2) If the building or structure served has no grounding means, as described in (B)(2) or (B)(3)(1), to any one of the individual grounding electrodes described in (A)(7) and (A)(8) or to a ground rod or pipe not less than 1.5 m (5 ft) in length and 12.7 mm (1/2 in.) in diameter, driven, where practicable, into permanently damp earth and separated from lightning protection system conductors as covered in and at least 1.8 m (6 ft) from electrodes of other systems. Steam or hot water pipes or air terminal conductors (lightning-rod conductors) lightning protection system conductors shall not be employed as electrodes for non-current-carrying metallic members NEC Significant Code Changes Part 3 97

100 CHAPTER 8: COMMUNICATIONS SYSTEMS Article 810 Radio and Television Equipment Revision/ New Grounding of Radio and TV Equipment For the 2017 NEC, was revised to permit omission of grounding of masts and metal structures supporting radio and television antennas when the antenna and its related supporting mast or structure are within a zone of protection defined by a 46 m (150 ft) radius rolling sphere. A new informational note was also added to direct users of the Code to NFPA , Standard for the Installation of Lightning Protection Systems, for the application of the term rolling sphere Grounding. (Radio and Television Equipment) Masts and metal structures supporting antennas shall be grounded in accordance with unless the antenna and its related supporting mast or structure are within a zone of protection defined by a 46 m (150 ft) radius rolling sphere. Informational Note: See of NFPA , Standard for the Installation of Lightning Protection Systems, for the application of the term rolling sphere. Article 840 Premises-Powered Broadband Communications Systems Revision Network Terminals The scope of Article 840 now advises that the article covers premises-powered broadband communications systems that consist of an optical fiber, twisted pair, or coaxial cable to the premises supplying a broadband signal to a network terminal. The term Network Terminal is defined at and replaces the term, Optical Network Terminal (ONT) Definitions (Premises-Powered Broadband Communications Systems) Optical Network Terminal (ONT). A device that converts an optical signal network-provided signals (optical, electrical, or wireless) into component signals, including voice, audio, video, data, wireless, optical, and interactive service electrical services, and is considered to be a network interface equipment device on the premises that it is connected to a communications service provider and is powered at the premises NEC Significant Code Changes Part 3 98

101 Revision Unlisted Wires and Cables Entering Building Premises-powered broadband communications system wires and cables will now be required to comply with for unlisted optical fiber cables entering buildings, for unlisted communications wires and unlisted multipair communications cables entering buildings, and for unlisted coaxial cables entering buildings. Data and communications cabling installed in a building is typically required to be listed. Listing designations can be found throughout Articles 725, 770, 800, 820, and 830. Each article has listing requirements for such things as hazardous (classified) locations, mechanical execution of work, and the spread of fire or products of combustion and their intended use. Article 840 has references to these Articles 725, 770, 800, 820, and 830 listing references Unlisted Wires and Cables and Raceways Entering Buildings. (Premises-Powered Broadband Communications Systems) The requirements of shall apply Installations of unlisted cables entering buildings shall comply with (A), (B), or (C), as applicable. (A) Optical Fiber Cables. Installations of unlisted optical fiber cables entering buildings shall comply with (B) Communications Wires and Cables. Installations of unlisted communications wires and unlisted multipair communications cables entering buildings shall comply with (C) Coaxial Cables. Installations of unlisted coaxial cables entering buildings shall comply with NEC Significant Code Changes Part 3 99

102 Powering Circuits New requirements were added at giving permission for communication cables to carry circuits for powering communications equipment. This section goes on to indicate that where the power supplied over a communications cable is greater than 60 watts, communication cables and the power circuit must comply with new where communications cables are used in place of Class 2 and Class 3 cables. Part VI. Premises Powering of Communications Equipment over Communications Cables (Premises-Powered Broadband Communications Systems) Powering Circuits. Communications cables, in addition to carrying the communications circuit, shall also be permitted to carry circuits for powering communications equipment. Where the power supplied over a communications cable to communications equipment is greater than 60 watts, communication cables and the power circuit shall comply with where communications cables are used in place of Class 2 and Class 3 cables NEC Significant Code Changes Part 3 100

103 CHAPTER 9: TABLES AND ANNEX D Revision/ New - Chapter 9 Tables Chapter 9, Notes to Tables, Note 9 New text was added to Note 9 of the Chapter 9 tables to clearly specify that assemblies of single insulated conductors without an overall covering are not to be considered a cable when determining conduit or tubing fill area. The conduit or tubing fill for the assemblies is to be calculated based upon the individual conductors. Chapter 9 Tables Notes to Tables (9) A multiconductor cable, optical fiber cable, or flexible cord of two or more conductors shall be treated as a single conductor for calculating percentage conduit or tubing fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the ellipse as a circle diameter. Assemblies of single insulated conductors without an overall covering shall not be considered a cable when determining conduit or tubing fill area. The conduit or tubing fill for the assemblies shall be calculated based upon the individual conductors NEC Significant Code Changes Part 3 101

104 Revision - Informative Annex D Example D3 Store Building In previous editions of the Code, this example informs the user of the Code when determining the actual connected lighting load that 125% of the actual connected lighting load (8500 VA 1.25 = 10,625 VA) is less than 125% of the load from Table , so the minimum lighting load from Table is used in the calculation. For the 2017 NEC, this 125% for the actual connected lighting load has been removed. Informative Annex D, Example D3 A store 50 ft by 60 ft, or 3000 ft2, has 30 ft of show window. There are a total of 80 duplex receptacles. The service is 120/240 V, single phase 3-wire service. Actual connected lighting load is 8500 VA. *In the example, 125% of the actual connected lighting load (8500 VA 1.25 = 10,625 VA) is less than 125% of the load from Table , so the minimum lighting load from Table is used in the calculation. Had the actual lighting load been greater than the value calculated from Table , 125% of the actual connected lighting load would have been used. Minimum Size Feeder (or Service) Overcurrent Protection [see or ] 32,450 VA 240 V = 135 A The next higher standard size is 150 A (see 240.6) NEC Significant Code Changes Part 3 102

105 Revision - Informative Annex D, Example D7 Sizing of Service Conductors for Dwelling(s) Informative Annex Example D7 was revised to give two examples for sizing dwelling unit service conductors. The previous D7 is identified as an example with no required adjustment or correction factors, and a new example was added to illustrate the method used when temperature correction factors are involved. The new example calculates the size for dwelling unit service conductors with the allowed (B)(7) eighty-three percent adjustment along with a temperature correction factor from Table (B)(2)(a). Example D7 Sizing of Service Conductors for Dwelling(s) [see310.15(b)(7)] Service conductors and feeders for certain dwellings are permitted to be sized in accordance with (B)(7). With No Required Adjustment or Correction Factors If a 175-ampere service rating is selected, a service conductor is then sized as follows: 175 amperes 0.83 = amperes per (B)(7). If no other adjustments or corrections are required for the installation, then, in accordance with Table (B)(16), a 1/0 AWG Cu or a 3/0 AWG Al meets this rating at 75 C (167 F). With Required Temperature Correction Factor If a 175-ampere service rating is selected, a service conductor is then 175 amperes 0.83 = amperes per (B)(7). If the conductors are installed in an ambient temperature of 40 C (104 F), the conductor ampacity must be multiplied by the appropriate correction factor in Table (B)(2)(a). In this case, we will use an XHHW-2 conductor, so we use a correction factor of 0.91 to find the minimum conductor ampacity and size: x.91 = amperes In accordance with Table (B)(16), a 2/0 AWG CU or a 4/0 AWG AL would be required. If no temperature correction or ampacity adjustment factors are required, the following table includes conductor sizes calculated using the requirements in (B)(7). This table is based on 75 C terminations and without any adjustment or correction factors NEC Significant Code Changes Part 3 103

106 Revision/ New - -Informative Annex D, Example D8 Motor Circuit Conductors, Overload Protection, and Short-Circuit and Ground-Fault Protection Example D8 has been revised for the Feeder Short-Circuit and Ground-Fault Protection portion to show (a) an example using nontime delay fuse and (b) an example using inverse time circuit breaker. The feeder portion of Example D8 was divided into two categories: (a) an example using a non-time delay fuse and (b) an example using an inverse time circuit breaker. The previous text in the example might have led the user of the Code to think that the size of the short-circuit and ground-fault protective device of the feeder was always based upon the type of protective device that had been chosen for the largest protective device of the branch circuits fed by the feeder, plus the sum of the other motors. An additional example using different types of devices was needed and, therefore, added for this Code cycle. Example D8 Motor Circuit Conductors, Overload Protection, and Short- Circuit and Ground-Fault Protection (see 240.6, 430.6, , , , , , and , Table , and Table ) Determine the minimum required conductor ampacity, the motor overload protection, the branch-circuit short-circuit and ground-fault protection, and the feeder protection, for three induction-type motors on a 480-V, 3-phase feeder, as follows: (a) One 25-hp, 460-V, 3-phase, squirrel-cage motor, nameplate full-load current 32 A, Design B, Service Factor 1.15 (b) Two 30-hp, 460-V, 3-phase, wound-rotor motors, nameplate primary full-load current 38 A, nameplate secondary full-load current 65 A, 40 C rise. Feeder Short-Circuit and Ground-Fault Protection (a) Example Using Nontime Delay Fuse. The rating of the feeder protective device is based on the sum of the largest branch-circuit protective device (example is 110 A) for the specific type of device protecting the feeder: 300% 34 A = 102 A (therefore the next largest standard size, 110 A, would be used) plus the sum of the full-load currents of the other motors, or 110 A NEC Significant Code Changes Part 3 104

107 A + 40 A = 190 A. The nearest standard fuse that does not exceed this value is 175 A [see and (A)]. (b) Example Using Inverse Time Circuit Breaker. The largest branch-circuit protective device for the specific type of device protecting the feeder, 250% 34 A = 85 A. The next larger standard size is 90 A, plus the sum of the full-load currents of the other motors, or 90 A + 40 A + 40 A = 170 A. The nearest standard inverse time circuit breaker that does not exceed this value is 150 A [see and (A)] Access the Code The complete 2017 NEC can be accessed online for free at the following link. Be sure to select Free access to the 2017 edition of NFPA 70 Additional, the code can be purchased in both a book and pdf from the same link. Click on button below to view the quiz 2017 NEC Significant Code Changes Part 3 105