Combination Type AFCI Evolution of the Arc Fault Circuit Interrupter www.usa.siemens.com/afci 2
Alarming Statistics According to the U.S. Fire Administration (USFA), an estimated 67,800 fires, 485 deaths, and approximately 2,300 injuries occur each year that can be associated with home wiring totaling $868 million in property losses. a The CPSC estimates that AFCI devices currently on the market may address 50% or more of these fires. b The National Electric Code has responded to this identified problem by requiring the use of AFCIs beginning with the 1999 version of the NEC and continuing that focus on safety with a requirement from combination AFCI beginning January 1, 2008, according to the 2005 NEC. The issue is so significant that the U.S. CPSC and the National Association of State Fire Marshalls (NASFM) are promoting the use of AFCI protection in both new and existing homes. The Combination AFCI is the latest technology that provides maximum available protection against the effects of arcing faults. a On the Safety Circuit: A Fact Sheet on Home Electrical Fire Prevention United States Fire Administration (2006) b Oct.1, 2002 CPSC2NFPA Technical Committee Document Proposal Form What is a Combination AFCI? Let s begin with what a Combination AFCI is NOT. It is not a replacement for a Ground Fault Circuit Interrupter (GFCI). A GFCI is intended for personal protection and interrupts the circuit to the load when the ground fault current exceeds 6mA, but not when the ground fault current is 4mA or less. An AFCI is a device intended to mitigate the effects of arcing faults by functioning to de-energize the circuit when an arc-fault is detected. * These are very different functions for very different applications. Neither device can replace the need for the other. * UL 1699 Arc Fault Circuit Interrupters (Second Edition) The Branch/Feeder AFCI can only detect line-to-neutral and line-to-ground arcing faults, as illustrated above. A Combination Type AFCI detects all three types of arcing: line-to-neutral, line-to-ground, and series arcing. The Combination Type AFCI differs from the Branch/Feeder AFCI in its ability to detect series arcing faults. 3
What are the differences? Conventional circuit breakers have two tripping mechanisms The short circuit or magnetic trip (electromagnetic element) 4Occurs when two current-carrying conductors touch and a low resistance path for current between the conductors is created 4Results in a surge current that will quickly trip a standard circuit breaker Current Overload or thermal trip (bimetal element) 4Occurs when the rated capacity of the circuit breaker is exceeded because additional devices are added to a circuit or existing devices require additional current AFCIs have the same tripping mechanisms above PLUS Arcing fault trip (electronic) 4Results from brief, intermittent current flow between current-carrying conductors 4Sporadic and high-resistance in nature 4Results in low-level current surges that are unlikely to trip a conventional circuit breaker due to the sporadic characteristics 4
What is unique about the Siemens Combination Type AFCI? Siemens features unique trip indicators on each AFCI product, providing a valuable analysis tool to help electricians pinpoint the type of trip. These indicators are in the form of LEDs that appear near the handle of the breaker. The LED indications will appear for 5 seconds each time the AFCI is turned ON up to 30 days after the last trip. One LED will be illuminated if the last trip was a result of an arcing fault. On the 2-pole AFCI, the leg on which the arcing fault was detected can be determined based on which single LED was illuminated. Two LEDs (three LEDs on the 2-pole AFCI) will be illuminated if the last trip was a result of an arcing fault to ground. No indication will be displayed if the AFCI trips as a result of an overcurrent condition. This last known trip indication can also be cleared from memory to assist with verifying resolution of the problem. LED trip indicators 1-pole CAFCI LED indication guide LED indicator Last known trip condition LED (A) LED (B) OFF OFF Overcurrent ON OFF Arc Fault ON ON Arc Fault to ground 2-pole CAFCI LED indication guide Last known trip LED indicator condition Yellow 1 Yellow 2 Yellow 3 OFF OFF OFF Overcurrent ON OFF OFF Arc fault (Leg A) OFF OFF ON Arc fault (Leg B) ON ON ON Arc fault to ground 5
With a 160 year history of engineering and innovation, Siemens strives to develop products that provide increased levels of safety. The Combination Type AFCI is another example in which Siemens has used advanced technology to ensure fit, form, and function for customers. Both performance and reliability are ensured by the technology implemented. This technology has been thoroughly tested by third-party laboratories and in the field. Specifically, the advanced semiconductor technology utilizes proprietary components designed to detect and react to the unique characteristics of arcing while maintaining a high level of reliability. This reliability is ensured by detailed design and verified by extensive testing. 6
Intelli-Arc Diagnostic Tool Improves troubleshooting accuracy Reduces the number of visits to the problem site Can be used with any circuit breaker regardless of brand. Currently AFCI protection devices only monitor and protect branch circuits in the home against arc faults. Although the LEDs on the Siemens Combination Type AFCIs can help to point an electrician in the right direction for troubleshooting, these AFCIs do not help to pinpoint the portion of the branch circuit that contained the fault. Arc faults are often intermittent which can make troubleshooting the branch circuit very difficult. In these cases, it is important to determine whether the fault condition exists in the permanent wiring, in connected equipment, or in a power cord. Intelligent arc detection technology The Siemens Intelli-Arc Diagnostic Tool helps to accurately diagnose the circuit in which a fault has occurred. When used in conjunction with good troubleshooting techniques, this tool allows the electrical contractor to determine and locate the root cause or source of the fault. The Intelli-Arc Diagnostic Tool presents information as to the type and magnitude of fault. Since the fault may not cause an AFCI to trip for various reasons, i.e. duration too short, current level too low, the tool provides an indication showing how close an event is to causing an AFCI to trip. The goal of the diagnostic tool is to speed the troubleshooting process for the electrical contractor. The device drastically improves the accuracy of the troubleshooting process. This, in turn, will significantly reduce the number of visits to the problem site. Every intent of this device is directed as saving the electrical contractor time for each branch circuit that must be evaluated. The Intelli-Arc Diagnostic Tool can be used with any circuit breaker regardless of brand. Thoroughly tested AFCIs help to ensure the safety of those who will live, work, or play in the buildings by protecting them from hidden faults that can smolder for hours before breaking into the open in spectacular form. Few building trades do as much to protect the American public as electrical contractors, and AFCIs are important tools in the electrician s safety arsenal. 7
Intelli-Arc Diagnostic Tool Features Wireless communication Hook location for attaching base unit to the load center Amp indicator (A) Ground fault indicator (B) Power indicator Communication indicator with hand-held Arc fault indicator (C) Communication with base unit Clear (last event) Power button Push and hold "clear" button while pressing "power" button to test the hand-held functionality Wire terminals to load Hand-held unit Wire terminals to breaker Base unit Intelli-Arc Diagnostic Tool LED troubleshooting indications Three sets of LED indicators are provided on the hand-held device for use in troubleshooting branch circuit issues. These three indications give information regarding current ( AMPS ), ground fault level ( GF ), and arc fault level ( AF ). A.Current ( AMPS ) 1. The full scale current for this LED indication is 20+A 2. LED indicators do not increase by uniform intervals. 3. The 5A point is marked on hand-held device for reference. B.Ground Fault ( GF ) 1. The full scale current for this LED indication is 50+ ma. C. Arc Fault ( AF ) 1. This LED indication does not display in reference to current level but rather in severity of events, with a full scale reading (red LED) representing an event that is very likely to cause an AFCI device to trip. 2. Partial readings (yellow LEDs) should be evaluated. Combined independent events may cause an AFCI to trip. 3. Transitional events, i.e. turning on an appliance, are likely to register as some low level on the arc fault scale. 4.The action taken that produces the highest level of indication should be thoroughly evaluated for any issues that may be present. 2. LED indicators do not increase by uniform levels. 8
National Electrical Code Progression The need for AFCI has been established by various respected organizations. Requirements are already in place to mandate the use of the Combination Type AFCI. These Combination Type AFCIs provide the maximum protection available today for reducing the possibly catastrophic effects of arcing faults. 1999 NEC J Listed AFCI future requirement in Code - Allows Branch/Feeder AFCI J January 1, 2002: bedroom receptacles 2002 NEC J Listed AFCI in ALL bedroom circuits - Allows Branch/Feeder AFCI 2005 NEC J Combination Type AFCI in bedroom circuits J Branch/Feeder AFCI permitted until January 1, 2008 2008 NEC J Combination Type AFCI J Expand to 1 pole, 15220A circuits installed in family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, or similar rooms or areas Siemens Industry, Inc. Building Technologies Division 5400 Triangle Parkway Norcross, GA 30092 1-800-964-4114 info.us@siemens.com www.usa.siemens.com/afci Subject to change without prior notice Order No.: RPFL-COMBO-1009 All rights reserved Printed in USA 2009 Siemens Industry, Inc. The information provided in this brochure contains merely general descriptions or characteristics of performance which in case of actual use do not always apply as described or which may change as a result of further development of the products. An obligation to provide the respective characteristics shall only exist if expressly agreed in the terms of contract. All product designations may be trademarks or product names of Siemens AG or supplier companies whose use by third parties for their own purposes could violate the rights of the owners.