Safer Inspection of Medium Voltage Electrical Panels on Navy Ships

Transcription

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. 1 FY15 NSRP ETP Panel Project Safer Inspection of Medium Voltage Electrical Panels on Navy Ships NSRP ETP Panel Meeting All Panel Meeting, Charleston, SC March 12, 2015 Penn State Electro-Optics Center The Navy Manufacturing Technology Center of Excellence for Electro-Optics 222 Northpointe Blvd. Freeport, PA Jeff Callen Research and Development Engineer Electrical Engineering and Systems Engineering , ext jcallen@eoc.psu.edu Matthew E. DiGioia Engineering Project Manager Assistant to ManTech Program Operations , ext mdigioia@eoc.psu.edu

2 Presentation Outline 1. Project Background Issue & Approach Participants & Stakeholders Goals & Objectives 2. Issues & Status Technical Approach & Deliverables Project Assumptions & Requirements Milestones 3. Summary Quad / End 4. Backups Programmatics Technical Tasks Details NFPA 70E Assumptions & Requirements Talking Points (From Kickoff Meeting) Concerns & Risks Meeting & Reviews Master Integrated Schedule Other Solution Concepts (IR Fibers for Blackbody Radiation & Embedded Temp Sensor) Results of 2014 Trade Study 2

3 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Background Even under best practices, installation of shipboard switchboards results in loose connections and wiring mistakes that lead to arc faults and other electrical maladies Average of 8 arc faults per year throughout the navy fleet - all occurred in Switchboards and Load Centers - cost Navy millions of dollars in downtime and repairs [NAVSEA, Gulf Coast] Newer ships have electrical systems considered medium to high voltage LHD, LHA, DDG-51, DDG-1000 = Medium, 4160 volt systems (CVN = High, 13,000 volt systems) Switchboard Inspections: during construction, builder s trial, during sea trials, and again at regular maintenance intervals Current inspection methods: typically utilize Thermal IR imagers to investigate cabinets and comparatively identify hotspots ; other investigation modes require close proximity interrogation Shore Power Switchboard 3

4 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Lighting Distribution Box Gear / Motor Controller 4

5 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Issue Current Inspection Practices: secure the area, personnel don full coverage Personal Protective Equipment (PPE) to image inside active panels, preferably while drawing a high load such as during sea trials Necessitates a new paradigm in switchboard inspection to comply with OSHA regulations and avoid Technical Warrant Holder (TWH) waiver requests Approach EOC s initial analysis identified preliminary requirements and potential solutions for both temporary installations acceptable before and during sea trials as well as permanent solutions which must be compliant with Mil-Specs for shipboard operations Leading candidate solution: temporary or permanent installation of panel covers with IR transparent windows enabling safe IR inspection without exposing personnel to active electrical components This would allow inspectors in the room to operate at any time before/during acceptance/sea trials without PPE, while utilizing the same cameras and practices currently used but without the cumbersome and costly need to secure the area and deactivate and reactivate electrical switchboards. Besides IR windows, potential solutions with pros and cons of each were identified including a standalone gantry for remote imaging, temperature sensitive paint, and RF interrogation of embedded temperature sensors Candidate solutions were vetted through NSRP Electrical Technologies Panel (ETP) presentations and subsequent stakeholder interactions. With the support of this community, the approach was refined such that this project focuses on demonstration of temporary (or permanent) installation of panel covers with IR transparent windows enabling safe IR inspection without exposing personnel to energized electrical components 5

6 Active Project Participants Lead Investigators Jeff Callen Matthew E. DiGioia Sponsoring Shipyard Jason Farmer Penn State Electro-Optics Center Research and Development Engineer, Electrical Engineering and Systems Engineering Penn State Electro-Optics Center Engineering Project Manager, ManTech Sensors, Robotics, and Automation Ingalls Shipbuilding (Pascagoula) Project Lead / Electrical Engineer IV jcallen@eoc.psu.edu mdigioia@eoc.psu.edu jason.farmer@hii-ingalls.com Government Stakeholder Clay Smith Project Technical Representative Richard Deleo SUPSHIP Gulf Coast Engineering Newport News Shipbuilding Engineering Manager - Submarine Electrical david.smith@supshipgc.navy.mil r.deleo@hii-nns.com 6

7 Integrated Project Team (IPT): Advisors and Other Stakeholders Government Stakeholders Humberto Lopez Dave Mako Naval Sea Systems Command NAVSEA 05Z32 Electrical Distribution Systems, Office of the Technical Warrant Holder, The Naval Systems Engineering Directorate (SEA05) Naval Surface Warfare Center - Carderock Ship Systems Engr Station, NSWCCD-SSES C937 Humberto.Lopez@navy.mil Charles.mako@navy.mil Industry Advisors Dennis Neitzel Gary Weiss AVO Training Institute, Inc. OSHA Authorized Maritime Trainer Principal Committee Member, NFPA 70E DRS Power & Control Technologies, Inc. Business Development Manager for Power Distribution and Power Conversion Dennis.Neitzel@avotraining.com garypweiss@drs.com Other Interested Parties Greg Stevens Bath Iron Works Electrical Engineering Gregory.Stevens@gdbiw.com 7

8 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Project Goals and Objectives The suitability and the safety impact of using IR windows in electrical panels for thermographic inspection of electrical connections on Navy ships will be determined 1. Develop safer, cost effective solutions with IR transparent viewports in electrical panel covers to reduce risk for government and shipbuilder inspection of onboard medium/high voltage electrical infrastructures Facilitate comprehensive inspections accomplished with less risk and reduced labor Eliminate or reduce the need for secured locations, personal protective equipment (PPE), and waiver requests wrt OSHA standards 2. Develop and demonstrate a proof of concept solution that meets temporary (or permanent) installation requirements for the shipbuilder/government implementers Utilize principal methods and practices currently employed but without the cumbersome and costly need to secure the area and deactivate and reactivate electrical switchboards Inspections made with closed panels avoiding dangerous proximity to energized circuits Allow inspectors in the room to operate at any time before/during acceptance/sea trials 3. Establish the business / safety case and path to implementation for government and shipbuilder applications Develop the business case and risk reduction benefits for shipbuilder construction and government applications where inspection of electric switchboards, load centers, and transformers is necessary Pursue industry support and buy-in with identification of vendors which can provide products that meet temporary installation requirements Explore the criteria and viability for permanent installations within MIL-DTL (RevA pending) 8

9 Technical Approach Process and Means to Accomplishing Goals and Objectives (from SOW) 1. Review Shipbuilder/Government/Industry Requirements for IR Panel Inspection and Current Inspection Practices [HII, SSGC & Penn State EOC] 2. Determine Camera(s) and Window(s) to be Used [Penn State EOC Led] 3. Laboratory Tests of Cameras and Windows [Penn State EOC Led] 4. Devise Practical Implementation [Penn State EOC, HII & SSGC] 5. Plan and Prepare for Final Demonstration [Penn State EOC, HII & SSGC] 6. Develop Technology Transition Path Including Safety/Business Case [All] 9

10 Deliverables 6.1 Proof of Concept Demonstration (Targeting LHA-7 Sea Trial) A proof of concept demonstration will take place at the end of the project to show an IR thermographic inspection through a window on a closed cover of a representative electrical panel. Venue and test conditions to be determined during project in conjunction with stakeholders HII and SSGC. The demonstration is not meant to be comprehensive, i.e. will not cover all panel types and all geometries, but will be representative to the agreement of the stakeholders. Relevant demonstration data will be recorded and analyzed for inclusion and discussion in the final report. 6.2 Quarterly Reports: April, July, and October Reflect the Sample Status Report found in the NSRP Panel Project Guide and shall include the following sections: (1) Project Overview, (2) Technical Status, (3) Schedule, (4) Business Status, (5) Issues, (6) Near-Term Plans 6.3 Final Project Report Final report content shall summarize research done, test methodology, test results, demonstration results, and technology transition path forward 10

11 Project Assumptions (as of 2/19/17): V panel from LHA7 examined at HII on 2/11/15 will be considered as representative of the inspection to be solved. This type of panel will be used for the project demonstration. 2. Target conditions for final demonstration will be to take thermal images on one energized LHA7 panel in situ on the ship. Intentional faults will be excluded for safety reasons. Scheduling and logistical concerns may preclude this scenario and if so, alternative conditions will be developed and agreed upon by the IPT. 3. While all electrical connections within the cabinet are important for inspection, SUPSHIPS is most interested in the connections made at the shipyard to the cabinet. Specifically, this includes the feed cables at the bottom level of the cabinet and at the middle level of the cabinet. The connections to the fuses at middle and top and the transformers behind the fuses will be considered but with lower priority than the feed cables. 4. Broadband windows will be required such that IR and visible inspection can be completed through the same viewing port. 5. IR windows used will have metal covers over them to secure the integrity of the panel cover when window is not in use. 6. HII and GCSS will be able to loan IR cameras for thermal inspection to Penn State EOC subject to scheduling constraints. 7. Depending on viewing angle and cabinet construction, multiple smaller windows may be desirable rather than fewer large windows. 8. Windows and other materials used in the testing and demonstration will need to meet MIL-STD 901D Grade B shock and vibration, or that a path forward to attain this standard can be developed. 9. Field of View and off angle viewing will permit much more area within the cabinet to be viewed by the camera than the space directly behind the window. 11

12 Project Requirements (as of 2/19/17): 1. Relevant delta temperature values for pass/fail inspection of 4160V panels or guidelines as to what temperature delta will make a relevant demonstration. 2. Dimensional drawings of the target demonstration panel, so realistic laboratory tests can be developed. 3. Samples or part numbers of dust cover boots used in the target 4160 panel. If not available, then representative material. 4. Samples of cables with lugs that are used for connecting to the target 4160 panel. 5. List of IR thermography cameras currently used or planned to be used for inspections (Fluke TI-32, FLIR EX320) 6. If possible, supply of an actual panel cover for the target 4160V cabinet that can be modified for installation of IR windows to use in the demonstration. 12

13 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Summary Milestones 1/19/15: Contract awarded to EOC 2/11/15: Kickoff Meeting HII 1. 4/10/15: Quarterly Report #1 2. 4/16/15 (Thur): 1st Telecon (review requirements & camera selections, Quarterly Report #1) 3. ~6/18/15: Technology Interchange Meeting (Concurrent with Summer ETP Meeting) Discuss the results of initial research into suitable IR inspection window(s) and camera(s) Identify a candidate system for testing and demonstration with preliminary test plans conveyed The outcome of this meeting will be agreement to proceed with procuring equipment & materials 4. Jul 2015: Quarterly Report #2 5. Aug 2015: 2nd Telecon (review finalized lab experiments & plans) 6. Oct 2015: Quarterly Report #3 7. Oct 2015: Technology Interchange EOC (was 3rd Telecon ) Review lab results and discuss practical implementation plans 8. Dec 2015: 4th Telecon (review plans for final demo) 9. Jan 2016: Draft of Final Report Delivered (1 Week before Final Review) 10. Jan 2016: Final Review Meeting & Handoff Concept Design (@ SUPSHIP GC) [Deliverable] 11. Jan 2016: Update & Deliver Final Report with Transition Path Developed [Deliverable] 12. 1/20/16: End of EOC Period of Performance 13

14 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Sponsor: The National Shipbuilding Research Program 2014 Electrical Technologies Panel Project Average of 8 arc faults per year throughout the navy fleet - all occurred in Switchboards and Load Centers - cost Navy millions of dollars in downtime and repairs. Current Inspection Practices: secure the area, personnel don full coverage Personal Protective Equipment to image inside active panels, preferably while drawing a high load such as during sea trials. Tasks/Achievements: Review Shipbuilder/Government/Industry Requirements for IR Panel Inspection and Current Inspection Practices Leverage the current state of the art in industry and the recently revised NFPA 70E criteria (National Electrical Code, Standard for Electrical Safety in the Workplace ); emphasizes substantial risk reduction for workplace injuries and fatalities due to shock, electrocution, arc flash, and arc blast Laboratory Experimentation with Cameras and Windows Plan and Execute Final Demonstration of Practical / Representative scenario on a Navy ship Develop Technology Transition Path Including Safety/Business Case Deliverables: Proof of Concept Demonstration: representative IR thermographic inspection using an IR window in closed electrical panel cover of a Quarterly Reports: April, July, and October Final Project Report: Jan-16 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Objective: Develop safer, cost effective solution within existing thermographic inspection practices for onboard medium/high voltage electrical infrastructures: utilize IR transparent viewports in electrical panel covers to reduce risk for government and shipbuilders Performing Activities: Jan 2015 Jan 2016, $150K Penn State Electro-Optics Center Ingalls Shipbuilding SUPSHIP Gulf Coast Newport News Shipbuilding Integrated Product Team Includes: NAVSEA (TWH Office), Naval Surface Warfare Center Carderock, OSHA Safety Trainer, Industry Product Supplier Implementation: System: Medium & High Voltage Electrical Infrastructures on Navy Platforms (LHD, LHA, CVN ) Site: LHA-7 SUPSHIP-GC (Proof of Concept Demo) Schedule: Jan 2016 = Demo Results with Transition Plan for Temporary Installations Status: Intend future Insertion / adoption Benefits / Payoff: Reduced safety risk to personnel: enables safer practices within existing inspection methods and procedures Potential to provide inspection process cost savings Applicable across multiple military domains & platforms with Information shareable across shipbuilder industry 14 RevA Nov14

15 BACKUPS (From Kickoff Meeting) 15

16 Technical Tasks Process and Means to Accomplishing Goals and Objectives 1. Review Shipbuilder/Government/Industry Requirements for IR Panel Inspection and Current Inspection Practices [HII, SSGC & Penn State EOC - SOW 5.2] Leverage the current state of the art in industry and the revised NFPA 70E criteria (National Electrical Code, Standard for Electrical Safety in the Workplace ) Review and convey the current practices for electrical panel inspection with IR thermography, including equipment used, procedures, techniques, and numerical expectations for pass/fail [HII, SSGC] Review techniques and procedures with perspective of NFPA 70E Standard for Electrical Safety in the Workplace against industry/government requirements for panel inspection [Penn State EOC led with IPT support] Review and verify that the planned path forward will allow panel inspections without PPE and OSHA waivers [Penn State EOC led with IPT support] (Continued on Next Slide) 16

17 Technical Tasks (Continued) 2. Determine Camera(s) and Window(s) to be Used [Penn State EOC Led - SOW 5.3] Borrow hardware from HII and SSGC; provide IR camera/systems and panel covers which are representative of electrical inspection practices Seek rentals, loaners, in-kind equipment from industry (cameras and elec. cabinet suppliers) ($4K budgeted) Purchase sample material/windows and miscellaneous supplies for test and demo ($4K budgeted) 3. Laboratory Tests of Cameras and Windows [Penn State EOC Led - SOW 5.4] Execute IPT approved test plans for laboratory experiments using temperature sources and fabricated fixturing to simulate both good and faulty electrical connections Evaluate various configurations IR imaging, window, panel, configurations 4. Devise Practical Implementation [Penn State EOC, HII & SSGC - SOW 5.5] Review representative panel types and parameters existing in current inspections including: sensitivity to camera position/angle, temporary/permanent requirements, practical and operational considerations Determine implementation plan, including number and placement of IR window(s), camera positions and potential obstacles for representative electrical panels (Continued on Next Slide) 17

18 Technical Tasks (Continued) 5. Plan and Prepare for Final Demonstration [Penn State EOC, HII & SSGC - SOW 5.6] Determine the final demonstration scenario, expected to occur at SSGC A representative electrical panel will be modified and used to first mimic an actual inspection in the lab Execute procedures for demonstration, including number of tests, camera position and angles, visible inspection and verification of results. 6. Develop Technology Transition Path Including Safety/Business Case [All - SOW 5.7] Compare of the demonstrated solution against the existing process (including manhours, cost to file a waiver / use PPE, etc.) Identify and vet the path for transition and implementation (temporary / permanent) Vendors and suppliers will be identified to support production as appropriate 18

19 NFPA 70E, Standard for Electrical Safety in the Workplace, 2015 Edition Main question: Does NFPA 70E support the premise that performing Infrared Thermography on an energized panel through a window in a closed door or cover eliminate the need for PPE and OSHA waivers? Table 130.7(C)(15)(A)(a) pg. 36 states that performing infrared thermography outside the restricted approach boundary does not require PPE, but that this activity does not include opening doors or covers. This implies that IR thermography through a window in a closed door does not require PPE. Need to determine if this is in fact, the case. In Table 130.7(C)(15)(A)(a) for all other tasks, generally speaking, if doors and covers are in place, no PPE is required. Does this apply to windows in doors? 2015 edition of standard places an emphasis on risk assessment. Imaging through a window in a door involves significantly less risk than through an open door. Is this sufficient to remove the hazard of arc flash? Standard states in multiple places (pg. 4, pg. 37) that where an arc flash is not likely to occur or there is no arc flash hazard, PPE is not required. Does this imply that if a window protects from arc flash, no PPE is required? 19

20 Assumptions & Requirements (From Kickoff) Information desired before proceeding 1. Is there a published procedure for IR inspection? 2. Besides FLIR E-50 (Ingalls) & FLIR EX320 (SUPSHIP): What other cameras are used for IR inspection? 3. What is the standoff distance from camera to circuit? 4. What observed temperature difference constitutes a pass or fail condition? 5. Is IR thermography sensitive to off angle viewing? If so by how much? 6. What cameras are available for borrowing and for what time frame? 7. Is a visible camera image for comparison a requirement? 8. What options are available for getting an actual panel cover? 9. Can we get dimensions/drawings/information for typical panels/inspection scenarios so as to set realistic laboratory conditions? 10. What are obstacles/safety concerns in performing a demonstration as envisioned (energized panel, IR through window in door)? Any logistical concerns? 11. Consensus that scope of demo will include only 4,160V panels. Will not attempt to cover 13,800V panels in this phase. 12. Any others? 20

21 Safer Inspection of Medium Voltage Electrical Panels on Navy Ships Concerns and Risks Technical» Will IR transmissivity through window significantly affect measurements?» If required, can visual inspection be performed through same window?» Will the geometry of some panels make imaging through windows impractical?» Will windows be considered enough arc flash protection to preclude needing PPE? Programmatic» Logistical/cost issues with borrowing/purchasing cameras and shipping panel components» Safety, logistical, or timing issues that may make the demonstration impractical» Scope creep 21

22 Meetings and Reviews [Penn State EOC Led - SOW 5.1] Kickoff Meeting A kick-off meeting will be held with key players to (1) review project plans, (2) confirm availability of equipment and testing site and (3) make any revisions to project plans based on IPT input and guidance. This meeting occurred at HII Pascagoula Bi-Monthly Teleconferences Four (4) teleconferences will be conducted to facilitate team communication and updates pertaining to progress and status. These teleconferences are scheduled in correlation with project milestones and meetings to assure the integrated project team is engaged in formal communications at least every 2 months throughout project execution Technical Interchange Meeting to Review Initial Research At this meeting, the results of initial research into IR inspection windows suitable for the camera(s) to be used will be discussed, a candidate system for testing and demonstration will be identified, and preliminary test plans will be conveyed. The outcome of this meeting will be agreement to proceed with procuring equipment and materials. This meeting is likely to occur at Penn State EOC. Timeline To occur upon completion of initial research phase, specifically upon conclusion of task 5.3, Determine Camera(s) and Window(s) to be Used Final Review Meeting and Demonstration Hold a Final Project meeting to review project success. Present proof of concept demonstration in relevant setting. Final project results and implications will be presented. This meeting likely to occur at SSGC Pascagoula, but venue to be determined during the course of the project. Timeline Before conclusion of the project which occurs 12 months after project funding is received by all parties. 22

23 Master Integrated Schedule (v.2/13/15) 23

24 Other Solution Concepts IR Fibers for Blackbody Radiation [NNS via Deleo] IR Fibers for Blackbody Radiation 1. One potential avenue is to use IR fibers to transmit blackbody radiation to a high density FO connector on the face of the panel. 2. Connector can then be read by a variety of methods. Can even develop a special tool to automate scanning. 3. This allows a high level of flexibility with regard to mapping the inside of a panel and monitoring areas without a direct line of sight. 4. You can also easily accommodate a large number of measurements without a significant impact to the panel face (just a connector and dust cap). Pro s: 1. Non-conductive materials eliminate short circuit potential 2. No EMI concerns 3. Not a tactical concern (failure or loss doesn t degrade performance of equipment) 4. Flexible and can be added easily to a design with minimal risk to military qualifications 5. Field installable 6. Lends itself to automation in the future 7. Simple installation. Fibers are not required to carry data so precision installation not an issue. Large light loss acceptable. You only need enough to measure radiation frequency to determine temperature. 8. High quality FO conductors exist 9. High quality (and Mil Spec) connectors exist (Mil-DTl-38999) at high densities (e.g. 64 conductors in small footprint) Con s: 1. Not consistent with current inspection practices 2. Expensive / impractical retrofit? 24

25 Other Solution Concepts Embedded Temperature Sensor & Camera [via Mako & Smith] FLIR AX8TM Combining thermal and visual cameras in a small, affordable package, the AX8 provides continuous temperature monitoring and alarming for uninterrupted condition monitoring of critical electrical and mechanical equipment. 1. The AX8 provides early detection of temperature-related issues in electrical and mechanical equipment, making it the ideal temperature sensor for continuous condition monitoring and hot spot detection for electrical cabinets, process and manufacturing settings, data centers, mass transit facilities, energy generation plants, and storage facilities. 2. Easy to install in electrical cabinets or other confined areas, the AX8 provides uninterrupted condition monitoring of critical electrical and mechanical equipment to help reduce unplanned downtime and prevent safety hazards. 3. Learn more about this powerful thermal sensor and camera, and its many practical applications: Pro s: 1. Continuous condition monitoring 24/7 2. Excellent solution for new construction (pending cost/safety benefit) Con s 1. Not consistent with current inspection practices 2. Expensive / impractical retrofit? Pending Further Investigation 25

26 Results of Initial Trade Study EOC s initial analysis identified preliminary requirements and potential solutions for both temporary installations acceptable before and during sea trials as well as permanent solutions which must be compliant with Mil-Specs for shipboard operations Leading candidate solution: temporary or permanent installation of panel covers with IR transparent windows enabling safe IR inspection without exposing personnel to active electrical components This would allow inspectors in the room to operate at any time before/during acceptance/sea trials without PPE, while utilizing the same cameras and practices currently used but without the cumbersome and costly need to secure the area and deactivate and reactivate electrical switchboards. Besides IR windows, potential solutions with pros and cons of each were identified including: Curtain RF interrogation of embedded temperature sensors A standalone gantry for remote imaging temperature sensitive paint Candidate solutions were vetted through NSRP Electrical Technologies Panel (ETP) presentations and subsequent stakeholder interactions With the support of this community, the approach was refined such that this project focuses on demonstration of temporary (or permanent) installation of panel covers with IR transparent windows enabling safe IR inspection without exposing personnel to energized electrical components 26

27 Initial Trade Study Solution Concepts Panel with IR Transparent Windows (Temporary or Permanent) Replace panel with a temporary panel that has IR transparent windows in it. 1. Windows would be small to keep costs down. 2. Multiple windows would supply the required angles and fields of view. 3. Small panels, some of each with windows, can be modular. 4. An entire panel might consist of 9 subpanels, of which 3 or 4 would have windows. 5. The subpanels would be reconfigured to match the best viewing angles for the switchboard that is being inspected. 6. Some of the windows could be in angled conical mounts so as to direct the FOV somewhat off of normal. 7. Rotating conical mounts like this would allow this angle to be aimed in any direction. 8. The power would be shut off while the regular panel is removed and this temporary panel takes its place. Power restored then inspection takes place same as the old inspection. 9. Temporary panel removed and taken to next switch panel. 10. Temporary panel can be reconfigured if necessary. Pro s: 1. Allows inspectors in room, permitting inspection at any time, including underway 2. Inspection can be done with same cameras and techniques used now. Con s: 1. Requires temporary shutdown of panel while temporary panel installed or removed. 2. Geometry dependent. Even with modular subpanels, might be difficult to get the best location and best angles for meaningful test. 3. Unclear whether one size will fit all. May need more than one set, or some adaptor to make it fit on different size panels. Other Issues / Determinations: 1. Wide array of LWIR transparent windows materials: ideal would be one that has high visible (~ 80%) and IR (>60%) transmission, large/standard size, and durability to withstand a flash event (not be blown out or melt). Cost implications 2. Could use separate IR/Vis windows unless it is possible to take the vis pictures after the inspection is over and the panel is shutdown for removal of our temporary panel 27

28 Initial Trade Study Solution Concepts Curtains - Subset of Panel with IR Transparent Windows Curtains (subset of Panel with IR Transparent Windows): Instead of panel with conical camera ports, create a curtain with a port in the middle. 1. Curtain would resist spark and flame, like welding curtains. 2. Can make it from same material as the flash protection suits. 3. Curtain could be sewn so as to form pyramidal or conical general shape. 4. Curtain flexible enough to allow camera to be moved around to exact position and angle desired. If looking through camera lens, no window in curtain will be needed, just a hole to poke the camera through. 5. Camera may need lights for the visible pictures. Pro s: 1. Simpler than panel 2. More flexible in positioning camera 3. No IR window needed 4. Not very expensive Con s: 1. Not sure welding curtain type cloth will be acceptable. (flash protection suit material should be acceptable) 2. May be unwieldy to move camera surrounded by thick curtain 28

29 Initial Trade Study Solution Concepts Temp Sensor w/rfid Interrogation Temp Sensor w/rfid Interrogation 1. Researched commercially available: see below, - Temp Sensor w/rfid Interrogation 2. Use a contact temperature sensor with RFID-like (wireless) interrogation. Pro s: 1. No change to existing panels 2. No camera required to inspect documentation with auto logging of sensor serial #/location 3. Gather data when convenient. Panels operated normally no open panels, no personnel safety issues. 4. Geometry independent camera same angles as with present inspection Con s 1. Requires additional steps to add and remove sensors and create database of sensor locations 2. Unknowns/Issues: 3. EMI interference with panel closed when trying to read? Unlikely but Need more research 4. Cost? 5. Perhaps make a permanent installation? 6. Variation: has a product called Delta T Alert, which is a wireless device you put on the door and it monitors temperature inside the cabinet vs. outside, and logs data at regular intervals. Can set up a network of these. Only measures entire cabinet temperature, but one testimonial credited it with alerting him to a phase unbalance in one of his cabinets. Perhaps part of the long term solution. 29

30 Initial Trade Study Solution Concepts Remote Operated Camera Gantry System Standalone Gantry with PTU 1. Build a man-high frame with a motorized X-Y gantry on it. On the gantry, mount the camera on a PTU. 2. Shut down the switchgear, remove the panels, set up the frame where a person would stand to do the inspection. 3. Gantry and PTU permit the camera to be placed anywhere a person would place it. Control everything remotely. 4. When inspection finished, shut down power remotely, replace panels and move on. Pro s: 1. Can get all of the viewing angles that are currently available. 2. Probably simplest to implement (X-Y and PTU do not need to be of any great precision) 3. Costs are low, depending on the camera Con: 1. Need a camera that can be operated remotely 2. Probably will be wired, so will need to see what safety issues there are running cables out of the room. 3. Bulkiest of the potential solutions. 4. Requires people to be out of room, so would be difficult to implement while underway. Subset (Gantry with PTU inside panel box) 1. Reproduce the XY gantry with PTU in a box that hangs on the switchgear in place of the regular front panel. Shut down panel, remove front, replace with this box, re-energize and do inspection. Pro: 1. Panel is closed so inspection can be done with people in room and done at any time. 2. Fairly low cost XY gantry and PTU do not need to be of great precision Con s: 1. Of necessity will have camera fairly close to panel. FOV and focus might be problematic that close Camera might be bulky 2. Difficult if panels are significantly different in size 3. Projection from panel might be an issue. 4. Need remotely operated camera 30

31 Initial Trade Study Solution Concepts Temperature Sensitive Paint Temperature Sensitive Paint There are paints that change color depending on their temperature (thermochromic). There are both irreversible (which stay at the color they changed to at their highest temperature) and reversible (which change back to their original color when the temperature returns). In the case of irreversible, it is often a change in density of the same color, so the color darkens. They could be incorporated in the following manner: Subset (Irreversible Thermochromic Paint) The paint can be applied on assembly or prior to inspection to the potential hotspots (terminals on cables, studs on panels). If desirable not to introduce paint to the components, pads can be constructed with the thermochromic paint on the top and an adhesive backing. Prior to inspection, these pads can be applied to the potential hotspots. After the panel is powered up, then shut down, the cabinet doors are opened and the colors on the pads examined. Those that were hotter will have darker or different color than their neighbors in the same circuit. Comparison color charts can be made up that can be held against the pad in the panel to judge a maximum temperature reached. Photos can be taken with visible light color camera. Pro s: 1. No change to existing panels 2. No camera required to inspect documentation with a visible camera only 3. Panels operated normally no open panels, no personnel safety issues. 4. Geometry independent camera same angles as with present inspection Con: 1. Will change color only when absolute temperature exceeds threshold. A bad connection may not indicate at less than full current (lower temp). 2. Requires additional steps to add and remove pads 3. Temperature sensitivity may not have fine enough resolution to tell difference between a few C. (ACTION) Need more research. 4. Need to have the pads made up. 5. If paint applied directly, then would need to pass approval to be permanently installed inside the cabinet. Also, would need to be stripped off and reapplied for each retest. 6. Requires shutdown of panel both before (to install the pads) and after (to read the results) Subset (Reversible Thermochromic Paint) The paint can be applied on assembly or prior to inspection to the potential hotspots, either directly, or via the pads described above. Panel replaced with temporary panel containing visible transmission windows. Inspection done while panel energized and color change is noted by comparing color of different phases of the same circuit. Done with visible camera for inspection or just documentation. Pro s: 1. No camera required to inspect documentation with a visible camera only 2. Much more flexibility in obtaining appropriate visible windows than IR windows. 3. Transmission much higher through visible windows (closer to 100 %). 4. Less geometry dependent visible windows can be larger to cover more angles than IR Con s: 1. Will change color only when absolute temperature exceeds threshold. A bad connection may not indicate at less than full current (lower temp). 2. Requires additional steps to add and remove pads 3. Temperature sensitivity may not have fine enough resolution to tell difference between a few C. Need more research. 4. Requires temporary shutdown of panel while temporary panel installed or removed. May not be able to open panel quickly enough to catch change 31

32 Initial Trade Study Solution Concepts Other Ideas Considered but Not Explored in Initial Trade Study Flexible Camera Head Through Louvers (borescope) 1. IR camera with imaging head on gooseneck, probably (non-conductive) fiber optic. 2. Insert camera head through louvers in existing panel while switchpanel is energized. 3. Move camera head around via gooseneck, or attached to insulating rod or other manipulating device. 4. Move to different louvers to get best view. Pro s: 1. No change in existing panels 2. No requirement to shut panels off while equipment is installed or removed. 3. Test can be done at any time, including while ship is underway Con s: 1. Highly geometry dependent. Doubtful that all relevant views can be obtained through louvers. Unclear if required manipulation can be done through louvers. 2. Requires penetration of plane of panel Potential safety issue, even if camera head is isolated Embedded Camera Ports (Subset to Temporary Panel/Curtain) 1. Instead of IR windows, have subpanels with camera ports, probably conical to the outside of the panel. 2. Camera goes at peak of cone, but has ability to be angled in pan and tilt. Inside of cone has mechanical shutter. 3. Panel is installed in place of regular panel. All shutters are closed. 4. Camera is installed in one port, and then shutter is opened. 5. Camera angled for best view and test performed. Shutter closed and camera moved to next port. Pro s: 1. Less expensive than multiple IR windows Con s: 1. May not get all the angles needed with camera fixed at end of cone 2. Possible mechanical challenge to allow PT at port while still protecting from HV discharge within 32