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FY15 NSRP ETP Panel Project
Safer Inspection of Medium Voltage Electrical Panels on Navy Ships
NSRP ETP Panel Meeting Electrical Panel Meeting, San Diego, CADecember 9, 2015
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Penn State Electro-Optics CenterThe Navy Manufacturing Technology Center of Excellence for Electro-Optics222 Northpointe Blvd.Freeport, PA 16229
Jeff CallenResearch and Development Engineer Electrical Engineering and Systems Engineering724-295-7000, ext. [email protected]
Matthew E. DiGioiaEngineering Project ManagerAssistant to ManTech Program Operations724-295-7000, ext. [email protected]
DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.
Presentation Outline
1. Project Background
• Issue & Approach
• Participants & Stakeholders
• Technical Approach & Deliverables
2. Status Update
• Lab Testing Results
• Milestones
3. Summary Quad / End
4. Backups
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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, SUPSHIP Gulf Coast]
• Newer ships have electrical systems considered medium to high voltage
– LHD, LHA, DDG-51(FLTIII), DDG-1000 = Medium, 4160 volt systems (CVN = High, 13,800 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
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Safer Inspection of Medium Voltage Electrical
Panels on Navy Ships
Load Center
Temperature difference between phases
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. Some
facilities will not open panels for inspection on 4160V, even with PPE.
• 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
– Allows 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.
• Candidate solutions were vetted through NSRP Electrical Technologies Panel (ETP) presentations and
subsequent stakeholder interactions.
• Besides IR windows, potential solutions with pros and cons of each were explored including a
standalone gantry for remote imaging, temperature sensitive paint, and RF interrogation of embedded
temperature sensors
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Safer Inspection of Medium Voltage Electrical
Panels on Navy Ships
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
• New MIL-DTL-32483, dated 8 Nov. 2013, DETAIL SPECIFICATION SWITCHGEAR, POWER, HARD-
MOUNTED, MEDIUM VOLTAGE, NAVAL SHIPBOARD, requires use of thermal imaging windows.
LHA 8 invokes MIL-DTL-32483 for 4160V Switchboards.
Lead Investigators
Jeff Callen Penn State Electro-Optics CenterResearch and Development Engineer,Electrical Engineering and Systems Engineering
Matthew E. DiGioia Penn State Electro-Optics CenterEngineering Project Manager, ManTechSensors, Robotics, and Automation
Sponsoring Shipyard
Jason Farmer Ingalls Shipbuilding (Pascagoula)Project Lead / Electrical Engineer IV
Government Stakeholder
Clay Smith SUPSHIP Gulf CoastEngineering
Project Technical Representative
Richard Deleo Newport News ShipbuildingEngineering Manager - Submarine Electrical
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Active Project Participants
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Integrated Project Team (IPT):
Advisors and Other Stakeholders
Government Stakeholders
Dave Mako NSWC Philadelphia Division, Code 427, Propulsion & Power Systems
John Zabita NSWC Philadelphia Division, Code 511, Instrumentation & Sensors (IR Thermography)
Industry Advisors
Gary Weiss DRS Power & Control Technologies, Inc.Business Development Manager for Power Distribution and Power Conversion
John Ykema L3 SPD Electrical Systems, VP and CTO [email protected]
Other Interested Parties
Tom Connolly NSWC Philadelphia Division, Code 427, Propulsion & Power Systems
Greg Stevens Bath Iron WorksElectrical Engineering
Dennis Neitzel AVO Training Institute, Inc.OSHA Authorized Maritime TrainerPrincipal Committee Member, NFPA 70E
Process and Means to Accomplishing Goals and Objectives (from SOW)
Review Shipbuilder/Government/Industry Requirements for IR PanelInspection and Current Inspection Practices [HII, SSGC & Penn StateEOC]
Determine Camera(s) and Window(s) to be Used [Penn State EOC Led]
Laboratory Tests of Cameras and Windows [Penn State EOC Led]
– Devise Practical Implementation [Penn State EOC, HII & SSGC]
– Plan and Prepare for Final Demonstration [Penn State EOC, HII & SSGC]
– Develop Technology Transition Path Including Safety/Business Case[All]
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Technical Approach
Deliverable6.1 Proof of Concept Demonstration
A demonstration of IR thermography through one or more IR windows installed in the door of a 4160Vswitchgear panel that is representative of the type of switchgear panels to be on LHA-8 and similarvessels. Demonstration for sponsors and IPT ~ late January 2016.
Originally Targeted LHA-7 Sea Trial (trials scheduled for late Summer 2016 = outside PoP) Now Exploring Testing @ DRS’ Milwaukee Facility:
– Thermography Demonstration in DRS’ prototype 4160V switchgear panel and testing facility• Make main power connections to the panel busbar (two phases minimum, three preferred)• Energize panel connections with low voltage, high current to simulate properly operating panel
(temperatures of phases approximately equal and typical of full load temperatures)• IR thermography imaging through IR windows mounted in panel cover. Window and camera placement such
that viewing can be done around internal obstructions in the cabinet.
– Thermography Demonstration with Simulated Fault• Simulate a potential bad connection by altering the test conditions so that one phase connection is
significantly higher temperature than another phase.• Repeat IR thermography through Windows
– Assistance in fabricating a panel door cover modified with IR windows(s)• DRS and EOC jointly determine location of two IR windows such that imaging of main bus connections can be
done through the windows, taking internal obstructions (structure, phenolics, other cables) into account.• EOC supplies DRS with two IR windows• DRS supplies a surrogate cover for the panel and installs the window(s) in the predetermined cover locations
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Reporting Deliverables
6.2 Quarterly Reports: April, July, and OctoberReport Outline:
(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
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Project Update
IR Windows – Crystal vs. Polymer• Crystal Windows
– Pro: Vis and IR, no reinforcement grid.
– Con: possibly could deteriorate over time (reviewing this issue), transmission cuts off midway
through long IR band
• Polymer Windows
– Pro: no deterioration, full IR band, some rectangular
– Con: Need reinforcing grid, some will not pass vis light (need separate window)
Cameras and IR Windows
• Cameras
– FLIR EX320 from SUPSHIP-GC
– Fluke TI32 from Ingalls
– FLIR T440 borrowed from FLIR
• Windows
– FLIR IRW-4S: 4” round crystal (matches LHA-8 spec)
– Fluke CLirVu CV400: 4” round as a 2nd crystal window
– Exiscan XIR-A-4-H-X: 4” square polymer window
– IRISS VPT-100: 4” round as a second polymer window
Laboratory Testing
• Tested both polymer and crystal windows, plus multiple cameras
• Established basic performance: accuracy with and without windows, temperature range,
Field of View, visible transmission, view actual cable with lugs and simulated temperatures10
Laboratory Test Results - 1
Cameras
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4” Windows (covers removed)
FLIR T440 Fluke TI32
FLIR EX320 from SUPSHIPSnot used
FLIR IRW-4S Fluke CV400 IRISS VPT-100 Exiscan XIR-A-4-H-X
Laboratory Test Results - 2
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Blackbody HeadWindow Fixture
Camera mounted
FLIR IRW-4S window with T440 Camera
Blackbody Controller
Test Setup
• Camera, windows and targets fastened to fixtures on optical table for repeatability
• For most tests, target was CI Systems model SR-80 blackbody radiation source (20°C to 87°C).
7” by 7” radiation face (emissivity = 0.97)
• Windows clamped to fixture for quick interchangeability. Window 18” from target, camera 1”
from window.
Laboratory Test Results - 3
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Camera Tests
• FLIR T440 and Fluke TI32 tested without windows at three temperatures. FLIR EX320 not tested.
• RESULTS:
– Differences between cameras were minor and both were judged to have performed
essentially the same without windows.
Window Comparison
• All four windows tested with both cameras at two temperatures.
• Reading without window taken, then with window installed, transmissivity of camera adjusted so
that temperature was same as that without window.
• RESULTS:
– Accurate measurements were made with both window types.
– Transmissivity settings indicate more attenuation in the crystal windows.
– The two crystal windows are virtually identical to each other.
– The reinforcing grids on the polymer windows were evident in
the images and affected temperature readings slightly.
– Small variation (a few percent) in transmissivity settings
between cameras and between tests.
Laboratory Test Results - 4
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Horizontal and Vertical Field of View (T440 Camera/FLIR and IRISS Windows)
• Blackbody source masked for a more realistic target.
• Camera fixed in place and target moved left and right until reading no longer possible.
• Distances measured and angle calculated for maximum horizontal field of view.
• Camera and mask rotated 90°. Test repeated for vertical field of view.
• Camera has a standard lens which has an HFOV of 25° and a VFOV of 19°.
Thermal Image of target mask size and shape of connection lug
Camera and target mask rotated for vertical field of view test
Laboratory Test Results - 5
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Horizontal and Vertical Field of View Results
• Horizontal and vertical field of view through both windows was very large –span
width and most of height of representative cabinets.
• Camera positioned and angled for best view
• Temperatures dropped at far extreme angles for both windows (more material at
shallow angle)
• Drop off more severe for polymer window (more of reinforcing grid)
Window HFOV VFOV Temp drop at extreme edge
Crystal (FLIR) 129° 127° 10%
Polymer (IRISS) 114° 115° 28%
Digital image through polymer window at shallow angle
Laboratory Test Results - 6
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Simulated Fault, with cable and lugs
• Two samples of representative T400 cable with connecting lugs bolted to copper bus
bar with 500 W power resistor mounted to the rear.
• Temperatures of the two lugs set to different values by running a different current
through each resistor as a heater. Stabilizes in about 1 hour.
• Images taken with no windows and with the crystal window and the polymer window
Cables and Lugs on bus bars
• Black tape for setting camera emissivity (bus bar and lugs stabilize at same temperature). Measure temperature on tape with emissivity set high (0.95). Set emissivity for lugs to obtain same temperature.
Rear view, power resistors as heaters
Laboratory Test Results - 7
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Simulated Fault, with cable and lugs - Results
• Temperatures varied considerably – highly sensitive to placement of measurement
spot (surface variations). More repeatable with measurement box.
• Navy compensates for variations by mandating an
emissivity setting of 0.8, rather than have each
operator estimate the setting. Tests done at different
times and by different operators can be compared.
• Comparison between electrical phases more
important than absolute temperatures.
• With emissivity at 0.8, readings through crystal
window are a little high for the upper temperature, and
readings through polymer window are a little low.
• Transmissivity settings taken from previous tests and
result in slight differences in readings.
TAKEAWAY: As the Navy does for emissivity settings, a practical test will need to
establish proper transmissivity settings to result in a test that errs on the side of
safety while allowing comparative tests.
Laboratory Test Results - 8
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Rubber Dust Boot
• Not strictly an IR Window issue, use of rubber dust boots over the bus bar
connections will affect the thermography.
• Rubber (exact material unknown) boots are placed over bus bar connections to
reduce the clearance distances required to avoid arcing, tracking and electrical creep.
• Sample boot tested with cable and lugs test setup. Installation jury rigged (not same
geometry) to cover lugs and be enclosed. Some air gaps remained.
• Two lugs were heated until about 34°C apart then
allowed to stabilize over 3-4 hours to allow heat
to build up underneath the boot.
• No windows. Measurements at multiple points
• Camera distance 27” for more in field of view.
• Emissivity 0.95 based on tests with the boot
material.
Laboratory Test Results - 9
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Rubber Dust Boot Results
• Hot spots in various locations – small air gap or touching.
• Max temperatures about 20°C lower than
temperature of the lug beneath it.
• Despite ill fitting boot on test setup, still a
noticeable difference between hotter and
cooler sides.
• Also measured cable temperatures below the
boot - temperature difference 35°C between
lugs and about 20°C between cables.
• Repeated test with crystal window with
identical results.
• Definitive quantitative data not possible from this test, as fit of boot allowed large
air gaps in places.
• Sufficient differences between hot spots on boots or cables to indicate one
connection is significantly hotter than adjacent connection.
Laboratory Test Results - 10
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Visible Imaging
• Visible images put thermal image in context to identify location. Thermal imagers have visible camera and lamp built in.
• Visible images taken through both crystal and polymer windows. Two issues were evident.
• Reflection off the window face when illuminated by camera
lamp.
• Imaging through windows will have cabinet cover closed,
and no internal illumination. Glare is worse on the polymer
window reinforcing grid.
• Crystal window provided no obstruction to the image.
• Polymer window, though clear, has reinforcement grid.
Grid does not affect thermal image significantly, but is
present in the visible image.
• Images can be taken through polymer reinforcement grid, but requires careful
camera positioning
• May be necessary to use another illumination source - same window or another
location to illuminate the target area.
Laboratory Test Results - Conclusions
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These tests established baseline on how windows affect measurements and provided insight on
impacts to shipboard thermography inspections. Environmental tests on windows outside project
scope.
Conclusions:
1. Reasonably accurate temperature measurements can be made through IR windows provided
attention is paid to emissivity and transmissivity settings in the camera.
2. Variations in emissivity and transmissivity will need to be minimized by developing uniform
techniques and procedures to provide a useful comparison test, as is done presently with
emissivity settings.
3. Windows allow wide enough field of view that number and placement of windows in the
cabinet will be limited only by the internal obstructions and line of sight views.
4. Polymer window reinforcement grids affect thermal measurements slightly, but also affect
the field of view and make visible imaging difficult.
5. Rubber dust boots do affect the absolute thermal measurements. Hot spots will show up on
the boot or cable, but it was not possible to quantify the differences properly. More study is
needed.
6. Reflected glare indicates that for visible imaging in a closed cabinet, some other illumination
source will be needed, either through the same window or through some opening.
Summary Milestones (NCE Pending)
1/19/15: Contract awarded to EOC
2/11/15: Kickoff Meeting occurred @ HII
4/10/15: Quarterly Report #1
4/16/15 (Thur): 1st Telecon (review requirements & camera selections, Quarterly Report #1)
6/10/15: 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
Jul 2015: Quarterly Report #2
Aug 2015: 2nd Telecon (review finalized lab experiments & plans)
Oct 2015: Quarterly Report #3
Oct 2015: Technology Interchange Meeting @ EOC (was “3rd Telecon”) Review lab results and discuss practical implementation plans
– Jan 2016: 4th Telecon (finalize plans for demo)
– Jan/Feb 2016: Demonstration (@DRS)
– Mar 2016: Draft of Final Report (w/ Transition Path Developed) Delivered (in advance of Final Review)
– Mar 2016: Final Review Meeting (Telecon) [Deliverable]
– Apr 2016: Update & Deliver Final Report [Deliverable]
– 4/20/16: End of EOC Period of Performance (NCE Pending)
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Safer Inspection of Medium Voltage Electrical Panels on Navy Ships
Safer Inspection of Medium Voltage Electrical Panels on Navy Ships
Implementation: System: Medium & High Voltage Electrical Infrastructures
on Navy Platforms (LHD, LHA, CVN…)
Site: LHA-7 SUPSHIP-GC (Proof of Concept Demo - Future)
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
Sponsor: The National Shipbuilding Research Program2014 Electrical Technologies Panel Project
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 – Philadelphia Division, OSHA Safety Trainer, Industry Product Supplier
Tasks/Achievements: 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 Review Shipbuilder/Government/Industry Requirements for IR
Panel Inspection and Current Inspection Practices 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: Quarterly Reports: April, July, and October• Proof of Concept Demonstration: representative IR thermographic
inspection using an IR window in closed electrical panel cover• Final Project Report: Jan-16
Average of 8 arc faults per year throughout the navy fleet - all occurred in Switchboards and Load Centers – can result in serious injury and costs Navy millions of dollars in downtime and repairsCurrent 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.
NOV15DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.
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BACKUPS
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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 panelcovers to reduce risk for government and shipbuilder inspection of onboard medium/highvoltage 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 waiverrequests 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 costlyneed 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 andshipbuilder applications
• Develop the business case and risk reduction benefits for shipbuilder construction and governmentapplications 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 thatmeet temporary installation requirements
• Explore the criteria and viability for permanent installations within MIL-DTL-32483 (RevA pending)
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Safer Inspection of Medium Voltage Electrical
Panels on Navy Ships
Project Assumptions
1. 4160V 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.
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Project Requirements
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, possible FLIR T400)
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.
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Camera Compare
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Window CompareNo. LHA-8 Spec FLIR IRW Series FLIR IRW S* Exiscan XIR-A-
4-H-XExiscan XIR-A-3-H-X
Exiscan XIR-S-4-H-X
Fluke CLirVu Fluke CLKT IRISS VPFC IRISS VPT
1 Permanently attached cover Y Y Y Y Y Y N Y Y
2 Single hole installation Y Y No, 8 bolts No, 8 bolts No, 8 bolts Y 3 self tap screws ?? ??
3 standard hole punch install Y Y Saw or punch Saw or punch Saw or punch Y Y ?? ??
4 Solid metal cover Y Y Y Y Y Probably Probably Y Y
5 No tools to open window single thumbscrew
single thumbscrew
4 hex head captive screws
4 hex head captive screws
4 hex head captive screws
1/4 turn hand turn captive
Hex head screw Phillips screw Phillips screw
6 Broadband (vis and thermal) Y Y No, separate window for vis
No, separate window for vis
No, separate window for vis
Y Y Y Y
7 No obstructions, including reinforcing screens
Y Y Diamond reinforcing screen
Diamond reinforcing screen
Diamond reinforcing screen
Y Y Y Hex reinforcing screen
8 Rated to 250 °C 260 °C 260 °C 150 °C 150 °C 150 °C 232 °C & 260 °C intermittent
250 °C 200 °C 200 °C
9 Stainless Steel housing Anodized Alum. 316 Stainless Stl anodized Alum, pwdr coat
anodized Alum, pwdr coat
Stainless "high strength alloys"
Aluminum Nylon Nylon, SS cover
10 Pull out strength 3600 lbs. 2" 1450 lb. 3" 3650 lb.4" 3700 lb.
2" 1450 lb. 3" 3650 lb.4" 3700 lb.
No Spec No Spec No Spec No spec 1388 lb. No Spec No Spec
11 Rated low, med, high voltage Y Y Y Y Y Y Y ?? ??
12 Meet UL 50V Y Y Y Y Y Y ? Y Y
13 Meet UL50 Environ. Type 4/12 4/12 4/12 4 4 4 4/12 3/12 4 4
14 Meet KEMA (IEC 62271-200) Arc flash 5kV, 63 kA 30 cycles 60 Hz.
5 kV, 63 kA 30 cycles 60 Hz
5 kV, 63 kA 30 cycles 60 Hz
ANSI/IEEE C37 20.7
ANSI/IEEE C37 20.7
ANSI/IEEE C37 20.7
63 kA 30 cycles 60 Hz, meets C37 20.7
C37.20.7 50 kA for 30 cycles 60 Hz
?? C37.20.7 63 kA, 15 kV for 30 cycles 60 Hz
15 Meet TUV (IEC 60529) IP67 IP 67 IP 67 IP65 IP65 IP65 IP67 IP65 IP65 IP65
16 Meet TUV (IEC 60068) 100 m/s2
vibration100 m/s
2100 m/s
2No Spec vibration "unaffected"
No Spec vibration "unaffected"
No Spec vibration "unaffected"
IEC 60068-2-6 IEC 60068-2-6 ?? ??
17 Meet TUV (IEC ^0068-2-3) 15 day extreme humidity
Y Y Humidity & moisture "unaffected"
Humidity & moisture "unaffected"
Humidity & moisture "unaffected"
IEC 60068-2-3 IEC 60068-2-3 ?? ??
18 Optic Material Calcium Fluoride Calcium Fluoride Polymer Polymer Polymer Crystal Crystal Calcium Fluoride Polymer
Master Integrated Schedule (v.6/2/15)30
Other Solution ConceptsIR Fibers for Blackbody Radiation [NNS via Deleo]
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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?
Other Solution ConceptsEmbedded Temperature Sensor & Camera [via Mako & Smith]
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FLIR AX8TMCombining 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: http://www1.flir.com/e/5392/automation-display--id-65816/xm2jz/892531353
Pro’s:1. Continuous condition monitoring – 24/7
2. Excellent solution for new construction (pending cost/safety benefit)
Con’s1. Not consistent with current inspection practices
2. Expensive / impractical retrofit?
Pending Further Investigation
Results of Initial Trade Study
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
• 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
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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
Initial Trade Study – Solution ConceptsPanel with IR Transparent Windows (Temporary or Permanent)
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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
Initial Trade Study – Solution ConceptsCurtains - Subset of Panel with IR Transparent Windows
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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’s1. 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: www.iriss.com 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.
Initial Trade Study – Solution ConceptsTemp Sensor w/RFID Interrogation
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Standalone Gantry with PTU1. 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
Initial Trade Study – Solution ConceptsRemote Operated Camera Gantry System
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Temperature Sensitive PaintThere 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
Initial Trade Study – Solution ConceptsTemperature Sensitive Paint
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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
Initial Trade Study – Solution ConceptsOther Ideas Considered but Not Explored in Initial Trade Study
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Laboratory Test Results - 4
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Downselect
• Though the two cameras were both adequate for the measurements, further testing was down only
with the FLIR T440. This camera was selected for its feature set and it is representative of the
cameras used by the Navy.
• The FLIR and Fluke crystal windows were virtually identical in performance but the FLIR was
chosen as being closest to the preliminary specifications for LHA-8.
• The Exiscan polymer window was set aside as it is translucent to visible light and would preclude
taking visible images. Also it was hard to focus the IR image through it. The IRISS polymer was
used in subsequent tests.
Range Test
• The FLIR and IRISS windows were tested with the blackbody set to 25°C, 35°C, 45°C, 55°C, 65°C,
75°C and 85°C.
• RESULTS:
– Accurate readings could be made with both windows of the full temperature range provided transmissivity
was set appropriately.
– Some slight variation of transmissivity setting was seen (a couple of percent) to get the readings to match
the no window temperature across the range.
– The largest deviation was at 25°C, but the blackbody source is not as reliable when set near the ambient
temperature.
Laboratory Test Results - 6
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Simulated Fault
• Two blackbody radiation sources were placed side by side and their faces masked with black tape
to leave an area on each the size and shape of a connection lug.
• The back bodies were set to different temperatures and measurements were taken with both
windows at temperature differences between the two sources of 5°C, 20°C, 40°C, 50°C and 60°C.
• Camera transmissivity settings were taken from previous tests with these same two windows.
Thermal image of two targets 20°C apart, through crystal window
Results
• Differences between the two windows was small. Measured temperatures were within 2-3°C of
each other for the same measurement when using either window.
• There is some sensitivity to the transmissivity setting, as was seen in earlier tests, affecting
readings by a few degrees.