How to inspect an electric panel with an infrared camera
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- Опубліковано 21 сер 2023
- How to inspect an electric panel with an infrared camera.
Update: UL 489 limits the allowable temperature rise above ambient to 90°F. You can find more information about this on the Schneider Electric website.
An infrared camera and checking the current draw on the neutrals is also helpful for locating incorrectly wired multiwire branch circuits (L1 & L2 on same phase, neutral carrying the sum of both ungrounded conductors). Happens more frequently than you might think, particularly when tandem breakers are added and the panel is rearranged by someone unqualified.
I am glad to see there is an actual allowable temperature rise value (90f/108f) that I can reference in my reports along with an amperage reading on the circuit. I would not report a hot spot without this info. Thanks Ruben.
Great presentation! Thank you! Useful information and clearly presented/explained. Just discovered this channel and plan to watch several more. Some of the topics I'm not interested in, alt least for now. But various problems and situations often turn up when you own and maintain property, so who knows? Ok, maybe home inspectors. LOL
The UL standard regarding temperatures for molded-case circuit breakers is UL489. This has been known for years by any good electrician or electrical engineer.
NETA table 100.18 is the standard for thermography maintenance and testing for heat.
Thanks for sharing.
What kind of camera are you using
A circuit breaker is rated at 75 degrees Celsius (167 degrees Fahrenheit). Conductors are also rated at 75 degrees Celsius - although there are now installations that can be at 90 degree Celsius (194 degrees Fahrenheit). A 20 ampere rated circuitbreaker at some installations can carry 20 amperes of current, although most installations will be limited by code to 16 amperes. When a circuit is properly installed and the circuit breaker is carrying 20 amperes, the breaker will rise in temperature to well over 100 degrees. This is not understood by many, and you would hear them say it would trip the 20 amp circuit breaker. Not so. Again, with the installation being properly installed, a 20 amp circuit breaker will not trip carrying a 20 ampere load. It will become very hot though. When you come across this situation, it is best to call a qualified electrician to trouble shoot the circuit, making sure the heat is normal and not caused by other electrical issues. Overcurrent protection can be very complex, such as rise in ambient temperatures as one example of the complexity. Your judgement sounds pretty good, except. Are properly trained to try and deal with all you are mentioning?? Leave it to the ones who have more experience, you will still be the hero. 85 degrees is not a "hot" conductor/breaker. Working in a live panel requires Safety glasses, long sleeve shirt and the proper gloves. it is an OSHA VIOLATION, NFPA 70E VIOLATION and a safety issue you may one day regret. It also tells me you are not properly trained which make you unqualified to the work. Call a licensed qualified electrician and your company will be as good as you believe it is.
Can you suggest some norm to use for such inspection ?
valuable information, appreciate the bible scripture in the background.
Circuit breakers and wiring have a maximum operating temperature that should be considered. The example I have is a 120/240V, 15A, Square D type QOT breaker that accepts 60° C (140° F ) or 75° C (167° F ) wire. There is also a full load current temperature rating molded into the case itself of 40° C (104° F ) indicating this as the maximum ambient operating temperature. When I do thermal imaging scans, I consider it a concern if there is a temperature rise over ambient of 40° C (104° F). Further, I will stop testing if the temperature reaches the temperature rating of the wire.