Breakers after faults

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mdshunk said:
I guess you'll have to wait for one of the NETA guys to chime in, but that one is real borderline, in my opinion. Not a good candidate for rebuilding, and not small enough to replace "just because". I'd really like to know what the NETA guys use as their guideline on breakers that have taken one or several bolted faults.
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Ding Ding

Yep thats borderline, not worth having it tested, costs as much to test it as to replace it, we dont rebuild anything less than 400A unless it is old and rare.
 
zog said:
Do you make these specs up as you go along???
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that was in a pocket guide for troubleshooting breakers. thats the way i do it for residental breakers. but usually the 30mv is just a guideline. i usually compare the questionable breaker to other known good breakers in the panel
 
electricalperson said:
that was in a pocket guide for troubleshooting breakers. thats the way i do it for residental breakers. but usually the 30mv is just a guideline. i usually compare the questionable breaker to other known good breakers in the panel
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I suppose testing anything on a residential breaker is going above the call of duty, thought were were talking 480V breakers.
 
zog said:
I suppose testing anything on a residential breaker is going above the call of duty, thought were were talking 480V breakers.
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i mean, if a breaker in someones house is tripping and you cant really find a problem with the circuit or loads you can test it by using the FOP method. im not sure how to test larger breakers without spending a lot of money on a circuit breaker testing machine or a data logger machine
 
At a minimum if you think a residential has opened under a fault, with the CB off/open megger from line to load, pole to pole. Then perform a FOP test.
 
BackInTheHabit said:
Got a picture of a $5000.00 breaker?
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I used to have one on my dash board as a paper-wieght after a demo job - until I got around to selling it. :grin: (For a fraction of that - but hey - it was free...)
 
A the CB I posted cost $7,800.00.

Pass rated current through breaker, measure voltage drop across closed contacts, < 30 mV =~ good.
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You are not using this as a bench mark for all CB's, are you?
 
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