electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
...as in trip too soon or easily? This is one of those things people ask or say a lot, but I can't recall actually seeing a single instance in my career.
...as in trip too soon or easily? This is one of those things people ask or say a lot, but I can't recall actually seeing a single instance in my career.
Yes they do. I have replaced at least 2 main 200 amp breakers one of which was tripping with less than a 60 amp load
...
A FOP test will show this.
FOP = Fall Of PotentialSorry, I’m having a hard time figuring this one out. What’s an FOP test?
Were they old or relatively new?
Sorry, I’m having a hard time figuring this one out. What’s an FOP test?
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Anything that creates undesired heat within is going to increase the possibility of tripping on thermal, can even be heat that originates at a termination or bus connection and is conducted to interior of the unit.
Old ones but I have seen some not function right out of the box.
I could see that, but what isn't clear to me is how the mag function would go bad to make it trip early.
That would more likely be from mechanical wear from being used daily as a switch rather than just age.I could see that, but what isn't clear to me is how the mag function would go bad to make it trip early.
And could make it trip at higher or lower fault current depending on wear conditions I would think, or at very least affect clearing time compared to when it was new.That would more likely be from mechanical wear from being used daily as a switch rather than just age.
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FOP = Fall Of Potential
It means measuring the voltage between the line and load terminal of one pole at a time. You're looking for voltage drop where there shouldn't be any. In theory, there should be zero volts across a closed switch or breaker.
I would check the line current with a clamp-on ammeter.
There are TOO MANY, WAY TOO MANY ACRONYMS, and they are becoming bothersome for this reason. There are other aspects about them which make them even more distasteful that there is no need to go into. Some of the exact same ones cross over into completely different trades and mean different things.
There needs to be as master list on the forum possibly.