Electrical Myth
While searching through the forums recently, I came across two posts in which an old electrical myth is repeated- "Circuit breakers will trip at 80% of their rating." For any breaker which has not deg...
Forum Discussion
RickJay is correct (And yes, we're probably splitting hairs here, but the breaker by itself isn't the issue. It's the breaker mounted in an enclosure which doesn't allow it to dissipate heat effectively. Thus it's temperature rises, and the graphs by the OP predict the derating of the breaker, and now the "nominal current" may become an overload, and the trip time graph I posted above has to be revisited with the derated breaker rating. )
You must remember according to the listing the breakers are tested in free air totally different than having a panel full of breaker inclosed in a panel. I can tell you from year of experience that a multiple breaker loaded up to 80% and beyond do generate a lot of heat that will cause nuisance tripping this is why the 80% rule in the NEC
Continuous load is considered 3 hours or more.
You must remember according to the listing the breakers are tested in free air totally different than having a panel full of breaker inclosed in a panel. I can tell you from year of experience that a multiple breaker loaded up to 80% and beyond do generate a lot of heat that will cause nuisance tripping this is why the 80% rule in the NEC
Continuous load is considered 3 hours or more.
