ceb58
Senior Member
- Location
- Raeford, NC
I have been having a discussion with some others on the rules for sizing conductors on a generator. Looking for more opinions.
The situation: Standby generator with a built in 50 amp breaker.
My opinion is that you must size the conductors for the overcurrent device per 240.4 which would be #8 Cu.
Others have an opinion that you can size the conductors per the name plate which is lower in ampacity than the breaker. In this case it is 45.8 ( on LP gas). They are saying that because the controller limits the output they can use the exception to 445.13 and size per name plate. ( in this case it would be #8 ether way)
My argument against this is that the conductors must be sized to the breaker because the generator is capable of exceeding the name plate rating on equipment start ups. But my main argument is because the generator has a built in breaker 445.13 is not applicable, there for you cannot use an exception to a code rule that doesn't apply to the situation.
Comments?
The situation: Standby generator with a built in 50 amp breaker.
My opinion is that you must size the conductors for the overcurrent device per 240.4 which would be #8 Cu.
Others have an opinion that you can size the conductors per the name plate which is lower in ampacity than the breaker. In this case it is 45.8 ( on LP gas). They are saying that because the controller limits the output they can use the exception to 445.13 and size per name plate. ( in this case it would be #8 ether way)
My argument against this is that the conductors must be sized to the breaker because the generator is capable of exceeding the name plate rating on equipment start ups. But my main argument is because the generator has a built in breaker 445.13 is not applicable, there for you cannot use an exception to a code rule that doesn't apply to the situation.
Comments?