jcgjupiter
Member
On a motor feeder OCP question that list 4 or 5 motor of varying voltages and horsepower, including amps. The question says use inverse time breaker.
If that is all the info given, how do you know the "largest rating or setting of the branch circuit short circuit and ground fault protection device for any motor supplied by the feeder"
because they only say use an inverse time breaker for the feeder, they don't say use one for each individual motor. That could be a different rating depending whether it was a fuse, breaker, etc.
Are you to assume that because they say to use an inverse time breaker for the feeder OCP that you are to do your calcs using an inverse time breaker for the branch circuit for the largest amp motor.
This has me confused.
Any advice?
If that is all the info given, how do you know the "largest rating or setting of the branch circuit short circuit and ground fault protection device for any motor supplied by the feeder"
because they only say use an inverse time breaker for the feeder, they don't say use one for each individual motor. That could be a different rating depending whether it was a fuse, breaker, etc.
Are you to assume that because they say to use an inverse time breaker for the feeder OCP that you are to do your calcs using an inverse time breaker for the branch circuit for the largest amp motor.
This has me confused.
Any advice?