I know how to use the wire sizing tables, but I'm unclear on how to size wire before a breaker, and when the panel has no main breaker.
For example, If I have a temp power service panel that is rated for 125 amps, and does not have a master breaker, and has 6 breaker slots, and I plan to install one 20 amp and one 30 amp breaker, do I size the service entrance wire (from weather head to meter to panel) based on:
a. 50 Amps, the sum of the intended number of breakers
b. 125 Amps, because that is what the panel is rated for
c. Some other calculation?
I've been reading through the NEC on service entrances, and the sizing recommendations are for things like schools, hospitals, houses, farms, etc, but doesn't (at least that I can find) clearly state the service wire sizing rules for a temp pole. Normally you would base this off of the main breaker size, but since temp poles don't have main breakers is it the sum of all breakers, or the max rating of the bus?
Does anyone know what code section covers this?
Best Answer
According to the National Electrical Code 2017, the service-entrance conductors should be sized based on the loads being served.