AnsweredAssumed Answered

NEC 250.122(B)

Question asked by dmatern on Nov 20, 2019
Latest reply on Nov 25, 2019 by dmatern

In regards to NEC 2014 250.122(B). [Conductors are based on THWN-2, 75 degree terminations and 86 degree F ambient temperature]:

 

Question/Condition 1: Engineer selects (1) run of (4) #350 KCMIL copper conductors and (1) #3 EGC for a feeder and connects to 350 amp circuit breaker (OCPD). Neutral in this case is not a current carrying conductor. Load is 307 amps, non-continuous. Is this correct?

 

Question/Condition 2: Engineer selects (1) run of (4) #400 KCMIL copper conductors and (1) #3 EGC for a feeder and connects to 350 amp circuit breaker (OCPD). Load is 315 amps, non-continuous. Neutral in this case is not a current carrying conductor. Is this correct?

Outcomes