Neutral Conductor as curcuit cayying

[jbolen]

When using 12/4 with ground so cord is the neutral a curuit carrying condutor and do I have to rate the cable @ 80%?

If so would I use a 20amp breaker or 15 amp breaker for this motor load?

 

[ptonsparky]

Once you say motor everything changes.

 

[roger]

Single phase, three phase, what conductors of the cable are connected to the motor?

Roger

 

[Smart $]

Need motor data also...

 

[charlie b]

When using 12/4 with ground so cord is the neutral a curuit carrying condutor and do I have to rate the cable @ 80%?

I infer that you meant to say "current carrying." Yes the neutral will have some current flowing, if there is any imbalance between the loads on the three phase conductors. But if the neutral carries that imbalance, and only that imbalance, then it does not count as a "current carrying conductor," in the context of derating when there are more than three in a cable or conduit. So if this is a motor load, and unless there are significant harmonics (not common for motors), then the neutral does not count, and you don't have to derate.