Right Size Wire to use on breaker?

[mull982]

I have a pendent crane hoist that is rated for 4 Amps at 480V. Because of its location the only way we have avaliable to power it is with a 20A 480V breaker. The contractor supplied 16AWG wire which is rated less then 20A.

I'm telling him that he cannot use wire that is rated less than the rating on the feeder breaker to run this circuit. I believe #16 is rated for 15A which is below the rating of the breaker. Am I correct in telling him that this wire although sized ok for this load, is still not sized correctly for the avaliable breaker size?

Does it matter that this is not a continuous load but rater an intermitent non-continuous load?

 

[iwire]

Did he run 16 or 14?

Motor loads follow different rules and 14 is likely fine.

If it was 16 AWG you should point out 310.5 to him.

310.5 shows 14 AWG as the minimum size for power and lighting conductors unless specifically allowed elsewhere in the NEC

 

[mull982]

Did he run 16 or 14?

Motor loads follow different rules and 14 is likely fine.

If it was 16 AWG you should point out 310.5 to him.

310.5 shows 14 AWG as the minimum size for power and lighting conductors unless specifically allowed elsewhere in the NEC

He ran #16 for this crane hoist, so it sounds like you are saying ( and the NEC is saying) that this #16 is too small. Would this crane hoist be considered a motor load?

In 310.5 the minimum size rating of #14 I'm assuming refers to general wiring for power and lighting and does not include control wiring which I have seen run with #16 before.

 

[jatrottpe]

Where #16 is allowed per NEC it is limited to 10amps (ie 240.4 D)

 

[iwire]

Would this crane hoist be considered a motor load?

In my opinion yes.

In 310.5 the minimum size rating of #14 I'm assuming refers to general wiring for power and lighting and does not include control wiring which I have seen run with #16 before.[/QUOTE]

Control wiring is covered in 725 and 725.27 gives permission for smaller conductors then 14 AWG.