Yet another wire size question

[Planenutz]

I found previous garage owner wired a 220 20a outlet with 14 ga NM wire. It's about 30' from breaker to outlet. Here's the tag on the compressor. Seems to be OK at 15 amps for that distance according to the online wire size calculators.
Would you agree it's ok? I'd rather not have to pull new wire through the walls.
Thanks

 

[wyliesdiesels]

20a outlet with #14 NM is not ok.

Wire for motor circuits is sized by HP rating. Since the motor is SPL you have to compare the FLA rating to the NEC FLC chart.

That motor is about 3HP so it needs #10 NM-b or #12 THWN in pipe.

17a x 1.25 = 21.25a

 

[Shiftless]

Have you considered a surface mounted conduit installation?

By pulling a few more wires, you could use the new conduit run to not only solve your wire gauge problem for the 240V but add another 120V receptacle if you need another one somewhere in that 30 feet. A new dedicated circuit 20A duplex receptacle might be a welcomed addition.

To me, a well done conduit run in a working garage does not look out of place.

 

[nadogail]

Have you considered a surface mounted conduit installation?

By pulling a few more wires, you could use the new conduit run to not only solve your wire gauge problem for the 240V but add another 120V receptacle if you need another one somewhere in that 30 feet. A new dedicated circuit 20A duplex receptacle might be a welcomed addition.

To me, a well done conduit run in a working garage does not look out of place.

What he said.

 

[theoldwizard1]

Change the breaker to 15A.

If the motor trips the breaker, then pull new wire and go back to the 20A breaker.

 

[u2slow]

The wire can technically handle the 15A load being asked of it. After all, a compressor that charges up a tank is not a continuous load.

But for peace of mind, and to match the 20A breaker and receptacle being used, best to upgrade to #12. Code wants #12 too.

 

[Planenutz]

Alrighty. Thanks guys.

 

[mike93lx]

20a outlet with #14 NM is not ok.

Wire for motor circuits is sized by HP rating. Since the motor is SPL you have to compare the FLA rating to the NEC FLC chart.

That motor is about 3HP so it needs #10 NM-b or #12 THWN in pipe.

17a x 1.25 = 21.25a

and a 30A breaker, correct?

 

[u2slow]

and a 30A breaker, correct?

If the the OP's compressor has a 6-20P cord (much like my own 3HP/SPL unit with 16A FLA), then the manufacturer intends it for use on a 20A circuit.