sears motor help

[wazzabie]

The data plate on the motor is

model C-140-3013
5KCR48SR59W
RPM 3450
V 230
A 13.1
Code 839M
PC B1037
40C AMB CL

It is on s sears 5hp air compressor. The plug on the compressor is for a nema 6-20.

Do i then need a 20 amp breaker?

I currently have a 30 amp breaker 10 gauge wire 240v hooked up to a 200amp service panel running to the location where I would like to have the air compressor. Can I install a nema 6-20 oulet on this run?

 

[wyliesdiesels]

Thats not a true 5HP motor. Amps are too low.

Its more like a 2 or 3HP motor.

Nema 6-20p will be fine with #12 wire. Breaker needs to be 20a.

Motor circuit wiring is sized @ 125% of NEC FLC.

Breaker can be max 250% of NEC FLC.

EDIT: I really shouldnt type up technical comments when Im half awake. If u use a 6-20P and r, then the breaker needs to be 20a.

 

[wazzabie]

Is it ok if in install a Nema 6-20 outlet on a 30amp breaker?

 

[pattenp]

Is it ok if in install a Nema 6-20 outlet on a 30amp breaker?

No, it's not okay.

 

[pattenp]

Something in this size will have, or should have, thermal overload protection in the motor. 30A breaker is fine with 6-20 outlet.

It's not fine.

 

[md21722]

Yeah, I just realized we were talking breakers vs outlets so I deleted my message before even seeing your response

 

[pattenp]

Thats not a true 5HP motor. Amps are too low.

Its more like a 2 or 3HP motor.

Nema 6-20p will be fine with #12 wire. Breaker can be 20a or 30a.

Motor circuit wiring is sized @ 125% of NEC FLC.

Breaker can be max 250% of NEC FLC.

That's okay for a hardwired motor circuit, but not a circuit with an outlet.

Read NEC 430.42(C).

 

[wazzabie]

so do i need a 15amp or 20amp breaker?

 

[pattenp]

so do i need a 15amp or 20amp breaker?

If using a 20A outlet you can have a breaker no larger than 20A and the wire can be no smaller than #12. So you need a 20A circuit for your compressor.

 

[Gttrucker]

Wyleisdeisels is correct. That is not a true 5hp. If I recall correctly 1 HP equals about 750 watts, so 5 HP is 3750 watts. At 230 that's 16amps.
So your fine with 12 gauge line and 20 amp connectors even if it was a true 5hp. I always wonder how they come up with HP ratings on motors. Air compressors are always over rating their power to sell their stuff.

A note on the cord. I see a similar problem with extension cords. They often have more resistance than the rated gauge should have, so if your planning to buy a coed and cut the end off (as opposed to just buying cable) then I'd get a 10 gauge cord 'cuz I don't trust their numbers.

 

[Gttrucker]

If this is a stationary compressor you could just skip the plugs and cable and hard wire it direct with 12/3 armored cable. It's fairly cheap and handy to have on hand for running extra outlets etc.

 

[pattenp]

....

So your fine with 12 gauge line and 20 amp connectors even if it was a true 5hp. ......

By NEC motor rules that is not fine. For sizing conductors for 5HP you need to use 28A as the amperage. Which is 35A conductors (28A X 125%).

 

[Gttrucker]

pattenp is right. A true 5hp should have a 30amp/10ga line ... hmmm but this is not really a 5hp motor it's a 13amp motor so 12/3 should be fine.

 

[wazzabie]

pattenp is right. A true 5hp should have a 30amp/10ga line ... hmmm but this is not really a 5hp motor it's a 13amp motor so 12/3 should be fine.

I currently have a 30amp/19 gauge line going to the location. If I put the 20gauge outlet on the line and only used it to connect the air compressor would that be ok?

Thanks for the help

 

[pattenp]

I currently have a 30amp/19 gauge line going to the location. If I put the 20gauge outlet on the line and only used it to connect the air compressor would that be ok?

Thanks for the help

If you have #10 wire you can use a 20 amp breaker and a 20 amp outlet. It's going to be tough connecting #10 to a 20A outlet and getting it all back into a standard single box if that's what you have. You should not use a 30A breaker.

 

[wyliesdiesels]

That's okay for a hardwired motor circuit, but not a circuit with an outlet.

Read NEC 430.42(C).

True.

I typed my comment while i was half awake...

 

[wyliesdiesels]

I currently have a 30amp/19 gauge line going to the location. If I put the 20gauge outlet on the line and only used it to connect the air compressor would that be ok?

Thanks for the help

19 gauge wire? Thats really small.

I hope u meant 10 gauge...