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Air compressor circuit breaker size?

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wazzabie

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What size circuit breaker should I use? Also I have a 50amp 25ft extension cord I'm going to use. The electrical panel is in the garage and I can add a double pole. This is a portable compressor.

The motor on the compressor is:
GE MOTORS
Model: 5KCR48SR59GW
PART NO: C-MO-3013
V: 230
A: 13-1
HZ: 60
RPM: 3450 PH1
PC: B1037
 
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JohnX14

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Bert_ said:
False. This is a motor. Article 430 tells you how to size the wire and the breaker.

I would probably run min #12 and put it on a 30A
Click to expand...
I think OP is installing a plug to run a cord to the portable compressor. I wouldn't put a #12 on a 30 in this case. And at 13.1 amps, a 20A 240V receptacle should be fine.
 
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wazzabie

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The Metric System said:
Breakers are selected based on conductor size, not the equipment being run.

What size wire do you have in the wall between the panel and the outlet?
Click to expand...
8 gauge Romex. The main panel box is in the garage and I have the outlet 2 feet from the panel. I can run any circuit breaker up to 50amp.
 
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mm08822

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wazzabie said:
5hp
Click to expand...
At 13.1A, the "5HP" you see somewhere is 5HP SPL as in NOT 5 hp. It's more like 3 hp, maybe less.

You need a minimum conductor ampacity of 1.25 x 13.1 = 16.4A >> 20amps>> #12cu.

What receptacle will you be using? Does the comp have a cord and plug now?

For this motor, on a motor circuit, the max size cb is 2.5 x 13.1 = 32.75amps>>>35a 2 pole cb.

If this circuit will have a standard receptacle, I would look into 20a "high magnetic" cb's. What is the panel mfr?

If larger conductors are used, it will require a higher ampacity recept just to be able to terminate the wires.
 
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sparky 1971

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Those are the same spec's as my compressor and pretty much every other 60 gallon with a SPL (3ish HP) motor on the planet. Mine runs on #12's with a 30 amp breaker but I know a few people that have theirs plugged into a 20 amp 240 volt circuit.
 
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BurtEggley

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we are discussing a 240V circuit with an extension cord?

What is the brand and model of the air compressor?
 
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wazzabie

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mm08822 said:
At 13.1A, the "5HP" you see somewhere is 5HP SPL as in NOT 5 hp. It's more like 3 hp, maybe less.

You need a minimum conductor ampacity of 1.25 x 13.1 = 16.4A >> 20amps>> #12cu.

What receptacle will you be using? Does the comp have a cord and plug now?

For this motor, on a motor circuit, the max size cb is 2.5 x 13.1 = 32.75amps>>>35a 2 pole cb.

If this circuit will have a standard receptacle, I would look into 20a "high magnetic" cb's. What is the panel mfr?

If larger conductors are used, it will require a higher ampacity recept just to be able to terminate the wires.
Click to expand...
50amp welder outlet. I need to add a circuit breaker at the panel. Has a run about 2ft away from the main panel.
 
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BurtEggley

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should be a white label on the rail. If it looks like this, here a typical manual on one made by Devilbiss. Open it in a PDF reader, go to the parts about 1/2 the way thru and see if it looks like yours. That said, both craftsman that I have can be wired for 120v or 240v. The breaker specs are in the manual. Breaker and wires should match.
 

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lolaetype

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This might be helpful:

Breaker and Wire Size Guidelines Based on HP and Voltage

Breaker and Wire Size Guidelines General Guidelines to Determine Breaker and Wire Size for Air Compressors. Based on NEC. Local Codes may differ.
www.compressorpros.com www.compressorpros.com

And, FWIW AI says:

The GE Motors 5KCR48SR59GW is a 220V/230V motor (often used in 5HP air compressors) that typically requires a 30-amp, double-pole circuit breaker. It should be wired using 10 AWG wire for the load. Ensure the breaker matches your specific service panel brand (e.g., GE, or compatible Eaton CL or ABB breakers).

Key Considerations:
  • Breaker Type: 2-pole (Double-pole) circuit breaker.
  • Amperage: 30 Amp (Standard for 5HP compressor motors, check nameplate for exact full-load amps).
  • Voltage: 220V-240V.
  • Wire Size: 10-gauge wire is generally required.
 
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u2slow

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wazzabie said:
What size circuit breaker should I use? Also I have a 50amp 25ft extension cord I'm going to use. The electrical panel is in the garage and I can add a double pole. This is a portable compressor.

The motor on the compressor is:
GE MOTORS
Model: 5KCR48SR59GW
PART NO: C-MO-3013
V: 230
A: 13-1
HZ: 60
RPM: 3450 PH1
PC: B1037
Click to expand...

My speedaire is similar... 15A/240V rated and has successfully run on #12/20A circuits for 25ish years. The factory cord plug is a 6-20P.
 
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beltfeed

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Sharing a common breaker for two different loads has its short comings (safety issues). Like others have said the load specs for the welder would help.
 
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alfredeneuman

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If you have room in the panel, just install another breaker.
At only 2' from the panel, just ignore (or use) the welder outlet.
Buy a 30A breaker and #10 wire. Install a 6-30 (30A/250V) outlet.
 
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wazzabie

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Update: I found the manual for this air compressor. The manual calls for a min 15 amp circuit and a fusetron type t fuse. From the panel I have this dedicated circuit: 30amp 8/2 Romex, 2 pole type O interrupting rating 10,000 120/240v Siemens L-5538 E82615 circuit breaker. https://www.homedepot.com/p/Siemens-20-Amp-Double-Pole-Type-QP-Circuit-Breaker-Q220U/100074746 I suspect the plug on the air compressor is rated only for 15 amps. If I change out the plug can I use this air compressor on the 30amp circuit? The model number is 919.176951 Do I need to change the circuit breaker to a fusetron type t fuse?

1774126947466.png
 
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wazzabie

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wazzabie said:
correction 6 gauge wire on a 50 amp outlet.
Click to expand...
I have two dedicated circuits from the panel that run about 3 feet in length: 1. 8/2 romex on 240v 30 amp Siemens circuit breaker 2. 6/2 Romex on 240v 50 amp Siemens circuit breaker
 
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u2slow

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also in the manual:
Screenshot_20260321-143652-478.png

one more time.... wire in a 6-20R on a 20A 2pole breaker with #12 wire. Plug your machine in.
 
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wazzabie

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The extension wire that I would like to use with the air compressor is a Direct Wire 25' 220 Volt 50 Amp Heavy Duty 8/3 Welder Extension Cord MIG TIG. https://ramweldingsupply.com/p/direct-wire-cable-8-3-heavy-duty-welding-machine-extension-cord/

If I change out the cord on the air compressor to fit the end of my welding extension cord and then plug this into the 30amp dedicated 240v circuit would this be ok for the air compressor? I just need to use it temporary for about a week.
 
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wyliesdiesels

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wazzabie said:
Update: I found the manual for this air compressor. The manual calls for a min 15 amp circuit and a fusetron type t fuse. From the panel I have this dedicated circuit: 30amp 8/2 Romex, 2 pole type O interrupting rating 10,000 120/240v Siemens L-5538 E82615 circuit breaker. https://www.homedepot.com/p/Siemens-20-Amp-Double-Pole-Type-QP-Circuit-Breaker-Q220U/100074746 I suspect the plug on the air compressor is rated only for 15 amps. If I change out the plug can I use this air compressor on the 30amp circuit? The model number is 919.176951 Do I need to change the circuit breaker to a fusetron type t fuse?

1774126947466.png
Click to expand...

If that motor is truly rated for 5HP, there is no way it could go on a 15a protected circuit. it would blow the fuse. The FLC chart amperage for 5HP is 28a and typical 5hp motors have an FLA of 20-23a 240v.

post a pic of the motor nameplate. if the HP is listed as SPL or special, and/or the FLA is listed as 15a, then the 5HP rating in the manual is bogus and the motor is closer to 3HP rating....

FYI- the plug would need to be rated for the HP rating of the motor if you change it from factory. There are no standard NEMA plugs and receptacles that are rated for more than about 3hp....
 
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wyliesdiesels

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u2slow said:
also in the manual:
Screenshot_20260321-143652-478.png

one more time.... wire in a 6-20R on a 20A 2pole breaker with #12 wire. Plug your machine in.
Click to expand...

not if the motor is rated for 5HP. that would be incorrect. wire for motor circuits is required to be rated 125% of FLC table current. for 5HP that is 25 rated wire.... and a nema 6-20R is not rated for 5HP.... the devil is in the details...
 
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wazzabie

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u2slow said:
also in the manual:
Screenshot_20260321-143652-478.png

one more time.... wire in a 6-20R on a 20A 2pole breaker with #12 wire. Plug your machine in.
Click to expand...
Ok I'll wire a new circuit. I found a spare 20A 2 pole breaker and 20a-250v outlet. I have some spare 10/3 Romex. Can I use this wire rather then the #12 wire? Also this new outlet will be the 4th dedicated circuit running from the main panel. Is there a limit on how many circuits and outlets I can have next to the main panel? With this new run I will have 30amp 220v, 50amp 220v, 20amp 120v and 20 amp 220v.
 
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wazzabie

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wyliesdiesels said:
If that motor is truly rated for 5HP, there is no way it could go on a 15a protected circuit. it would blow the fuse. The FLC chart amperage for 5HP is 28a and typical 5hp motors have an FLA of 20-23a 240v.

post a pic of the motor nameplate. if the HP is listed as SPL or special, and/or the FLA is listed as 15a, then the 5HP rating in the manual is bogus and the motor is closer to 3HP rating....

FYI- the plug would need to be rated for the HP rating of the motor if you change it from factory. There are no standard NEMA plugs and receptacles that are rated for more than about 3hp....
Click to expand...
1774135002570.png1774135122081.png
 
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u2slow

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#10 should work fine. In case the receptacle terminals arent rated for #10, pigtail on #12.

Also, the HP on the motor label is blank. The 5HP on the craftsman label is fiction.
 
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u2slow

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wyliesdiesels said:
not if the motor is rated for 5HP. that would be incorrect. wire for motor circuits is required to be rated 125% of FLC table current. for 5HP that is 25 rated wire.... and a nema 6-20R is not rated for 5HP.... the devil is in the details...
Click to expand...

The machine isnt rated for 5hp when it comes with a 15-20A factory cord plug.
 
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wazzabie

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1774137278768.png Actually I may need to get a GFCI. This will be in the garage. The other outlets I wired years ago for welders are not GFCI.
 
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