OT--Air Compressor tripping breaker.

Jiles · Sep 26, 2014

I have a Kobalt 32gal. 2HP air compressor and it will occasionally trip my 20A breaker. It trips when it is running and never at startup. Like I stated, it trips sometimes, like once in five runnings. It unloads as it should. I rewired to another breaker and I have checked all connections on the circuit.
The motor has two capacitors mounted on top and it can be wired for 220V instead of 110V.
Would someone advise me as what to check and would I be better off running on 220?

Steve@Advance · Sep 26, 2014

If it's a true 2 HP motor, it has a right to trip! It will pull 24 amps on 120v. Yes you would be much better to wire it to 220v. Need a double 20a breaker, #12 wire.

Now some of the compressors from a few years back were over rated on horsepower. Look at the plate on the motor. It will have "FLA xx amps at low voltage". If that rating is down around 18 amps or so, it shouldn't be tripping a 20a breaker. (Still better to run on 220v) Could be the breaker is getting weak from running near it's capacity, could be a loose connection, an intermittent short.

Check for the obvious first. Another place the motor can have a short is under the bell where the centrifugal switch is. If the wires weren't routed properly they can rub against the moving parts inside the motor.

jeffcat · Sep 26, 2014

I would add, rewire to 240. Start better, run better, less power useage, and less wear and tear on the motor. I had a problem a couple of weeks ago with a loose ground connection. Did the trip trick once in awhile.

Brown Swiss · Sep 26, 2014

I advise to check the compressor, change the oil in
it and see what the old oil looks like! Or could be
bearings in the motor!

John T · Sep 26, 2014

Sounds like the thermal portion of that 20 amp single pole breaker is whats tripping. When I designed I wouldn't allow anything over 16 amps (80% of 20) continuous when using 12 Gauge 20 amp rated wire.

YES you would be better off operating it at 240 volts if its a dual voltage motor. All it takes is a 240 volt 2 Pole Breaker in your panel assuming you have the spaces to mount one. Then its just 2 Hots (L1 & L2) plus the Green/Bare Equipment Grounding Conductor to your compressor. If you already have that 3 conductor 12 Gauge wire to the unit it can still suffice for the 240 volt operation....

John T

IH2444 · Sep 26, 2014

(quoted from post at 15:05:46 09/26/14) I have a Kobalt 32gal. 2HP air compressor and it will occasionally trip my 20A breaker. It trips when it is running and never at startup. Like I stated, it trips sometimes, like once in five runnings. It unloads as it should. I rewired to another breaker and I have checked all connections on the circuit.
The motor has two capacitors mounted on top and it can be wired for 220V instead of 110V.
Would someone advise me as what to check and would I be better off running on 220?

How long is your wires from your breaker box to your compressor? And is this in a sub-panel wired from the main breaker panel? If so how far is that by wire? And what size wires are feeding the sub panel. Your problem could be excessive voltage drop which will cause excessive current.

Russ from MN · Sep 26, 2014

I think anything that can be run on 220 should be,
many reasons it's better.

Jiles · Sep 26, 2014

[b:19a60c8f73]How long is your wires from your breaker box to your compressor? And is this in a sub-panel wired from the main breaker panel? If so how far is that by wire? And what size wires are feeding the sub panel.

[/b:19a60c8f73]Approximately 20' total run from main panel with #12 and 18 foot from sub. which is wired with #8 mounted app. one foot from MP.
Sub panel also feeds three more circuits of lights.

I am afraid I may have a bad motor because it has been working for 10 years with no problems but this breaker tripping started first of this year and is getting more frequent.
Most valuable tool I have-use it every day!

Ford and Gravely · Sep 26, 2014

Possibly the running capacitor bad.

Jiles · Sep 26, 2014

(quoted from post at 01:17:35 09/27/14) Possibly the running capacitor bad.

How do I check that?

David G · Sep 26, 2014

I agree with the others, a 2HP motor should warm up and trip a 20A breaker.

Jiles · Sep 26, 2014

(quoted from post at 01:43:34 09/27/14) I agree with the others, a 2HP motor should warm up and trip a 20A breaker.

Owners manual advises to use a 20A breaker. Running HP is 1.8

Mark - IN. · Sep 26, 2014

I had a problem like that once, and the solution in my case was simple. I was using the compressor outside while reroofing. The 100' extension cord that I was using was way too small guage, so the compressor motor was heating up and requiring extra current to run. Kept popping the breaker as well. I couldn't figure out until I grabbed the compressor motor and nearly burned my hands off. Plugged its short heavier guaged cord directly into a socket and switched to a 100' hose, no more problems ever again. That's what happened in my case.

Good luck.

Mark

OT--Air Compressor tripping breaker.

Jiles

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Steve@Advance

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jeffcat

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Brown Swiss

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John T

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IH2444

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Russ from MN

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Jiles

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Ford and Gravely

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Jiles

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David G

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Jiles

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Mark - IN.

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