In response to the compressor popping breakers…

compressor popping breakers
(Last Updated On: August 1, 2019)

Question: When I try to use my compressor, it will run for about two seconds the trip the electrical breaker that it is plugged into. I have tried four different circuits with the same results. What can I do to remedy this problem?

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Answer:

That you have tried four different electrical supply circuits with the same results clearly indicates a problem with your compressor and not the supply circuit.

The breaker trips because the compressor circuit is drawing more amperage than the circuit can provide, and that’s caused by a fault of some sort in the compressor itself.

I think we can assume that there’s not a short in the power supply to the compressor (power cord) as if there were, the breaker would pop instantly.

compressor popping breakers

The compressor turns on when you plug it in because the pressure in the tank is below the pressure switch cut-in pressure setting.

Since the compressor pressure switch reacts to system pressure, in your case it’s already switched and “calling” for power to flow to the electric motor when you plug the compressor in, since you indicate that the compressor starts and runs for two seconds before popping the breaker.

Now, does the motor actually start, or does it just try to start? I ask this because if your unloader valve hasn’t  “dumped” the air over the piston when the compressor last stopped, that trapped air might overload the motor to the point that the breaker pops.

It seems to me that your pressure switch is OK, since if there were a short in it, the breaker would pop immediately you plugged in the power cord, not wait 2 seconds.

That your compressor starts and runs for two seconds suggests that your motor capacitor is OK, else the motor wouldn’t start at all.

I think you’ve got a motor problem.

Though it could be the motor itself that’s failing, drawing too much power as it tries to start and overcome whatever is ailing it, it could also be that there’s a mechanical issue with the compressor power train, and that mechanical issue is overloading the motor shaft, creating additional load on the motor and starting circuit, and forcing the motor to draw too much amperage which pops the breaker.

So, if the compressor unloaded the last time it ran (it goes psssshhhttt for a second or so to let the air out over the piston when it stops), and if the motor actually starts and runs for 2 seconds, and assuming this is a new condition and the compressor ran with these electrical supplies before (the motor amperage normally doesn’t exceed the circuit) then your problem is likely from the motor to the actual compressor pump, somewhere in there.

 

Compressor Popping Breakers

Your compressor is popping the breaker as something in it, or in the circuit, is pulling more amps than the breaker can handle. That it’s popping is a good thing, as it’s preventing a bigger problem in your house or shop electrical system.

popping breakers

If you have eliminated a ground fault or short in the power cord, then the next thing to look at in the compressor electrical circuit is the pressure switch.

It reacts to pressure in the compressor system, turning the power on when the pressure falls to the cut-in point, and turning the power to the compressor motor back off again when pressure in the system reaches the cut-out high pressure setting.

It’s my guess that this may be your problem. It may have failed and in the process created a short.

Since it’s a lower cost fix to change the pressure switch than the motor, may I suggest you do that? Worst case scenario of changing the pressure switch doesn’t solve the problem is that you’ll then have a spare on the shelf.

Hope this helps. Let us know the resolution, would you?

Hello, I am Bill, the Compressed-Air-Man. I have years of experience in industrial and residential compressed air applications, air compressors and general pneumatics. I created this site to help professionals, students, and DIYers understand and properly implement and maintain compress3ed air systems.

2 COMMENTS

  1. Thanks Bill! Your readers can search our site too. The aluminum tank compressor I referenced in my post was discussed in a podcast last fall.

  2. Bill – This is a very thorough answer. I had the same issue with an older compressor. The compressor was no an oil lubed model and the mechanical bits just got to a point where there was too much resistance and the motor drew too much juice on startup and it would trip the breaker. It was an auction find compressor. i did attempt to fix it but never found the exact problem. It was likely corrosion in or around the pump. My ‘solution’ was a replacement. I got a new contractor model, oil lubed, with an aluminum tank. It works great with nailers but doesn’t cut it with some things like grinders, impact wrenches, cut-off tools, etc. I knew this going in. Anyway – thanks for an informative post.

    Bill responds…

    Hello Handyguys, and thanks very much for your kind comments.

    For the other folks that read this, visit the HandyGuys site. It’s worthwhile. Here’s the URL: http://www.handyguyspodcast.com

    Cheers,

    Bill

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