My air compressor makes a humming sound when I first turn it on then shuts off.?

Question

The motor will not turn over to fill the container with pressurized air. It was working fine prior to this morning. It throws the switch on the surge protector after the few seconds of humming stops. Does anyone have any ideas what the problem might be? Thanks for the advise.

Answer 1

Check the motor start capacitor. If it is disconnected or has failed the motor won't know what direction to turn.
If you can safely give the motor a nudge to start rotating it should continue to spin.

Answer 2

Just one other possibility. My air compressor did something like this last fall. I checked all of the wiring from the plug, to the motor. What I found was the black hot wire, and the white neutral wire in the control unit that controls pressure were routed over one another, and over the 15 years I owned the compressor they had fused together and were creating a direct short.

Luckily it was the wire between this pressure control unit and the motor, and I had enough slack in it to cut out the bad part and hook it back up to the terminal block.

It worked through 3 weeks of a flooring installation job after the fix.

It was tripping the breaker though.

My motto is always check the cheapest things first!

Answer 3

You probably have a bad shorted or burned out STARTER winding in the motor.

However, you might have a defective "capacator switch" or a broken wire to the "capacator' Look on top of the motor there should be a small round long case on there and remove those two screws and under that is the capacator. Make sure those wires havent come off or broken. Somehow get the capacator checked or replace it is a possiblity its bad too.

Probably a capacator start motor with a cutout switch is what you have.

Answer 4

Almost all the answers are good, but I'd like to offer one more possibility. You're having the same problem I had many years ago with a new Sears air compressor. I took mine back for repair under warranty, but the problem soon returned. I eventually discovered a loose connection inside the motor. One five cent wire nut later and I was back in business

Answer 5

When was the last time you checked the compressor oil and/ or changed it? You may have seized the compressor piston. Unplug the compressor and try turning the pulley on the compressor. If it won't turn then it is the compressor. If not then it is the motor or capacitor combination in which case refer to the man that works for Granger, they have the repair parts.

Answer 6

I notice no one has mentioned extionsion cords.... If you are using an extension cord, it cuts down on the available amps for your compressor (the longer the cord, the fewer amps available)... and a compressor that is rated at 15 amps, for example, will not turn over, when only receiving 10 amps.

You could spend over $100 to buy an extremely heavy duty cord to reach where you want... but...the best solution is to get rid of the extension cord, and use more air hose. (something most air compressor manufacturers recommend anyway)

Good Luck

Answer 7

could be your motor has a bad capacitor on it....it most likely has two... one is a run capacitor, one is a start capacitor.... there should be two covers on the motor.... maybe about 3-4 inches long... remove the screws and disconnect the wires.... take both capacitors (if you have two) to an electrical supply company... i work for a company called grainger, we sell them..... you can find a local grainger at www.grainger.com we can test the capacitors to see if they are bad.... they arent too expensive, depends on the microferret rating, they could run you anywhere from 5-20 bucks a piece..... if your capacitors are good, then the motor itelf could be bad.... if you have a transfer switch, the thermal units in the switch could be bad , or the switch itself could be shot.... even worse your compressor pump could be shot...considering the motor is humming though, sounds like a capacitor to me..... good luck!!!

Answer 8

before everything have you ever replaced your air filter out interior the previous 30 days? If no longer shall we start up there. substitute the filter out. next re-set the breakers for the indoor and outdoors unit. Now turn on the unit on the thermostat, decrease the temperture stting, set it to vehicle and funky.Now bypass to the exterior unit and notice no rely if it extremely is on. collectively as there attain down and experience of the huge copper freon line (no longer the small one) it would be getting chilly to touch. If no longer then i might say which you're low on freon. no rely if it extremely is chilly, take a backyard hose and rinse off the out section condenser coils.

Answer 9

you might want to check if the piston is locked up to do this you can try and turn it over by hand with it unpluged.If it does your electric motor is burned up.

Answer 10

You are overheating the circut. Plug it directly into the outlet, and make sure nothing else that is plugged into the same circut that is drawing power -refridge-microwave etc..