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Are you having issues with your air compressor motor sparking and smoking? Here are some examples of why this could be happening to you and how to fix it.
Table of Contents
- Why is my Motor Sparking and Smoking?
- Reader Comments & Responses
Why is my Motor Sparking and Smoking?
There are a few different reasons as to why these could be happening, and these are due to:
- amarture windings
- commutator pads
I will briefly discuss each and how you can resolve this issue to stop the sparking and smoking on your compressor.
Some sparking can be normal on an air compressor, but excessive sparking is not. The sparking more often than not tends to be a symptom of a badly worn down brush and could potentially go away when it’s replaced with a new part.
If only one of the brushes is worn down, I would still advise replacing both of the brushes at the same time.
If the sparking is excessively bad, it may be worth checking if the armature windings have gone open circuit. To test this follow these simple steps:
- remove the brushes
- pick two commutator pads (rectangular copper blocks the brushes rub on) opposite each other and measure
- move onto next two and repeat until you have measured them all
You ideally want the readings to be all close to each other, if they vary significantly then you have a winding that is an open circuit, causing the significant sparking.
As mentioned, the commutator pads are the rectangular copper blocks that the brushes rub onto. If you have damaged brushes, they can cause the commutator pads to have small groves in them from the brushes digging in. Replacing just the brushes may not solve the problem as these small groves may still cause the sparkage.
It is therefore advised that you seek to have the commutator reconditioned.
If you’re wondering how to size a motor pulley, we have a guide with a worked example on our site!
Reader Comments & Responses
Compressor Motor Was Sparking and Smoking
I started the compressor and the motor was sparking, considerably, and when i shut it off it was smoking.
I plugged the air compressor in and there were considerable amount of sparks around the air cooling fan wheel. I turned it off and it was smoking.
What can the issue possibly be? How can I fix it or does a professional need to repair it?” so says Gary of Effingham Ill.
Smoke compressor motor after sparks
Sounds like burnt/burning brushes but cannot be sure as I have no idea of the compressor make or model.
You need to figure out what kind of motor (manufacturer) to try to get replacements.
Or, take it to a motor shop.
At least, let us know the make and model and maybe upload a photo or two?
Another compressor motor sparking.
This one from Barry, and he’s added a short .mov of it which you can see below.
I reviewed the video clip and it sure looks like the brushes are going. Your thoughts?
New compressor is motor smoking?
I just bought a brand new 220 volt 60 gallon air compressor turn it on and runs for approx.10 seconds then motor starts to smoke. Should i return the compressor?
Paul, do you shut it off immediately after it starts to smoke, or have you let it run a bit? Have you checked the power supply? An incorrect power supply could quickly cause a hot compressor motor. Since I can’t see the amount of smoke, I can’t be sure that it’s not just a by-product of a new motor start up, or if the smoke is a symptom of a serious problem.
If you have turned the air compressor on a few times, and it’s run for a while (what does the manual say about the break in?) then I guess I’d be inclined to return it. Where there is smoke, there is something burning, and that’s not good if it persists.
Comment in response by: STICKS.
Sounds like wrong voltage to motor – check the voltage with a volt meter, check nameplate or data plate on motor for input voltage wiring, if it is a 3 phase motor make sure you have power between all three phases. The motor may be dual voltage, high/low voltage make sure the wiring matches incoming power to motor.
If you have any questions regarding your air compressor motor getting hot and sparking or smoking, please leave a comment below and a photo if applicable so that someone can help!
My Craftsman 5 Gal air compressor was sparking and tripping the GFCI at startup. I found the centrifugal switch and come loose on the motor spindle. I adjusted and tightened it and everything worked fine. The adjustment procedure can be found at a motor manufacturers website.
I have a Husky 30 gallon compressor C303H . It looks as though one of the brushes is bad. I’m getting sparking. Just wondering where I can get more brushes?
What’d HD or the Husky number say?
Hitachi EC510 – Video of sparking coming from the motor to see if it’s normal or the brushes starting to go.
The video is now live on the site, Barry. A viewer, when they click on the link, may have the video download, or it may open, depending on their computer settings. And yes, it sure looks like the brushes to me, though I suspect folks more learned will comment to. Cheers, and thanks for taking the time.
Not normal. Good brushes and commutator will spark, but nearly invisibly.
Might just be a weak pressure spring, but you’ll probably want to get a new set in any case.
You’ll probably find spark damage on the commutator, you want to get that off. Emory paper will work, usually.
Uh-oh. A quick check says the brushes were never available, and the motor set, as they call it, isn’t available either. I hope it’s just a bad/stuck brush spring…