Troubleshooting
       Compressors Three



This website receives hundreds of questions about troubleshooting air compressors. In an effort to make some sense of the many questions received and answered, I have tried to categorize some of the questions into similar postings on each page. This is page three of questions and answers. Read on, please.

At the bottom of this page is a link to the forum on which you can ask a question of your own about compressor troubleshooting.

First new question: 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?

My response: 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 VOLTAGE WITH A VOLT METER, CHECK NAMEPLATE OR DATAPLATE 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 WIRNG MATCHES INCOMING POWER TO MOTOR

Another question about a compressor burning smell from? I have a new IR SS-5 compressor with less then 15 hrs on it and I started getting a burning smell, specially in the air. It is in a 26 x 28 residential garage and wide open to air. I drained the oil and replaced but still the same, I drained the tank and the first little bit it almost seemed like oil, a black milky water and then came clear approximately about a 1/2 cup in total drained out. I left open for a day then closed up and filled with air and right away the smell came back, any ideas?

My response: Compressing air generates a lot of heat. Some of that heat comes off the motor as it's running against load, and more comes off the compressor head and line to the tank since smashing air molecules together generates a lot of friction, and that generates heat. When you say the burning smell is in the air, do you mean around the air compressor, or coming out of the air line?

I suspect your compressor comes equipped with a thermal overload switch, which should shut it off if the motor overheats beyond the norm. I assume it's under warranty? Though it may just be a new car smell type odor, as the compressor heats up, the paint may be off-gassing. If under warranty, and if the problem persists, get the vendor to diagnose it further.

It were my compressor, I'd open the tank drain valve part way to let the air bleed, and I'd let it run continuously for a while. If it is not a continuous run model, shut it off after 15 minutes and let it cool for at least that long. Keep us posted, using the forum linked below, OK?

Air compressor problem - It just stopped working? Hello.. I just picked up a Iron Man 5hp 2-stage compressor that the guy said just stopped working. It's 220v and it's on its own breaker. When I plug it in I can hear the contacts on the switch engage but nothing happens. I'm sure if I left it plugged in it would blow the breaker. Everything spins freely. Capacitors look a little rough, can I check to see if the motor is junk before buying new capacitors. Thanks

My response: If the pressure switch trips to on when power is applied to the compressor and power is flowing through the switch to the motor circuit, and then nothing happens, I suspect it is either a start capacitor or motor problem. See the page on this site about testing your capacitor first to see if that has failed. If not then I would suspect the motor has pooched and needs to be tested.

My Air Compressor Runs for a bit then starts to shake and turns off?I have a SMC Vertical Air compressor. The compressor will start to run for a bit then it starts to shake quite a bit then throws the breaker on the electric motor of the compressor it's self. Any information would be a great help

Response: G'day, Steve. So, it runs for a bit... hmmmm? How long is that? Are we talking a couple of seconds, or couple of minutes, or somewhere in between? When it's running for a bit, are you seeing a pressure increase in the tank?

What starts to shake... the whole compressor, the motor, can you identify the item that's causing the shaking? In order for more-than-usual vibration to occur, something has let go.

I don't know your exact compressor, partially because you don't indicate the model, and mostly because there are eighty seven gazillion makes and models and I'd sure like to meet the person that could remember them all.

If there are motor mounts, check these. If there are any elastomeric mounts where the whole compressor pump and motor assembly are attached to the mounting plate, check these. Compressors vibrate like stink, and it's usually a soft, elastomere that absorbs the oscillation so that your compressor doesn't dance across the room like Fred Astaire on drugs. If you don't know who he is, don't sweat it. It just shows how old I am. :-)

As to it's shutting off, I don't know at what pressure that occurs, so is it going of on normal cut out, or is the vibration, perhaps, causing the pressure switch to trip off prematurely?

Comment by Al: Seeing that it drops out the circuit breaker on the motor! You have an excess load or a faulty motor. As you said you had the tank pipe disconnected! - Regards, Al ( elec fitter/tools specialist)

Comment by Steve I have further diagnosed the compressor. It seems if I take the line that feeds the air compressor tank of the pump. With the pump line attached to the tank it never starts to build pressure and only runs for about 2 minutes then shakes quite a bit. I have need around quite a few compressors and ever see one shake like this one.

That's it for this troubleshooting compressors page.

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