Air Compressor help.

[blacksheep]

Ok, so i have a craftsman 20 gallon air compressor, and it dosnt seem to be working right anymore, it dosnt fill up all the way, and it always blows a circuit, itll start filling up, then it will start going on and off on and off, then itll blow the circuit


Its not my house electrical because i borrowed a friends 22 gallon husky compressor and it worked fine


What could be the problem? motor ?

[halbritt]

The motor could be at fault, but my first instinct is that there may be something wrong with the pressure switch. This is the switch that tells the motor when to turn on and off. There are a couple of other things to check as well. You may have a leak, which you can test by letting some pressure build in the tank with everything closed up. If you turn off the compressor and the tank doesn't hold pressure, there is a leak. Use soapy water to find it. Alternatively, the pump itself may be going bad and seizing. Purge the tank and leave it open, then disconnect the belt and see if you can turn the pump by hand. It should spin with relatively little effort. If it's seizing, it could cause the motor to stall, which leads to very high currents and possibly a thrown breaker. However, I think, this is less likely the case. With an AC motor, starting currents can be relatively high. If the motor is cycling on and off very quickly, it may be heating up the breaker which will eventually cause it to trip.