Emglo Air Compressor Motor Troubles

[j.robinson389]

I recently picked this air compressor up on CL for $100. If your interested in the back story here is the thread:
http://www.garagejournal.com/forum/showthread.php?t=176380


My actual problem:

The seller said that he tried to run it several times and each time the motor would start and run for <30 seconds then shut off. Ended up blowing one of the start capacitors. The 2hp 230V Gould Century Motor has two start capacitors and one run capacitor. He had just replaced the start cap when I showed. He plugged it back in and it blew the other start cap.

I am not very familiar with electric motors, but I was thinking that the start circuit is not disengaging and leaving the start capacitors engaged too long. Could this be the case?

Also, is it a problem that the two start caps are 125V BC-324 each and the motor is wired for 240V. Maybe that is normal, I am new to this.

Any ideas on what might be happening here? The seller said he replaced the air compressor about a year ago with a bigger one and when it went out of commission all was working fine.

The compressor is not at my house right now because I don't have a 240V circuit wired up yet, but I can get additional info if needed.

 

[bsaint]

I would try running the motor disconnected from the pump.

 

[j.robinson389]

That's where I'm at now, I took the belts off and the pump seemed to spin easily by hand. I ordered new capacitors, and as soon as I get my 30 amp circuit ran, I will test out the motor by itself.

I know this is a totally different topic, but would you agree that a 30 amp 240V dedicated circuit should be sufficient for up to a 5hp compressor?

 

[CJKaz]

Recommend having it tested by motor repair shop. A series of tests are performed to check the winding insulation, shorts between coils & shorts to ground. Specialized test equipment, not in the normal arsenel of DIY tools (Megger, Hi Pot, surge tester...).