Air compressor diagnosis

[timelinex]

I've got a 5-10 year-old 8 gal HF air compressor that I've mostly used for airing tires, and it's worked great. This week I needed to do something that had it running constantly for 15min+ and it just stopped. It flipped my GFCI switch.

When I reset the switch, it turns back on for 0.5 seconds and then flips the GFCI again. (not the general breaker but just GFCI). I've tried other GFCI outlets and it does the same thing. I haven't tried non-gfci outlets as there is obviously a problem and I don't want to break something else.

I thought it was possibly the capacitor as that is a common break. Well I just received the replacement and it didn't help at all.

I got a nice 30gal Craftsman while waiting for the capacitor, so it's not a big deal to not get this fixed. But I would like to if I can (if anything, just to learn!).

Does anyone know what it could be or what my next steps are in diagnosis?

 

[PCustoms]

Start checking the power cord and any wiring for damage

 

[Beerhippie]

Hook it up to a non-GFCI outlet and watch for where the smoke comes out?

Seriously, use a multimeter and check for shorts to ground, to the case (should be the same as ground) and shorts between the two live wires.

 

[MovingAlong]

15 minutes is a pretty long run time for a small compressor.. suspect motor got hot and the brushes are smeared across the armature.

If you're comfortable tearing it down, it's not hard to clean up. Pull the brushes and take a pic of what you see inside, it's usually pretty obvious.

 

[The Cobbler]

maybe the windings got hot, melted the insulation a wee bit & you have a bit of a short .
I would run it on a non gfi & see what it does .