Compressor humming for a few seconds, then tripping breaker - SOLVED!

[sqslabs]

Our compressor tripped the breaker a bit ago when kicking in and after resetting everything, upon startup the motor hums for a few seconds and then the breaker trips again.  Trying to figure out if its a breaker issue, or worse a compressor issue.  This is our main compressor so we're out of luck while its down. 

Full disclosure, its a Husky 5HP model that we probably should have replaced a long time ago.  I also have a Curtis 3HP compressor (same size tank as the Husky) in storage but was under the impression from some very brief research that it may be underpowered for the press.  I'd be happy to put that one into action if it will work, as its probably much more suited for the job.  Any help/thoughts would be greatly appreciated.

[ericheartsu]

someone much more qualified then me, and probably way smarter, will chime in, but i think your motor is dead.

[broadway]

It has happened to me and i replcaced the breaker and it worked.

[sqslabs]

someone much more qualified then me, and probably way smarter, will chime in, but i think your motor is dead.

I was worried someone was gonna say that.. 

It has happened to me and i replcaced the breaker and it worked.

We've had a breaker replaced one time before and it fixed the issues but at that time it was tripping either immediately on startup or during the cycle.  The difference this time is the humming and the motor not spinning at all from what I can tell.

[blue moon]

see if the compressor/pump will turn by hand. If it's seized the motor will try to turn it and trip when it fails to do so.

pierre

[jvanick]

it could also be a failed motor start capacitor.

-J

[sqslabs]

see if the compressor/pump will turn by hand. If it's seized the motor will try to turn it and trip when it fails to do so.

Tried turning the belt and everything seems to be operating fine in this department...

it could also be a failed motor start capacitor.

Definitely beyond my level of fix-it-ness, but will see what info I can dig up..

[LoneWolf2]

Had this exact thing happen to my Schulz 5hp compressor a couple months ago. Diagnosis was a fried motor. Luckily my local tractor supply had a replacement motor that dropped right in. So $230ish and a couple hours later we were back in business.

[Homer]

it could also be a failed motor start capacitor.

-J

agreed. we had this before. happened in our power washer as well. is the breaker hot?

[Ross_S]

Check the connections (Is one wire loose, not tight).  Are you running 3 phase power?  If so go check and make sure you have equal voltage on each leg.

[3Deep]

Your belt might be loose, and check for any arcing wires...I would change the breaker as that is the easiest and cheap way to go first....almost forgot check your point's they should be in a box on the compressor

[Binkspot]

Like Jason said start capacitor. Pull the cover and take the numbers off the old and replace. There might be run capacitors also and or two or more of each. Short the two terminals with a screw driver (hold the handle not the shank) before touching the wires.

[sqslabs]

Thanks to everyone for their feedback on this.  I've checked all the electrical connections and replaced the breaker, no improvement.  Gonna check out the capacitor now but otherwise it looks like it may be beyond my level of expertise so I'm gonna call in a tech to check it out.  My guys are killing it on the manual today so that will help and then we're closed through Monday so hopefully I'll get something up and running by then.

One of those days...

[ebscreen]

Two. Of. Everything.

[balloonguy]

are you in FL? We had the same thing yesterday. It turns out that one of the legs was blown at the pole. We had power for the lights, dryer... Everything seemed fine so I thought my compressor motor froze. I hooked the spare up and had the same problem. The FPL guys got it fixed in 3 minutes. They said anything with a big motor was effected. Everything else was fine.
Good Luck.