Compressor problem

[edl]

i have a 5h, 2 stage compressor

been working fine - a few years old

last start up cycle it got stuck...don't know how else to say it - on start up, the electric motor came on and fought to turn the crank, but nothing...then it tripped the fused

i reset the fuse, triggering the motor on, loud humming/whirring ... but nothing - shut it off

waited a day, replaced the breaker (45amp/2 pole) same thing

any thoughts on how to diagnose/next steps?

thanks

 

[ducatithunder]

Take the belt of and try to turn the motor. Motor should turn freely. Then try to start the motor with the belt off. Does it have a capacitor start? If so sounds like your capacitor failed or is failing. If not and the motor checks out then my guess is your compressor locked up. Try to turn the compressor by hand. It will be a little resistance but should turn. If not and you cant then your compressor is locked up.

 

[edl]

thanks ... will do that

if "locked up" ... what exactly does that mean and how do i fix it?

 

[ducatithunder]

Could be that the unloader valve failed on the compressor or the piston is stuck. Does it get used often or usually sit for long periods of time? If the unloader is stuck then the motor will struggle to start since its starting with max load on the compressor .... then it trips the breaker. If the compressor spins by hand then look at the unloader.

 

[edl]

ok

thx

(and welcome!)

 

[204carcrazy]

my guess is the check valve failed and air in tank is going back into the pump putting too much pressure on the pump overloading motor and tripping the breaker. With switch off drain air from tank , this takes load off pump . Turn on switch and compressor should start if it is a failed check valve . Jim

 

[CrashmanS]

Mine had the same issue. Had to change the compressor pump oil to something more suited to my cold temperature. My compressor is in an unheated garage, and would trip the motor overload breaker when it was as cold as it has been. I don't remember the weight of oil. Call your compressor support and they can recommend an oil for your temp/climate. After I changed the oil it never happened again. This was my issue, yours may not be. But it sure has been cold lately. So something else to consider.

Sent from my SM-N920P using Tapatalk

 

[EOC_Jason]

I would follow what others have said to try and diagnose the problem...

1. Turn off the power to the comp...
2. Drain the tank so there's no air (so no resistance)
3. See if you can turn the flywheel by hand, if that is good then at least you know your compressor isn't locked up.
4. Turn on power and see if motor will turn pump now that tank is empty.

If it does, do you hear the 'hisss' when it shuts off like usual? If so, your unloader valve is okay. If not, then it might be plugged up and cleaned or replaced.

If it doesn't turn the pump or cuts out before building up full pressure then one of the capacitors is probably bad. Unplug and remove the cover for the caps. If you have a meter to test them you can do that, also if they are bulging or leaking any then that is a dead giveaway.

If the check valve is bad, then usually the unloader will continue to leak air.

Also doesn't hurt to check the oil, make sure it's at the proper level and isn't like syrup in this cold weather. If you haven't changed it ever, might be a good time.

 

[vtwinjunkie]

Even if it is locked up those are easy to rebuild.

cheap also.