Compressor motor

[magnum311]

Hello guys,
I have a boxer 50ltr air receiver compressor, seven years old, purchased new from from Machinemart. A problem has arisen with the thermal cut-out switch, which keeps tripping after thirty seconds or so, well before the receiver is fully charged. Any ideas as to what may be causing this, and also how hot should the motor get. Its a 3hp unit, no smell of burning, just the casing is very warm to the touch having been run.

Your expert opinions and replies will be much appreciated.
All best regards,
Magnum 311

 

[rtbcomp]

If the motor's running at the correct speed and is only warm I'd try fitting a new cutout switch.

 

[dobbslc]

It could be a duff start capacitor, that will cause the motor to run hot quite quickly.
Could be a stuck centrifugal switch, as above the start windings won't switch off after start up and get hot quick.

 

[Bill Edwards]

Is it belt drive or direct drive?
If you could remove a belt and check that the compressor is free to spin and try the motor with no load that'd be good.

 

[magnum311]

Hi Guys,
Sorry for long time in replying to your suggestions to my problem. It turned out to be a defective thermal overload switch. Rtb comp, you da man. Thanks for the help chaps. All the best,
Magnum 311.

 

[rtbcomp]

Thanks for letting us know