Piston compressor motor needs service possible rewind etc?

[bry1975]

Chaps,

Been having trouble with the rather old (40-50years old at least) piston type compressor the motor doesn't seem to have any
life yet once the belt is slackened runs like a goodun! 

Advice please?

Bry

[David Jupp]

If single phase, maybe the capacitor(s) is dying - or centrifugal switch stuck/failing.

If 3 phase, there isn't much to fail.

I'm assuming that you haven't made any changes to the supply wiring recently - long cables and the resulting voltage drop can cause big problems starting.

I'm also assuming no mechanical problem with the compressor.

[hermetic]

Check the non return valve if fitted, it could be that air already in the tank is "loading" the compressor and slowing the motor.

[bry1975]

Thanks chaps,

The motor is single phase, just ran it today the motor will run with no belt connected I just have to flick the pulley and it will spin, and will drive the pistons once the belt has been refitted but struggles.

The motor will not run from standstill with the belt fitted hence guessing it's the motor knacked.

[John Rudd]

as Dave Jupp said earlier...

Sounds like the motor start capacitor is in need of replacement and will be much cheaper than buying a new motor or at worst a new compressor...

There should be a cylindrical looking device with two wires comig out of it connected to the motor connection box...

Have a look at it and see if there are any numbers stamped or printed on its casing..

Post them up and we'll advise on how to proceed..