Clarke 3 phase compressor

[ajlelectronics]

Mine is a couple or three years old. It has been reluctant to start just recently, but today it refuses. Motor is free to turn but it just hums when turned on. Pressure is very low in the tank as a result!

My first assumption is starting capacitor, any other suggestions?

 

[RustyBus]

No Starter caps on 3 phase. More likely to be a phase burnt out?

 

[daleyd]

Unloader valve? If it’s trying to start against pressure it might not be man enough - the unloader valve drops the pressure until it’s got time to spin up, otherwise possibly motor u/s

 

[rtbcomp]

Empty the tank completely, leave the outlet valve open and see if it starts then.

Remove the belt and see if the motor starts with no load at all on it.

 

[ajlelectronics]

I unplugged the 3P plug and noticed that two pins were discoloured. Re-insertion seemed to do the trick, so looks like I should change the plug.

Many thanks everyone for your help.

 

[Fintray]

Might be worth checking the socket as likely that those 2 socket connectors haven't been gripping those 2 pins of the plug sufficiently causing a bit of overheating.

 

[brightspark]

change both

 

[dannyp]

as said burn pins change both. new plug and socket much cheeper than new motor or a fire, any electrical connection that has gone bad will go bad again at some point usaly sooner rather than later