3 ph machine 'cutting out'

[Scrums]

After all my success at wiring up my brand new secondhand Viceroy pillar drill I find it stops when it feels like it. I say 'stops' rather than 'cuts out' because it does it when not under load and at different intervals - sometimes I'll get about 45secs out of it, sometimes about 8 or 9 minutes, then just as I start to think I'm imagining it - it stops!

Anyone any ideas?.....gotta be the on/off hasn't it? (which is the original, probably 15/20 + year old box) if this is the likely cause - easy enough to install a new one and anything specific I need to buy?

Chris.

 

[tjwoodms]

its more than likley the thermal overload cutting the power this happens when the motor draws to much current a few things to check

1 are all the connection points tight and in good order.
2 find somone with a clamp meter and measure how much current is drawn on each phase to the motor
3 on the bottom of the contactor you should see the thermal overload which usually will hace a small slider or dial to set the upper ampage limit make sure this is set the same as or slightly higher than motor rating in star (three legged cross)
4 remove the cover from the electrical box on the motor and have a good sniff if you detect a acrid type smell the chances are the motor requires a rewind or better still get the motor insulation tested (if you have an insulation tester give me a shout an i will talk you through it)