Compressor Tripping MCB

[sellers]

An existing customer rang me today regarding their compressor tripping the breaker intermitantly.

I have never got involved with compressors before, but being an good customer I went down to see if it could be any other issue. The compressor is a single phase, plugged into a local socket on a 32A ring. The circuit isn't overloaded, also there is an RCD which doesn't trip, so we are looking at a Line Neutral issue. The compressor doesn't trip on start up so that rules out start up current.

A megger on the compressor turned up nothing. So off came the cover of the motor for a little inspection. I haven't experienced many motors, but from what I gather there were 2 capacitors in there, run and start. One of them had a burnt out terminal, so I've popped the spade on the other terminal (same side). I will be going back tomorrow to test the capacitor. Does anyone have any other ideas what to look for?

 

[SLIPSHOD & SLAPDASH]

Capacitors can hold quite a charge that hurts

 

[kerching]

Try EMR on Redmarsh or Denreys in town, either should have the bits on the shelf.................... :coat

 

[sellers]

I rang emr Kerch, used them a couple of times. Just a shame they don't do site visits to save me dismantling the motor from the compressor!

I'll start with testing the capacitors and go from there. I take it I can look for a decent resistance value on the windings too?

 

[Steve3948]

What is the running current, have you clamped amp meter on it while running, it could creep up as its running.

On a B Type Mcb it may just tip it over the edge.

 

[professional]

An existing customer rang me today regarding their compressor tripping the breaker intermitantly.I have never got involved with compressors before, but being an good customer I went down to see if it could be any other issue. The compressor is a single phase, plugged into a local socket on a 32A ring. The circuit isn't overloaded, also there is an RCD which doesn't trip, so we are looking at a Line Neutral issue. The compressor doesn't trip on start up so that rules out start up current.

A megger on the compressor turned up nothing. So off came the cover of the motor for a little inspection. I haven't experienced many motors, but from what I gather there were 2 capacitors in there, run and start. One of them had a burnt out terminal, so I've popped the spade on the other terminal (same side). I will be going back tomorrow to test the capacitor. Does anyone have any other ideas what to look for?

But the O/L protection on compressors is quite often of the "stick your finger in the air" variety - so I wouldn`t rule it out ....