Aircon 3ph induction motor (1.5kw) destroyed by phase loss several times, as was a similar compressor motor.
Installed phase loss detectors controlling contactors - latest phase loss caused instantaneous catastrophic failure of the contactor supplying the aircon unit - supply MCBs to the aircon didn't trip but the old rewireables local to the motor did blow on the live phases.
Replaced the burnt bits and the aircon runs fine - why did this happen ??
Not being any sort of expert in power distribution I'm wondering if a recloser chattered the contactor or is this more to do with the motor.
I'm going to replace the simple phase loss detector with a timed unit with over/under voltage detection - am I going the right way ?
Chris
