Faulty compressor?

[Kirky]

Hi all had a recent call out to a Airedale KKCS3 chiller. On arrive found mcb had tripped. Found compressor common winding had burnt flag terminal and wire. Checked out usual stuff on compressor no earth faults resistances ok and continuity across winding ok. Replaced damaged terminal wire and reconnected. Checked for continuity between comp terminals and contactor terminals got good connection. Reset and ran unit compressor starts but stops after few seconds tripping fault relay. Compressor not overly hot but suppose doesn't run for long enough. The compressor is 3 phs so no capacitors or start relays to worry about. I have checked for voltage imbalance which is ok. I reset and ran unit again taking amp readings wasn't high before tripping. I'm thinking bad comp but just a little doubt in my mind because all checks seemed ok and comp isn't overheating. What you think am I missing something. Oh system charge ok not short

[chemi-cool]

disconnect the earth and let it run for a while, see if it runs ok, it could be the fan motor.

[Kirky]

The fan motors are ok the comp ran long enough to start them. So I've seen them run. What has happened though is the unit is now running not cycled off yet so watching it make sure it cycles back on. Not exactly sure why its ran this time I checked all my connections early today they are good. Compressor must of been jammed. I gave it a smack and it ran maybe coincidence dunno time will tell. I will let you know

[Kirky]

Unit has cycled on and off a few times now no excessive amp draw on start up everything looks ok ? What do you think happened there. Was the compressor jammed and I loosened it with a smack. If so why wasn't it red hot and why didn't it pull high amps. ?????

[chemi-cool]

I dont like compressors cycling, it indicates a pressure problem some where, pressure problems leads to oil return problems and oil return problems leads to seized compressors.

Have a good check up of the system to find where your problem comes from.

[WeNeedUnions]

The initial problem not sure of the second though was probably caused from water getting into the compressor terminal block from when its raining water runs is from the condenser fan opening or even droplets over water from your suction line when the chiller is in operation and thats normally what you see as a result is a scorched wire termination and breaker tripped from the arc/short across the phases I have personally had to seal 30 plus comp terminal blocks as they are not weather proof nor water proof and are exposed to the elements.

[Magoo]

Possibly the internal klixon was damaged when initial fault occured. New compressor.

[Mick13]

u said it was burnt on the common winding terminal?
am i missing something or do only single phase motors have a common winding?

[pandoras]

You have to replace your faulty compressor as soon as possible.For More information please visit www(dot)pandorasoem(dot)com.

[Kirky]

Customer will not replace compressor as its costly and the unit is still running without problem. They will ring me next time it fails.

[Amma]

Compressors are actually very dependable so typically,when your A/C compressor has gone bad there is an underlying cause that needs to be addressed lest the problem reemerge even after the unit has been replaced.Along with being the most important piece of your A/C system,the compressor is also the most expensive to replace.