not pumping down

[cadwaladr]

Looking at a cold store today customer said it not stopping when door switch activated the switch is a basic switch that could be used for lighting etc,this switch energizes the liquid line mag valve,checked no power at valve attached gauges suction pressure high 65psi closed receiver valve ,no difference closed suction valve no difference? Asked customer if temperature log shows any warm readings no all seems to be right the compressor is a maneurop mtz 64 back to the compressor again closed valves again all works fine? I suspect the compressor is faulty as the customer said it did not stop when entry switch was used yesterday,any ideas has this happened to anyone in the past

[Tycho]

defective discharge or suction valves on the compressor?
works one minute, doesn't work the next, sounds like something is wobbling around inside the compressor.

[cadwaladr]

That's my guess looks like order a replacement

[monkey spanners]

Is it a scroll? Not sure if these will run backwards.

Had Copeland scrolls where the trip on LP but the the LP resets as the compressor is spinning backwards and it keeps running that way, runs like it till goes out on klixon then runs ok when resets.

[chemi-cool]

Is it a scroll? Not sure if these will run backwards.

Had Copeland scrolls where the trip on LP but the the LP resets as the compressor is spinning backwards and it keeps running that way, runs like it till goes out on klixon then runs ok when resets.

John, MTZ is recip.

Most probably valves are broken inside the compressor.

[monkey spanners]

John, MTZ is recip.

Most probably valves are broken inside the compressor.

Thanks Chemi, Aha! Don't see many maneurops, they are one of the more expensive makes here.

[abp32]

i had 3 phase pots run backwards on a big trane unit unit because the phases were switched by sparkies , it was my first month on the tools by myself , i had no idea what was going on except the pots seemed to be spinning backwards , i was pulling my hair out for a good few hours and had to ring the boss to come and help me , the joys of being new to the job

[cadwaladr]

This compressor must be working ok now,as I have had no call from the customer.

[Rob White]

.

I think the Maneurops have a pressure relief valve inside
the comp to prevent over pressurization?

If this is the case it is possible it activated and now has
sorted itself out?

If it is now OK and if it is running, then leave it alone.
I might last a week, a month or another year. Whatever
it does if it is OK take all the credit.

Regards

Rob

.

[cadwaladr]

You could be right Rob,anyway if not broke why fix it.