Compressor diagnostic

[wilko123]

Hello Fridge engineers!

I came across some tandem copeland compressors on a climaveneta chiller recently and whilst they were running noticed that various cylinder heads were very cold too touch. Othere were hot as suspected.

Is this a cause of valve failure letting by?

anyone offer some recommendaitons?

[Crash Pilot]

wilko123

Don't know the system you are talking about however I don't beleave it would be the valves. During the compression stroke you are superheating the discharge gas and with heat of compression the head should always be warm so I would say the cold temperature of the head is due to thermal migration through the compressor casing from the low side. Either caused by liquid flood back or liquid injection. Also if the valves are leaking this will cause a leak from the high side to the low increasing low pressure.

Need more info like pressures.

One way that I test the valves on dual compressor systems that have common suction and discharge line is to.

1. Electrically isolate the suspected faulty compressor and leave system off for a day or until both compressor are ambient temp.
2. Then start the good compressor while holding hand on suction pipe of suspected faulty compressor.
3. If the suction pipe temp starts to increase in temp then common suction line is drawing high side gas through valves of disconnected compressor.

Crash Pilot

[zwusel26]

The Controller have 2 steps 50 -100 %
or more if you have a 4 step controller 25-50-75-100 % you willfound unloaded cylinder .

[wilko123]

thanks for feedback chaps...

[joe magee]

One's Suction "cold" One's Discharge. Next?