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aeb200
15-11-2005, 08:16 PM
Has anyone else experienced the loss of scroll compressor on city multi R22 units (about 3 years old) PURY250's
Ive had three go on different sites that I look after.

Compressors are completely DTE and inverter board cooked-

Could it be a problem caused by compressor & inverter running at low speed/frequency?

Could it be leaking linear expansion valves (LEV's)- as sites have had problems with water leaks over weekend (When fan is off LEV leaks freezing indoor coil then Monday morn they defrost overflowing drain pan)

Any thoughts?:(

Peter_1
15-11-2005, 10:59 PM
Had no similar experience but how long will it take now before the so praised VRV/VRF benefits will be re-earned (don't know the correct English expression)

Luckily you have 3 years warranty but if not...better install separate units without any PCB in it.

All that fancy electronics they try to push each day in our troat.

aeb200
15-11-2005, 11:15 PM
Mr Cooling Magic

When I said the LEV leaks refrigerant, I meant into the coil Not to Atmosphere
The gas charge on these units was correct

The LEV is like a TEV and the ones in qusetion have stuck slightly open -like a TEV jammed open, so they leak refreigerant into evaporator, if fan isn't running the coil will ice up

star882
16-11-2005, 05:00 AM
Has anyone else experienced the loss of scroll compressor on city multi R22 units (about 3 years old) PURY250's
Ive had three go on different sites that I look after.

Compressors are completely DTE and inverter board cooked-

Could it be a problem caused by compressor & inverter running at low speed/frequency?
Sounds like poor design to me. A similar design is used in a "supercomputer" built and operated by a few of my friends, and the inverter is designed such that if the compressor jams or shorts for any reason, the inverter will just switch off on overload.
Sounds like that at low speeds, it's running too slow so the bearings don't lubercate properly. And the inverter has no overload protection so it burns out once the compressor locks. Or maybe the inverter fails in such a manner that it puts DC onto the compressor and burns it out. (In the design used in the supercomputer, it will blow the B+ fuse.) Who knows, it could be just a firmware issue that started it all! (And I know the rule to never drive critical power electronics from a micro without a protection mechanism of some sort...)

ozairman
16-11-2005, 10:10 AM
Thats probably jumping to conclusions a bit isn't it? I would be waiting for the results of the autopsy of the compressors before pronouncing cause of death :-)