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Thread: Display case frustration
07-26-2011, 07:31 PM #1
Display case frustration
This is an old upright display case. R22, semi herm with hot gas defrost. No discernible Model or serial. No crankcase pressure regulator. Box temp was high (50*). Superheat would fluctuate between 10 and 16*, suction between 59-62 psig. head pressure was 215psig (appx 107*) with about 8 degrees subcooling. Initially thought the hot gas solenoid may have been leaking through but I didn't see any temperature difference that would indicate that. At any rate, my suction was too high. I'm not sure what is causing this. Ambient in the store was 73*. Any insight would be much appreciated.
07-26-2011, 09:02 PM #2
What might cause high suction pressure with normal to slightly low head pressure???
I'd look at the compressor.
07-26-2011, 10:15 PM #3
Pump down test time...
07-26-2011, 10:27 PM #4Regular Guest
- Join Date
- Jan 2007
high super heater, high box temperature.
I think liquid volume is not enough. but the head pressure not high. maybe one piston of compressor had short circuit.
07-26-2011, 10:57 PM #5
Both pistons run off the same motor. You can have a broken rod, and still operate provided the rod broke very near to the crankshaft. If its a k-body, it doesn't have any kind of piston rings, so it will scrape the side of the cylinder and eventually loose capacity.
07-27-2011, 07:44 AM #6Professional Member
- Join Date
- Jun 2011
As the others said sounds like your compressor.
07-28-2011, 05:18 PM #7
Unfortunately I couldn't do a pump down. The only service valves were @ the compressor. It is a K-body. The comp is also making an odd repetitious clicking sound. I'm thinking I'm going to have to tell my service manager that the compressor is on it's way out. Just wanted to Make sure I wasn't missing anything. Thanks for the replies.