PDA

View Full Version : weird situation



low0tech
08-05-2010, 05:03 PM
Hallo everybody, yesterday i went to see a carrier chiller with reciprocating compressor. The thermomagnetic breaker was down and all the winding were grounded.
The water pipes were out of water and full of air, or R22 i can't tell for sure, my question is can the compressor get grounded if it was working without water?And can the flow switch (mechanical) be tricked if the water pump is huge and close the circuit although the major lack of water????:confused:

Grizzly
08-05-2010, 07:52 PM
Hi low0tech.
Simply put ,you can set the flow pressure required to operate on most flow switches.
So the switch could be set so "Light", that a poor or reduced flow could still satisfy the switch.
Resulting in the pump continuing to run.
However it is more normal to find a sticking or seized flow switch.
I have even encountered ones where the paddle length has been to long, resulting in the switch being locked on. Due to the paddle grounding on the opposite side of the pipe.
A pump running with low water levels in the pipework will indeed result in air in the system.
Why would you consider R22. Surely checking with a leak detector will confirm what the gas is.
Having said all of the above. I would think the recip issues were a bigger problem.
If it is a semi hermetic comp which relies upon suction cooling through the windings then.
All the issues above could have started with cross contamination and refrigerant loss?
Maybe you could tell us more?
Cheers Grizzly

low0tech
29-05-2010, 02:03 PM
hallo Grizzly thanks for the reply and let me tell you what i saw the second time i visited that field...
the flow switch paddle was bended by hand like U to fit in the pipe hole but not well enough so it was sticking somewhere....I put a leak detector in the pipe and didn't bleep and also i found pressure in the compressor...(By cross contamination you mean mixed refrigerant with water???) So i can say for sure the cooler is not broken, now about the lack of refrigerant we haven't recovered the ref yet....Although i have to thank you for helping me put my mind in order....