Repedatley compressor burning problem
Repedatley compressor burning problem
(OP)
hi all!
we are facing a huge problem. We have mc quary make water based chiller system for cooling our control room and other halls. the problem is that we have refubrished the whole system. Only condersnors ( forced air - cooled) and frame left original. All other we install by our own. We have installed six copeland 7.5hp sealed screw compressors (original design was also of six compressors). and we installed all other accessories necessary and we got our system installed with some people having great expreince in chiller systems and they professionally do this business. But after 15 days of extremely successfull operation (when it goes on the temperature inside falls from 30 deg C to 7 deg C), suddenly compressors started burning. and we started to replace burned compressors with some refubrished (piston type compressors due to limitation of budget). We also hired some other professionals and they also tried but the problem is persistent.
Both are unable to give us any solid reason or able to fix the problem. Compressors are continously still getting their winding short (even refubrished piston).
We are using honeywell r-22 original usa made refigerant gas and silo compressor oil made for low temperatures.
Kindly help us.
Thanks in advance.
we are facing a huge problem. We have mc quary make water based chiller system for cooling our control room and other halls. the problem is that we have refubrished the whole system. Only condersnors ( forced air - cooled) and frame left original. All other we install by our own. We have installed six copeland 7.5hp sealed screw compressors (original design was also of six compressors). and we installed all other accessories necessary and we got our system installed with some people having great expreince in chiller systems and they professionally do this business. But after 15 days of extremely successfull operation (when it goes on the temperature inside falls from 30 deg C to 7 deg C), suddenly compressors started burning. and we started to replace burned compressors with some refubrished (piston type compressors due to limitation of budget). We also hired some other professionals and they also tried but the problem is persistent.
Both are unable to give us any solid reason or able to fix the problem. Compressors are continously still getting their winding short (even refubrished piston).
We are using honeywell r-22 original usa made refigerant gas and silo compressor oil made for low temperatures.
Kindly help us.
Thanks in advance.





RE: Repedatley compressor burning problem
The acid attacks the motor winding insulation, forming even more acid and causing the windings to short.
If all you do is install another compressor into a system with all that acid, then that compressor will not live long.
RE: Repedatley compressor burning problem
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Repedatley compressor burning problem
we are not just adding compressors to the system. When a compressor's winding got burnt we just changed the take it out and purge the other remaining system with high pressure of nitrogen. So hard that all the refrigerant and compressor oil in the system gets out and after that as well, when we connect the whole system then still we leak some r-22 to get rid of any moisture remained. Then we start charging the system.
Also the compressor suction line has refrigerant dryer of denfoss (conating silica gel) to absorb any moisture or any other impurity.
Also we have low suction pressure and high discharge pressure safeties on compressors.
Please now continue and help.
Thanks
RE: Repedatley compressor burning problem
You need to pull a hard vacuum and keep it on for at least an hour preferably more, before you start your recharge. Dry nitrogen helps for leak detection. But it cannot get all of the moisture out of a system.
B.E.
The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor
RE: Repedatley compressor burning problem
If the moisture level is severe (if you've had a broken evaporator tube, for example) you may freeze pockets of water at low points during the first evacuation. Might need to apply some heat to the low points while vacuum pump is running to get all the water out, or evacuate and pressurize several times.
If you were just changing for an upgrade, and you've already blown it with nitrogen (don't do that again, please) it shouldn't be such a problem.
Pull a good vacuum (at least 400 microns) and leave it for a couple hours, as berkshire suggested. Install new dryers again.
Let us know how it turns out!
Good on ya,
Goober Dave
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RE: Repedatley compressor burning problem
I would say that you need to review your commissioning proceedure thoroughly.
RE: Repedatley compressor burning problem
RE: Repedatley compressor burning problem
Sounds like low voltage.