mariano-arg
02-10-2009, 07:02 PM
Hi everybody. I am dealing with a chiller PAC 1128, SAB rotatune, VSD, NH3, with a cooling capacity of 510 KW.
It run for a few months until the compressor crashed. I was called to give advice. I am not a refrigeration expert, but work with them (contractors who installed the unit).
Basically the compressor suffered from liquid carryover, washing the oil from the rotors, show damage in all the length of the rotors.
Had to install new compressor, but before asked advice to the contractors. They say they found the protections disabled, the equipment was probably overloaded with NH3, and that is it. (Hard to explain to management).
However when starting back up with new compressor, they reset the alarms and loaded the NH3. They were unable to set suction reheat over 0.3 °C, because of the unit tripping off. Run like that for a day, at a fixed capacity, however it triped off again, and now it won't start because of discharge reheat tripping off (set at 10°C @ 30 secs).
They say this equipment is "exact load" meaning don't overload NH3 by an ounce or compressor is gone. I am starting to think the separator is too small, (discharge line very close to normal liquid level), design not robust, probably protections not adequate.
I would like your opinions since I am not an expert and have to deal with some experts, wich could be part of the problem if I was correct on my suspicions.
I just want not to destroy the new compressor. Not much worried about who is guilty for the old one. However I think the root cause was not eliminated. Any suggestions would be appreciated.
It run for a few months until the compressor crashed. I was called to give advice. I am not a refrigeration expert, but work with them (contractors who installed the unit).
Basically the compressor suffered from liquid carryover, washing the oil from the rotors, show damage in all the length of the rotors.
Had to install new compressor, but before asked advice to the contractors. They say they found the protections disabled, the equipment was probably overloaded with NH3, and that is it. (Hard to explain to management).
However when starting back up with new compressor, they reset the alarms and loaded the NH3. They were unable to set suction reheat over 0.3 °C, because of the unit tripping off. Run like that for a day, at a fixed capacity, however it triped off again, and now it won't start because of discharge reheat tripping off (set at 10°C @ 30 secs).
They say this equipment is "exact load" meaning don't overload NH3 by an ounce or compressor is gone. I am starting to think the separator is too small, (discharge line very close to normal liquid level), design not robust, probably protections not adequate.
I would like your opinions since I am not an expert and have to deal with some experts, wich could be part of the problem if I was correct on my suspicions.
I just want not to destroy the new compressor. Not much worried about who is guilty for the old one. However I think the root cause was not eliminated. Any suggestions would be appreciated.