I have several 30GT carrier chillers to maintain. Several of these chillers don’t have a low side suction pressure switch to stop the compressor on a loss of suction. They are instead equipped with a “Loss Of Charge” switch that is connected to the discharge. What I have found a problem with the TXV or solenoid valve will cause compressor burn out on these machines.
Connecting the switch to the low pressure side will cause the compressor to trip during the initial 10 sec pump down cycle. We have confirmed through the provided documentation that the switch is supposed to be connected the high side of the compressor.
I have not been able to locate a low pressure safety on any chiller of this series. I am planning on installing low pressure protection on these machines in the very near future.
I would like to know if any one has seen a single module solution to resolve this. The switch will have to be disabled during the initial start up of the compressor and not cycle the compressor on a actual low suction situation.