Carrier 30GX

[norlandengineer]

I have a critical Global chiller with one compressor going out on fault code 61 - low discharge superheat, usually during the night. Am also having the RCCB trip out for the oil heater on the same circuit - are these faults likely to be connected?

[PaulZ]

Hi norlandengineer
If the RCCB on the oil heater is tripping you will probably find that the oil level in the compressor is dropping below the heater. On some Carriers these heaters are 115V and have fuses that blow when this happens. Sounds like the system could be short of refrigerant or there is a problem with the TX valve.
Paul

[Dimitris]

Hi Norlandengineer,
The probable cause of the alarm low discharge superheat
is oil in the cooler. Most likely, the unit starts and stops too many times in a short period of time.

[willow]

The oil heaters on this machine are 415v. You need to check whether its the oil sep or oil line heater causing the trip if its the oil sep then this could be connected to the superheat problem.This is caused if this circuit switches off due to low load or chiller not enabled through the night the oil cools (20 litres in a single compressor circuit) and holds a large amount of 134a .Then when demand increases circuit starts and shows symptoms of S.O.G until the discharge re heats the oil. Although generaly this problem occures in winter.