Operating manual - ComPAC
011769 en 2020.03
47/56
Operating instructions
5.6.2 Troubleshooting
Too high condensing pressure
Cause Solution
Insufficient water flow through the
condenser
Adjust water supply, or clean the condenser.
Fouling in the condenser
Clean the condenser.
Too high cooling water temperature
Check cooling tower system, or reduce compressor
capacity.
Air or non-condensable gases in the system
Remove air from the condenser.
A 1°K lower condensing temperature results in a 1% higher cooling performance and 3% lower
power consumption.
Too low evaporating temperature
Cause Solution
Fouling in the evaporator Clean the evaporator.
Oil in the evaporator Inspect the oil recovery system.
Insufficient R717 charge
Check liquid level in evaporator.
Charge more R717 to the plant.
Suction gas superheat should be approx. 0.5 to 3°K.
A 1°K higher evaporating temperature results in a 4% higher cooling performance.
Missing oil
During the first 50 hours of operation, the compressor will lose oil. A few litres of oil will accumu-
late at the bottom of the oil separator, condenser and evaporator and never return to the com-
pressor. It is therefore not unusual that the compressor needs to be recharged with oil.
If the oil continues to disappear from the compressor, the oil return and recovery system must be
checked.
Cause Solution
Defect oil return/
oil recovery system
1. Check the function and position of the oil float switch (see de-
scription of oil recovery pot). When the float is up, the switch
must be closed (ON) and vice versa.
2. Check that the piston in the oil recovery pot is able to move
smoothly.
3. Check all solenoid valves and filters.
4. Check timers in Unisab III.
See Unisab III settings list for timer settings.
5. Check if the oil separator is filled with oil. If so, adjust the
timers in Unisab III. Increase the solenoid valve “ON” time.