Operating manual - ChillPAC and LP ChillPAC Mk 3
010823 en 2021.06
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Cause
Solution
Defect oil return/
oil recovery system
1.
Check the function and position of the oil float switch (see descrip-
tion 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.
In the period after start-up and at low-load operation, the oil recovery system will return more oil to the
compressor than during full load.
At part-load operation, the oil will settle easier because of less boiling in the evaporator.
Drop in oil temperature
Cause
Solution
Wet suction gas due to too high R717
charge
Reduce charge.
Wet suction gas due to unstable LP regula-
tion (LP ChillPAC only)
Adjust settings for LP regulator in UniSAB III until R717
level in evaporator is steady.
Wet suction gas due to fluctuating load
Check secondary system.
Wet suction gas due to quick changes in
compressor capacity
Adjust settings for load/unload compressor capacity in
UniSAB III.
Too much compressor cooling
Reduce water flow or temperature to compressor cooling.
See compressor manual for more information.
5.6.3
Testing of chillers
Chillers supplied by Johnson Controls Denmark have been function and performance tested, as far as
possible.
A performance test consists of simultaneous measurements of cooling capacity, power consumption
and condenser capacity.
It is not a simple task to measure performance. High quality measuring and logger equipment is required
to make reliable and accurate measurements. Contact a Johnson Controls representative if a perform-
ance test is needed.
