INSTALLATION GUIDE • USER MANUAL
1
5
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
1
System short of
capacity
Lower than expected suction
and discharge pressures
Low refrigerant charge
Check for leaks, repair, and
recharge. See item 5
Higher than expected
head pressure
Dirty condenser
Clean. See item 2
Lower than normal suction
pressure
Incorrect superheat -
too high
Adjust superheat
2
Head pressure
too high
Tripping high pressure switch, or
compressor trips on internal
overload
Dirty condenser
Clean condenser
Condenser air short
circuiting or location
too hot
Remove obstructions,
causes for air short circuiting
Defective condenser fan
motor or blade
Replace
Air or non-condensable
gases in the system
Purge the system
Refrigerant over charge
Remove excess refrigerant
3
Head pressure
too low
Sight glass with bubbles
Refrigerant leak or system
undercharged
Check for leaks, repair
and recharge
Plugged filter drier
Replace filter drier
Insufficient subcooling
Check condenser subcooling
circuit
4
Suction pressure
too high
Glycol temperature will not
reach set point
Excessive load on the
system
Check load and improve
conditions
Incorrect superheat
TEV stuck open due to
ice or defect
Check, repair, or re-
place TEV
Incorrect superheat setting
of the expansion valve
Adjust superheat
5
Suction pressure
too low
Sight glass with bubbles
See item 3
See item 3
Warm suction line, signs of
frost on the TEV and low
system capacity
Plugged TEV or strainer
Clean TEV and strainer
Compressor cycling due to
low pressure cutout
See item 12
See item 12
6
Noisy
compressor
Oil level below midpoint of the
compressor sight glass during
operation
Lack of oil
Avoid compressor short
cycling or run compressor
enough to return oil to
crankcase, correct low load
conditions. Add oil.
Noticeable knock in
compressor
Worn or scored bearings
Replace the compressor
Frosted suction line and
compressor shell
Liquid flood back
Check superheat and TEV
operation
GD-20H & GD-27H
MODELS
G&D CHILLERS, INC.
•
GD
-20-27H
-
M
S
_CRL-r2021A
