INSTALLATION GUIDE • USER MANUAL
1
7
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
11 Compressor starts
but cycles on
overload
Internal overload tripping
MUST WAIT 2-3 HOURS TO
CHECK IF IT WILL RESET
Loss of charge causing
insufficient motor cooling
Check for leaks, repair, and
recharge
Voltage is low or
unbalanced if 3-ph
1-ph fix undervoltage
protection, 3-ph correct
phase imbalance
Defective or wrong run
cap
Check and replace
Defective overload
Check current and re-
place compressor if
necessary
12 Compressor
runs but
cycles on…
…overload
See items 10 and 11
See items 10 and 11
…thermostat
Thermostat differential
set too close
Check and widen differential
…high pressure switch
See item 2
See item 2
---low pressure switch
See items 3 and 5
See items 3 and 5
Leaking liquid line solenoid
valve (LLSV)
Replace LLSV
Leaking compressor
valves
Replace compressor
Undercharged system
Check for leaks and
recharge
13
Internal
pressure
safety valve
(IPRV) opens
Refrigerant trapped in
compressor
Discharge service valve
closed
Open discharge service
valve
Discharge pressure exceeds high
pressure setting
High pressure switch
malfunction
Reset or replace high
pressure switch, see item 2
14 Will not start,
trips on
overload
Start relay damaged or
burned out
Too low or too high line
voltage
Correct and replace relay
Incorrect wiring
Replace relay and rewire per
compressor wiring diagram
Excessive cycling
See item 11
GD-20H & GD-27H
MODELS
G&D CHILLERS, INC.
•
GD
-20-27H
-
M
S
_CRL-r2021A