Sterlco GC Series Central Chiller - Manual (Page 46)

GC Series Central Chillers Chapter 6: Troubleshooting 46 of 79
Chapter 6: Troubleshooting
Problem Possible cause Solution
Unit does not run.
No power.
Check main disconnect, fuses, wiring,
and power lead to unit.
Wrong voltage supplied to unit.
Voltage must be within plus or minus
10% of nameplate rating.
Defective display. Replace.
Control circuit fuse blown.
Replace control circuit fuse.
Check transformer.
Check for a short circuit.
Defective control transformer. Replace.
Piping flow switch circuit open.
Add water or water/glycol solution as
required.
Pump runs; compressor does not .
Leaving fluid setpoint set higher
than temperature of liquid in
system.
Lower the leaving fluid temperature
below the leaving temperature you
desire.
Compressor internal overload or
fuses are open.
Allow time to cool and reset, then check
for high/low volt-age. It must be within
plus or minus 10% of the nameplate
rating.
Check for open fuses and loose
compressor electrical connections.
Compressor contactor holding coil
open.
Repair or replace
Defective compressor auxiliary
contact.
Repair or replace.
Broken wire in the compressor
control circuit.
Locate and repair.
Pump runs, compressor(s) cycle(s)
at short intervals.
Plugged evaporator strainer Clean
Hot gas not coming on
Check hot gas analog output value
through status screen. Contact Service
if output value remains at 0%
throughout compressor cycle.
Low water flow
Install bypass between to-and-from
process line
Water temperature is too high.
Water/glycol mixture inadequate
for process.
Make sure that the water/glycol mixture
protection is right for the process.
Improperly set leaving fluid
temperature, warning, or fault set
point
Adjust.
Refrigerant charge is low.
Call service to find and repair the leak,
then have refrigerant added.
Pump process pressure is too high. Restricted water flow.
Check for partially closed valves etc.
Make sure that all lines are properly
sized.
Unit runs continuously, but not
enough cooling power
.
Restricted condenser air flow.
Clean filters.
Clean condenser.
Unit low on refrigerant.
Check the refrigerant charge by viewing
sight glass on liquid line upstream of the
expansion valve.