HP (Hewlett-Packard) A0554832 Refrigerator User Manual


 
2-40 HP Portable Chillers Chapter 6: Troubleshooting 41 of 78
Chapter 6: Troubleshooting
Problem Possible cause Solution
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 on/off switch. Replace.
Replace control circuit fuse.
Check transformer.
Control circuit fuse blown.
Check for a short circuit.
Defective control transformer. Replace.
Piping flow switch circuit open.
Add water or water/glycol solution as
required.
Unit does not run.
Pump motor off on overload. Reset and test.
High/Low thermostat set higher
than temperature of liquid in
system.
Lower thermostat stage 1 set to 10°F
(6°C) below the leaving temperature
you want.
Defective High/Low thermostat. Replace.
Low refrigerant indicator on. Check refrigerant charge.
Refrigerant low pressure switch
contacts open.
Sight glass should be clear and the
moisture indicator should be green
while compressor is running. Bubbles or
foaming is normal when the hot-gas by-
pass solenoid is energized. Call for
service if bubbling is occurring and/or
moisture indicator is yellow.
Clean the air filters.
Check condenser fans for proper
rotation.
Check for dirty condenser.
Refrigerant high-pressure indicator
on.
Reset and test.
Fan motor out on overload. Reset and test.
Defective fan cycling control. Replace.
Defective fan motor. Repair or replace.
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.
Compressor internal overload or
fuses are open.
Check for open fuses and loose
compressor electrical connections.
Compressor contactor holding coil
open.
Repair or replace.
Defective pump motor to
compressor auxiliary contact.
Repair or replace.
Pump runs; compressor does not.
Broken wire in the compressor
control circuit.
Locate and repair.
Pump runs, compressor cycles at
short intervals.
Incorrect High/Low Thermostat
setting.
Lower set point to 10°F (6°C) below
desired leaving water temperature.