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Table 28 — Troubleshooting
SYMPTOMS CAUSE REMEDY
Cooler Circulating Pump Does
Not Run
Power line open Reset circuit breaker.
Control fuse or circuit breaker open Check control circuit for ground or short. Reset
breaker and replace fuse.
Compressor over temperature sensor open (06D) Find cause of high temperature and reset controls.
Tripped power breaker Check the controls. Find the cause of trip and reset
breaker.
Cooler circulating pump not running Power off — restart.
Pump binding — free pump.
Incorrect wiring —rewire.
Pump motor burned out — replace.
Loose terminal connection Check connections.
Improperly wired controls Check wiring and rewire if necessary.
Low line voltage Check line voltage — determine location of
voltage drop and remedy deficiency.
Compressor motor defective Check motor winding for open or short.
Replace compressor if necessary.
Seized compressor Replace compressor.
Compressor Cycles
Off on Loss of Charge
Loss of charge control erratic in action Repair leak and recharge.
Replace control.
Low refrigerant charge Add refrigerant.
Low suction temperature Raise cooler leaving fluid temperature set point.
Compressor Cycles Off on Out
of Range Condition
Thermistor failure Replace thermistor.
System load was reduced faster than controller
could remove stages
Unit will restart after fluid temperature rises back into
the control band. Avoid rapidly removing system
load.
Temperature controller deadband setting is too low Raise deadband setting.
Compressor Shuts Down on
High-Pressure Control
High-pressure control acting erratically Replace control.
Compressor discharge valve partially closed Open valve or replace (if defective).
Noncondensables in system Purge system.
Condenser scaled/dirty Clean condenser.
Condenser water pump or fans not operating Start pump — repair or replace if defective.
System overcharged with refrigerant Reduce charge.
Unit Operates Too Long
or Continuously
Low refrigerant charge Add refrigerant.
Control contacts fused Replace control.
Air in system Purge system.
Partially plugged or plugged expansion valve or filter
drier
Clean or replace as needed.
Defective insulation Replace or repair as needed.
Service load Keep doors and windows closed.
Inefficient compressor Check valves, and replace if necessary.
Unusual or Loud System
Noises
Piping vibration Support piping as required.
Check for loose pipe connections
Expansion valve hissing Add refrigerant.
Check for plugged liquid line filter drier.
Compressor noisy Replace compressor (worn bearings).
Check for loose compressor holddown bolts.
Compressor Loses Oil
Leak in system Repair leak.
Mechanical damage (Failed seals or broken scrolls) Replace compressor.
Oil trapped in line Check piping for oil traps.
Hot Liquid Line
Shortage of refrigerant due to leak Repair leak and recharge.
Frosted Liquid Line
Shutoff valve partially closed or restricted Open valve or remove restriction.
Restricted filter drier Replace filter drier.
Frosted Suction Line
Expansion valve admitting excess refrigerant (note:
this is a normal condition for brine applications)
Adjust expansion valve. Replace valve if defective.
Freeze-Up
Improper charging Make sure a full quantity of fluid is flowing through
the cooler while charging, and suction pressure in
cooler is equal to or greater than pressure corre-
sponding to 32 F (0° C) (58 psig [400 kPa] for
Refrigerant 22).
System not drained for winter shutdown
Recommended that system be filled with an appro-
priate glycol mixture to prevent freezing of pumps
and fluid tubing.
Loose Thermistor Verify thermistors are fully inserted in wells.