User`s manual

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38
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TROUBLESHOOTING
Table 19 — Cooling Service Analysis
PROBLEM CAUSE REMEDY
Compressor and
condenser fan will not
start.
Power failure. Call power company.
Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker.
Defective thermostat, contactor, transformer
or control relay.
Replace component.
Insufficient line voltage. Determine cause and correct.
Incorrect or faulty wiring. Check wiring diagram and rewire correctly.
Thermostat setting too high. Lower thermostat setting below room
temperature.
Compressor will not start
but condenser fan runs.
Faulty wiring or loose connections in
compressor circuit.
Check wiring and repair or replace.
Compressor motor burned out, seized,
or internal overload open.
Determine cause. Replace compressor.
Defective run/start capacitor, overload,
start relay.
Determine cause and replace.
One leg of 3-phase power dead. Replace fuse or reset circuit breaker.
Determine cause.
Compressor cycles
(other than normally
satisfying thermostat).
Refrigerant overcharge or undercharge. Recover refrigerant, evacuate system, and
recharge to nameplate specifications.
Defective compressor. Replace and determine cause.
Insufficient line voltage. Determine cause and correct.
Blocked condenser. Determine cause and correct.
Defective run/start capacitor, overload, or
start relay.
Determine cause and replace.
Defective thermostat. Replace thermostat.
Faulty condenser-fan motor or capacitor. Replace.
Restriction in refrigerant system. Locate restriction and remove.
Compressor makes
excessive noise
(580D150 scroll only).
Compressor rotating in wrong direction. Reverse the 3-phase power leads as described
on page 24.
Compressor operates
continuously.
Dirty air filter. Replace filter.
Unit undersized for load. Decrease load or increase unit size.
Thermostat set too low. Reset thermostat.
Low refrigerant charge. Locate leak; repair and recharge.
Leaking valves in compressor. Replace compressor.
Air in system. Recover refrigerant, evacuate system, and
recharge.
Condenser coil dirty or restricted. Clean coil or remove restriction.
Excessive head pressure.
Dirty air filter. Replace filter.
Dirty condenser coil. Clean coil.
Refrigerant overcharged. Recover excess refrigerant.
Air in system. Recover refrigerant, evacuate system, and
recharge.
Condenser air restricted or air short-cycling. Determine cause and correct.
Head pressure too low.
Low refrigerant charge. Check for leaks; repair and recharge.
Compressor valves leaking. Replace compressor.
Restriction in liquid tube. Remove restriction.
Excessive suction
pressure.
High heat load. Check for source and eliminate.
Compressor valves leaking. Replace compressor.
Refrigerant overcharged. Recover excess refrigerant.
Suction pressure too low.
Dirty air filter. Replace filter.
Low refrigerant charge. Check for leaks; repair and recharge.
Metering device or low side restricted. Remove source of restriction.
Insufficient evaporator airflow. Increase air quantity. Check filter and replace if
necessary.
Temperature too low in conditioned area. Reset thermostat.
Field-installed filter drier restricted. Replace.
Compressor no. 2 will
not run.
Unit in economizer mode. Proper operation; no remedy necessary.
Evaporator fan
will not shut off.
Time off delay not finished. Wait for 30 second off delay.