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14
Table 1 – 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 three---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.
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 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.
Outdoor ambient below 25° F.
Install low---ambient kit.
Evaporator Fan Will Not Shut
Off.
Time off delay not finished.
Wait for 30---second off delay.
Compressor Makes Excessive
Noise.
Compressor rotating in wrong direction.
Reverse the 3---phase power leads.
Summary of Contents for 50LC 07
Page 9: ...9 COOLING CHARGING CHARTS C150169 Fig 9 Cooling Charging Charts 07 ...
Page 10: ...10 COOLING CHARGING CHARTS C150172 Fig 10 Cooling Charging Charts 08 ...
Page 11: ...11 COOLING CHARGING CHARTS C150170 Fig 11 Cooling Charging Charts 09 ...
Page 12: ...12 COOLING CHARGING CHARTS C150171 Fig 12 Cooling Charging Charts 12 ...
Page 27: ...27 C150181 Fig 34 50LC 07 Control Wiring Diagram ...
Page 28: ...28 C150225 Fig 35 50LC 07 RTU Open Control Wiring Diagram ...
Page 29: ...29 C14095 Fig 36 50LC 07 Power Wiring Diagram 208 230V 460V and 575V Units ...
Page 30: ...30 C14013 Fig 37 50LC 08 12 Control Wiring Diagram ...
Page 31: ...31 C14104 Fig 38 50LC 08 12 RTU Open Control Wiring Diagram ...
Page 32: ...32 C14105 Fig 39 50LC 08 12 Power Wiring Diagram 208 230V Units ...
Page 33: ...33 C150216 Fig 40 50LC 08 12 Power Wiring Diagram 460V 575V Units ...
Page 57: ...57 C13683 Fig 62 Typical EconoMi er X Wiring Diagram ...