19
Table 6—
Troubleshooting Chart
SYMPTOM
CAUSE
REMEDY
Compressor and outdoor fan
will not start
Power failure
Call power company
Fuse blown or circuit breaker tripped
Replace fuse or reset circuit breaker
Defective contactor, transformer, control relay, or high--
pressure, loss--of--charge or low--pressure switch
Replace component
Insufficient line voltage
Determine cause and correct
Incorrect or faulty wiring
Check wiring diagram and rewire correctly
User Interface setting too low/too high
Reset UI setting
Compressor will not start but condenser fan
runs
Faulty wiring or circuit
Loose connections in compressor
Check wiring and repair or replace
Compressor motor burned out, seized, or
Determine cause
internal overload open
Replace compressor
Defective run capacitor, overload, or PTC (positive
temperature coefficient) thermistor
Determine cause and replace
One leg of 3--phase power dead
Replace fuse or reset circuit breaker
Determine cause
Low input voltage (20 percent low)
Determine cause and correct
Three--phase scroll compressor (size 030--
060 unit) has a low pressure differential
Scroll compressor is rotating in the wrong direction
Correct the direction of rotation by reversing the
3--phase power leads to the unit
Compressor cycles (other than normally sat-
isfying) cooling/heating calls
Refrigerant overcharge or undercharge
Recover refrigerant, evacuate system, and re-
charge to capacities shown on rating plate
Defective compressor
Replace and determine cause
Insufficient line voltage
Determine cause and correct
Blocked outdoor coil
Determine cause and correct
Defective run/start capacitor, overload or start relay
Determine cause and replace
Faulty outdoor 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
UI temperature set too low
Reset UI setting
Low refrigerant charge
Locate leak, repair, and recharge
Air in system
Recover refrigerant, evacuate system, and re-
charge
Outdoor coil dirty or restricted
Clean coil or remove restriction
Excessive head pressure
Dirty air filter
Replace filter
Dirty indoor or outdoor coil
Clean coil
Refrigerant overcharged
Recover excess refrigerant
Air in system
Recover refrigerant, evacuate system, and re-
charge
Indoor or outdoor air restricted or air short--cycling
Determine cause and correct
Head pressure too low
Low refrigerant charge
Check for leaks, repair and recharge
Restriction in liquid tube
Remove restriction
Excessive suction pressure
High heat load
Check for source and eliminate
Reversing valve hung up or leaking internally
Replace valve
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 coil airflow
Check filter–replace if necessary
Temperature too low in conditioned area
Reset UI setting
Outdoor ambient below 55
°
F
Install low--ambient kit
Filter drier restricted
Replace
PA
3P