Carrier Performance 50VR-A Installation Instructions Manual page 36

SYMPTOM
Compressor and outdoor fan will not start
Compressor will not start but condenser fan
runs
Three- -phase scroll compressor (size 30- -60
unit) has a low pressure differential
Compressor cycles (other than normally
satisfying thermostat)
Compressor operates continuously
Excessive head pressure
Head pressure too low
Excessive suction pressure
Suction pressure too low
Table 12 – Troubleshooting Chart
CAUSE
Power failure
Fuse blown or circuit breaker tripped
Defective contactor, transformer or high--pressure,
loss--of--charge or low--pressure switch
Insufficient line voltage
Incorrect or faulty wiring
Thermostat setting too high
Faulty wiring or loose connections in compressor cir-
cuit
Compressor motor burned out, seized, or internal over-
load open
Defective run/start capacitor, overload, start relay
Scroll compressor is rotating in the wrong direction
Refrigerant overcharge or undercharge
Defective compressor
Insufficient line voltage
Blocked condenser
Defective run/start capacitor, overload or start relay
Defective thermostat
Faulty condenser--fan motor or capacitor
Restriction in refrigerant system
Dirty air filter
Unit undersized for load
Thermostat set too low
Low refrigerant charge
Mechanical damage in compressor
Air in system
Condenser coil dirty or restricted
Dirty air filter
Dirty indoor or outdoor coil
Refrigerant overcharged
Air in system
Low refrigerant charge
Compressor IPR leaking
Restriction in liquid tube
High heat load
Compressor IPR leaking
Refrigerant overcharged
Dirty air filter
Low refrigerant charge
Metering device or low side restricted
Insufficient evaporator airflow
Temperature too low in conditioned area
Outdoor ambient below 55F (12.7C)
Filter drier restricted
36
REMEDY
Call power company
Replace fuse or reset circuit breaker
Replace component
Determine cause and correct
Check wiring diagram and rewire correctly
Lower thermostat setting below room temperat-
ure
Check wiring and repair or replace
Determine cause
Replace compressor
Determine cause and replace
Correct the direction of rotation by reversing the
3--phase power leads to the unit
Recover refrigerant, evacuate system, and re-
charge to capacities shown on rating plate
Replace and determine cause
Determine cause and correct
Determine cause and correct
Determine cause and replace
Replace thermostat
Replace
Locate restriction and remove
Replace filter
Decrease load or increase unit size
Reset thermostat
Locate leak, repair, and recharge
Replace compressor
Recover refrigerant, evacuate system, and re-
charge
Clean coil or remove restriction
Replace filter
Clean coil
Recover excess refrigerant
Recover refrigerant, evacuate system, and re-
charge
Check for leaks, repair and recharge
Replace compressor
Remove restriction
Check for source and eliminate
Replace compressor
Recover excess refrigerant
Replace filter
Check for leaks, repair and recharge
Remove source of restriction
Increase air quantity
Check filter–replace if necessary
Reset thermostat
Install low--ambient kit
Replace filter