Carrier 48ES---A - Manual (Page 35)

35
Table 12 – Troubleshooting Chart
SYMPTOM 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 contactor, transformer, 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
Thermostat setting too high
Lower thermostat temperature setting below
room temperature
Compressor will not start but condenser fan
runs
Faulty wiring or loose connections in compressor cir-
cuit
Check wiring and repair or replace
Compressor motor burned out, seized, or Determine cause
internal overload open 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
Low input voltage Determine cause and correct
Three--phase scroll compressor
Scroll compressor is rotating in the wrong direction
Correct the direction of rotation by reversing the
makes excessive noise, and there may be a
low pressure differential.
3--phase power leads to the unit. Shut down unit
to allow pressures to equalize.
Compressor cycles (other than normally sat-
isfying thermostat)
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 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
Thermostat temperature set too low Reset thermostat
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 condenser coil Clean coil
Refrigerant overcharged Recover excess refrigerant
Air in system
Recover refrigerant, evacuate system, and re-
charge
Condenser 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 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–replace if necessary
Temperature too low in conditioned area Reset thermostat
Outdoor ambient below 55°F (13°C) Install low--ambient kit
Filter drier restricted Replace filter
48E
S
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A