Troubleshooting; Cooling Service Analysis - Carrier 50TFF008-014 Installation, Start-Up And Service Instructions Manual

PROBLEM
Compressor and
condenser fans
will not start.
Compressor will not start
but condenser fans run.
Compressor cycles
(other than normally
satisfying thermostat).
Compressor operates
continuously.
Compressor makes exces-
sive noise (50TFF014
scroll only).
Excessive head pressure.
Head pressure too low.
Excessive suction
pressure.
Suction pressure too low.
Compressor no. 2
will not run.

TROUBLESHOOTING

Tables 21-23 are provided for troubleshooting the unit and economizer.
Table 21 — Cooling Service Analysis
CAUSE
Power failure.
Fuse blown or circuit breaker tripped.
Defective thermostat, contactor, transformer, or
control relay.
Insufficient line voltage.
Incorrect or faulty wiring.
Thermostat setting too high.
Faulty wiring or loose connections in compressor
circuit.
Compressor motor burned out, seized, or internal
overload open.
Defective run/start capacitor, overload, or start
relay.
One leg of 3-phase power dead.
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.
Leaking valves in compressor.
Air in system.
Condenser coil dirty or restricted.
Compressor rotating in wrong direction
Dirty air filter.
Dirty condenser coil.
Refrigerant overcharged.
Air in system.
Condenser air restricted or air short-cycling.
Outdoor fan contactor not energized.
Low refrigerant charge.
Compressor valves leaking.
Restriction in liquid tube.
High heat load.
Compressor valves leaking.
Refrigerant overcharged.
Dirty air filter.
Low refrigerant charge.
Metering device or low side restricted.
Insufficient evaporator airflow.
Temperature too low in conditioned area.
Field-installed filter drier restricted.
Unit in economizer mode.
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 temperature.
Check wiring and repair or replace.
Determine cause. Replace compressor.
Determine cause and replace.
Replace fuse or reset circuit breaker.
Determine cause.
Recover refrigerant, evacuate system, and recharge
to nameplate.
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 recharge.
Clean coil or remove restriction.
Reverse the 3-phase power leads as described in
Start-Up section, page 34.
Replace filter.
Clean coil.
Remove excess refrigerant.
Recover refrigerant, evacuate system, and recharge.
Determine cause and correct.
Verify outdoor fan coil receiving 24 vac and high voltage
contacts close.
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 and replace if
necessary.
Reset thermostat.
Replace.
Proper operation; no remedy necessary.
39
REMEDY