Table 4-1. Troubleshooting (continued)
TEST OR INSPECTION
AIR CONDITIONER NOISY DURING OPERATION (continued)
Adjust expansion valve if superheat is not correct (paragraph 4-15).
Inspect quench valve and check superheat (paragraph 4-16).
Repair or replace damaged or defective quench valve.
Adjust quench valve if
superheat is not correct (paragraph 4-16).
AIR CONDITIONER STOPS DUE TO HIGH PRESSURE SWITCH TRIPPING
Check air conditioner operating pressures for excessive refrigerant in system (table 4-3).
Release excess refrigerant from system until the proper charge is attained
Check for restriction in condenser air flow.
Clean condenser coil and/or remove restriction.
AIR CONDITIONER OPERATES CONTINUOUSLY ON COOLING CYCLE.
Check for insufficient refrigerant in system (bubbles in sight glass).
Add refrigerant (paragraph 4-11).
If adding refrigerant to system does not clear up bubbles in sight glass, there may be air in
evacuate system (figure 4-4), and recharge the system with refrigerant
SIGHT GLASS APPEARS YELLOW INSTEAD OF GREEN
Yellow appearance of sight glass is caused by contamination in the refrigerant.