Carrier X4 7300 Operation & Service Manual page 271

Indication/Trouble
9.3.11 Abnormal Noise
Compressor
Condenser or evaporator fan
Alternator/Water pump belt
9.3.12 No Evaporator Air Flow Or Restricted Air Flow
Evaporator coil blocked
No or partial evaporator air flow
9.3.13 Expansion Valve (EVXV) Malfunction
EVXV not controlling correctly
9.3.14 Compressor Suction Modulation Valve (CSMV) Malfunction
CSMV not controlling correctly
9.3.15 Solenoid Valve Malfunction
Valve does not function properly
Valve closes but refrigerant con-
tinues to flow
Possible Causes
Loose mounting bolts
Worn bearings
Worn or broken valves
Liquid slugging
Insufficient oil
Condenser fan
Evaporator fan
Fan shaft
Alternator belt loose/broken
Frost on coil
Dirty coil
Upper belt loose or broken
Evaporator fan loose or defective
Evaporator air flow blocked
Low refrigerant charge
EVOT defective
Coil not seated properly on valve
EVOP defective
EVXV inlet screen plugged
Damaged or corroded electrical connections at valve or
SVM
Coil not seated properly
Coil defective
CSP defective
CST defective
Damaged or corroded electrical connections at valve or
SVM
No power to valve
Damaged or corroded electrical connections
Coil defective or improperly assembled
Valve improperly assembled
Foreign material in valve or valve worn
Foreign material in valve or valve worn
9–7
Action / Reference
Tighten
8.8.1
8.8.1
9.3.13
8.8.5
8.6.3
8.6.5
8.6.6
8.5.15
8.9.13
8.9.1
8.6.2
8.6.5
Check
8.7.2
8.10.7
8.9.12
Check
Check/Replace
Check/Repair
Check
8.9.8
8.9.12
8.10.7
Check/Repair
Check alarms
Check/Repair
8.9.5 / 8.9.6
8.9.5 / 8.9.6
8.9.5 / 8.9.6
8.9.5 / 8.9.6
62-11637