Abnormal Pressure; Abnormal Noise; No Evaporator Air Flow Or Restricted Air Flow - Carrier VECTOR 6500 Operation & Service Manual

INDICATION/
TROUBLE

9.4.8 Abnormal Pressure

High discharge pressure
Low discharge pressure
Low suction pressure
High suction pressure
Suction and discharge
pressures tend to equalize
when unit is operating

9.4.9 Abnormal Noise

Compressor
Condenser or evaporator fan
Water pump belt

9.4.10 No Evaporator Air Flow Or Restricted Air Flow

Evaporator coil blocked
No or partial evaporator
air flow
62-11389
Possible Causes
Condenser coil dirty
Condenser fans rotating backwards
Condenser fan inoperative
Refrigerant overcharge or noncondensibles
Discharge service valve partially closed
Compressor valves(s) worn or broken
Low refrigerant charge
Suction modulation valve malfunction
Filter-drier partially plugged
Low refrigerant charge
Expansion valve malfunction
No evaporator air flow or restricted air flow
Excessive frost on evaporator coil
Evaporator fan rotating backwards
Suction modulation valve malfunction
Liquid or suction line service valve partially closed
Compressor valves(s) worn or broken
Compressor gasket(s) defective
Heater contactor stuck closed
Compressor valves defective
Compressor gasket(s) defective
Loose mounting bolts
Worn bearings
Worn or broken valves
Liquid slugging
Insufficient oil
Loose or striking shroud
Bearings defective
Bent shaft
Cracked or worn
Frost on coil
Dirty coil
Evaporator fan loose or defective
Evaporator fan rotating backwards
Evaporator air flow blocked
9−6
Action/Refer-
ence Section
8.8.2
Check Wiring
Check
8.6.2
Open
8.7.1
8.6.2
8.8.5
8.8.3
8.6.2
9.4.11
9.4.10
9.4.7
Check Wiring
8.8.5
Open
8.7.1
8.7.1
Check
8.7.1
8.7.1
Tighten
8.7.1
8.7.1
9.4.11
8.7.5
Check
8.9.6/8.9.7
8.9.6/8.9.7
Replace
8.8.9
8.8.1
8.9.6
8.9.6
Check