Carrier CAPRI-280 Operation And Service Manual page 26

Table 3-3. General System Troubleshooting Procedures - Continued
INDICATION/
TROUBLE
ABNORMAL NOISE OR VIBRATIONS --- Continued
Condenser or evaporator fans
CONTROL SYSTEM MALFUNCTION
Will not control
NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW
Air flow through coil blocked
No or partial evaporator air flow
EXPANSION VALVE MALFUNCTION
Low suction pressure with high
superheat
Low superheat and liquid slugging
in the compressor
Side to side temperature differ-
ence (Warm Coil)
HEATING MALFUNCTION
Insufficient heating
No Heating
Continuous Heating
T-283
POSSIBLE CAUSES
Loose mounting hardware
Defective bearings
Blade interference
Blade missing or broken
Sensor or transducer defective
Relay(s) defective
Microprocessor controller malfunction
Coil frosted over
Dirty coil
Dirty filter
Motor(s) defective
Motor brushes defective
Evaporator fan loose or defective
Fan damaged
Return air filter dirty
icing of coil
Fan relay(s) defective
Safety device open
Fan rotation incorrect
Low refrigerant charge
Wax, oil or dirt plugging valve orifice
Ice formation at valve seat
Power assembly failure
Loss of bulb charge
Broken capillary
Superheat setting too low
Ice or other foreign material holding valve open
Wax, oil or dirt plugging valve orifice
Ice formation at valve seat
Power assembly failure
Loss of bulb charge
Broken capillary
Dirty or plugged heater core
Coolant solenoid valve(s) malfunctioning or plugged
Low coolant level
Strainer(s) plugged
Hand valve(s) closed
Water pumps defective
Auxiliary Heater malfunctioning.
Coolant solenoid valve(s) malfunctioning or plugged
Controller malfunction
Pump(s) malfunctioning
Safety device open
Coolant solenoid valve stuck open
3-5
REFERENCE
SECTION
Check/Tighten
Replace
Check
Check/Replace
4.14 or 4.15
Check
Check
Defrost coil
Clean
Clean/Replace
Repair/Replace
Replace
Repair/Replace
Repair/Replace
Clean/Replace
Clean/Defrost
Check/Replace
1.6
Check
4.5 and 4.7
Check
4.6
Replace
Replace
4.11
4.11
4.6
Check
4.6
Replace
Replace
4.11
Clean
Check/Replace
Check
Clean
Open
Repair/Replace
Repair/Replace
Check/Replace
Replace
Repair/Replace
1.6
Replace