3-2
T-288
Table 3-1. Troubleshooting procedures - Continued
INDICATION/
TROUBLE
POSSIBLE CAUSES
REFERENCE
SECTION
3.4
ABNORMAL NOISES OR VIBRATIONS
Compressor
Loose mounting hardware
Worn bearings
Worn or broken valves
Liquid slugging
Insufficient oil
Clutch loose, rubbing or is defective
V-belt cracked, worn or loose
Check/Tighten
See Note.
See Note.
3.7
4.18.2
Check
Check/Adjust
Condenser or evaporator fans
Loose mounting hardware
Defective bearings
Blade interference
Blade missing or broken
Check/Tighten
Replace
Check
Check/Replace
3.5
ELECTRONIC THERMOSTAT MALFUNCTION
Will not control
Thermostat defective
Sensor defective
Defective wiring
Replace
Replace
Check
3.6
NO EVAPORATOR AIR FLOW OR RESTRICTED AIR FLOW
Air flow through coil blocked
Coil frosted over
Dirty coil
Dirty filter
Defrost coil
Clean
Clean/Replace
No or partial evaporator air flow
Motor running in reverse (wiring polarity incorrect)
Motor(s) defective
Motor brushes defective
Evaporator fan loose or defective
Return air filter dirty
Icing of coil/dirty coil
Fan relays EFR1 OR EFR2 defective
Safety device open
Check/5.1
4.16
4.16
4.16
Clean/Replace
Defrost/Clean
1.5
1.4
3.7
EXPANSION VALVE MALFUNCTION
Low suction pressure with high
superheat
Low refrigerant charge
Wax, oil or dirt plugging valve orifice
Ice formation at valve seat
Superheat setting too high
Power assembly failure
Loss of bulb charge
Broken capillary
4.9
Check
4.7
4.12
Replace
Replace
4.12
Low superheat and liquid slugging
in the compressor
Superheat setting too low
Ice or other foreign material holding valve open
Loose bulb
4.12
4.12
Check
Fluctuating suction pressure
Improper bulb location or loose bulb installation
Low superheat setting
4.12
4.12
3.8
NO OR INSUFFICIENT HEATING
Insufficient heating
Dirty or plugged heater coil or filter
Coolant valve malfunction or plugged
Low coolant level
Clean
Check
Check
No Heating
Coolant valve malfunction or plugged
Thermostat malfunction
Boost relay or pump malfunction
Safety device open
Check/Replace
3.5
Repair/Replace
1.4
Summary of Contents for Carrier TRANSICOLD 68RM35-604-20
Page 1: ...T 288 Rearmount 68RM35 604 20 R 134a NYCDOT...
Page 20: ...2 3 T 288 Figure 2 2 Automatic High Speed Cool Mode Operation with Reheat TDR 10 SEC...
Page 21: ...2 4 T 288 Figure 2 3 Automatic High Speed Cool Mode Operation No Reheat TDR 10 SEC...
Page 22: ...2 5 T 288 Figure 2 4 Automatic High Speed Heat Mode Operation Below 45_F Ambient TDR 10 SEC...
Page 43: ...5 3 T 288 Figure 5 2 Electrical Schematic Diagam Based on Drawing 68RM35 1038 12 TDR 10 SEC...
