Carrier 69NT40-489-100 Series - Troubleshooting; Unit will Not Start or Starts then Stops; Unit Operates Long or Continuously in Cooling

53
T-305
SECTION 5
TROUBLESHOOTING
NOTE
This troubleshooting chart is to be used for refrigeration troubleshooting only,
for Controlled Atmosphere troubleshooting refer to Section 11, page 115.
CONDITION
POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.1 UNIT WILL NOT START OR STARTS THEN STOPS
No power to unit
External power source OFF Turn on
Start-Stop switch OFF or defective Check
Circuit breaker tripped or OFF Check
Autotransformer not connected 4.2.2, page 45
Loss of control power
Circuit breaker OFF or defective Check
Control transformer defective Replace
Fuse (F3) blown Check
Start-Stop switch OFF or defective Check
Component(s) Not Operating
Evaporator fan motor internal protector open 6.16, page 70
Condenser fan motor internal protector open 6.11, page 66
Compressor internal protector open 6.8, page 61
High pressure switch open 5.7, page 55
Heat termination thermostat open Replace
Compressor hums, but does not
start
Low line voltage Check
Single phasing Check
Shorted or grounded motor windings 6.8, page 61
Compressor seized 6.8, page 61
5.2 UNIT OPERATES LONG OR CONTINUOUSLY IN COOLING
Container
Hot load (Failure to Pre--Cool) Normal
Defective box insulation or air leak Repair
Refrigeration System
Unit in Emergency Bypass mode. 4.11.1, page 52
Shortage of refrigerant 6.7.1, page 60
Evaporator coil covered with ice 5.6, page 54
Evaporator coil plugged with debris 6.15, page 70
Evaporator fan(s) rotating backwards
6.15, page 70
6.16, page 70
Defective evaporator fan motor/capacitor 6.17, page 71
Air bypass around evaporator coil Check
Controller set too low Reset
Compressor service valves or liquid line shutoff valve par-
tially closed
Open valves
completely
Dirty condenser 6.10, page 66
Compressor worn 6.8, page 61
Current limit (function code Cd32) set to wrong value 3.3.5, page 20
Suction modulation valve malfunction 6.18, page 71