Thermo King 098916, Maintenance Manual

Page: 162 / 196

Diagnosis: Troubleshooting, Status Messages, Alarm Codes
161
Low suction pressure
NOTE: This unit has a capacity
control system. Suction and
discharge pressures may drop below
expected normal readings when the
unit is on Modulation Cool (control
temperature within 10 C [18 F] of
setpoint or in Power Limit mode).
Shortage of refrigerant Repair leak and recharge
Low ambient air temperature No remedy
Iced or dirty evaporator coil Defrost or clean evaporator coil
Restricted lines Locate and clear restriction
Plugged filter drier Replace filter drier
Expansion valve closed too much Adjust or replace valve
Expansion valve feeler bulb
improperly mounted, poorly insulated
or making poor contact
Correct feeler bulb installation
Evaporator fans off
Check evaporator fan motors and
control circuit and correct fault
Defective controller or main relay
board
Diagnose main relay board and
controller. Replace defective
component
Service gauge out of calibration Adjust or replace gauge
Condition Possible Cause Remedy