Thermo King CRR-20, Maintenance Manual

Page: 103 / 200

CRR-20 & CRR-40, September 1999
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P-D Controller Alarm Codes, Descriptions and Corrective Actions 4-49
Code Description Corrective Action
12 Temperature Out-of-Range High • Check for an open or defective door.
(Check Alarm)
• Check for proper setting of fresh air exchange.
• Indicates the control temperature has
exceeded the allowable temperature and • Perform a Full Pretrip Test to check unit operation.
time duration above the setpoint after
having been in-range.
13 Temperature Out-of-Range Low • Perform a Full Pretrip Test to check unit operation.
(Check Alarm) (Chill Loads ONLY)
• Indicates the control temperature has
exceeded the allowable temperature and
time duration below the setpoint after
having been in-range.
14 Defrost Terminated by TIme Limit • Check electric heater rod operation using the
(Check Alarm) “AMPS HEATR” test in the Electrical Test submenu.
• Indicates the controller terminated a defrost • Check for correct evaporator fan operation using
cycle due to time. the “REFRG DFRST” test in the Refrigeration Test
submenu.
• Check evaporator coil sensor for correct operation.
16 Digital Input Failure • Check for other alarms, particularly sensor alarm
(Shutdown Alarm) codes.
• Indicates one or more digital inputs (sensor, • Check controller using the Microprocessor Tester.
current transformer, pressure switch, etc.)
is erratic or has failed.
25 Return and Supply Sensor Failure • Check to be sure the sensor lead connector is
(Shutdown Alarm — setpoint at -9.9 C [14.1 F] securely attached to the controller and the sensor
or above) harness is securely attached to the control box.
(Check Alarm — setpoint at -10 C [14 F] or
below)
• Check for other sensor alarm codes, particularly
codes 03 and 07.
• Indicates both the return and supply sensors
have failed. • Continuity check the wiring to the temperature sen-
sors using a wiring diagram and digital multimeter.