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CRR-20 & CRR-40, September 1999
µ
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.
Содержание CRR-20
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