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Alarm Codes, Descriptions and Corrective Actions
µ
P-D Controller
CRR-20 & CRR-40, September 1999
Alarm Codes, Descriptions and Corrective Actions
Code
Description
Corrective Action
00
No Fault
• None Required
02
Ambient Temperature Sensor Failure
• Check the sensor by selecting it using the View
(Check Alarm)
menu. If the display shows [- - - -], the sensor is
defective or the circuit is open or shorted.
• Indicates a problem exists with this sensor
or its wiring. The sensor is reading out-of-
• Check sensor by substitution. Be sure sensor
range; or appears to be open or shorted.
polarity is correct.
• This sensor does NOT require ice bath
• Continuity check circuit wiring using a high quality
calibration.
multimeter. Be sure to maintain the correct polarity
or the sensor will not work.
NOTE: Do NOT use a test light or other instru-
ment; or controller damage may result.
03
Supply Air Temperature Sensor Failure
• Check the sensor by selecting it using the RET/SUP
(Check Alarm)
key (if necessary). If the display shows [- - - -], the
sensor is defective or the circuit is open or shorted.
• Indicates a problem exists with this sensor
or its wiring. The sensor is reading out-of-
• Check sensor by substitution. Be sure sensor
range; or appears to be open or shorted.
polarity is correct. Replacement sensor MUST be
calibrated or sensor grade set.
• This sensor REQUIRES ice bath calibration or
correct sensor grade setup.
• Continuity check circuit wiring using a high quality
multimeter. Be sure to maintain correct polarity or
NOTE: If the Supply Air sensor is the
the sensor will not work.
controlling sensor when it fails, the
controller continues unit operation
NOTE: Do NOT use a test light or other instru--
using the Return Air sensor.
ment; or controller damage may result.
04
KVQ Valve Thermistor Error
• Check the KVQ valve thermistor circuit with an
(Check Alarm)
ohmmeter. Good thermistor sensor should read
20,000 ohms at 20 C (78 F).
• Indicates a problem exists with the thermistor
or its wiring.
• Continuity check circuit wiring using a high quality
ohmmeter. Be sure to maintain the correct polarity.
• If the Thermistor fails, the KVQ valve
actuator must be replaced.
NOTE: Do NOT use a test light or other instru-
ment; or controller damage may result.
Summary of Contents for CRR-20
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