4-46 Alarm Codes, Descriptions and Corrective Actions µP-D Controller
CSR-20 & CSR-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.
• Sensor Check test detected an out-of-range
condition. • Continuity check circuit wiring using a high quality
multimeter. Be sure to maintain correct polarity or
• This sensor REQUIRES ice bath calibration or the sensor will not work.
correct sensor grade setup.
NOTE: Do NOT use a test light or other
NOTE: If the Supply Air sensor is the instrument; or controller damage may result.
controlling sensor when it fails, the
controller continues unit operation
using the Return Air sensor.