Code
Description
Corrective Action
92
Condenser Fan 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 the sensor by substitution. Be sure the
range; or appears to be open or shorted.
sensor polarity is correct.
This alarm occurs only if the unit is using
the sensor to control condenser fan operation.
• Continuity check circuit wiring using a high quality
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.
97
Loss of Communications with Output Module
• Check the RXD and TXD LEDs at the top of the
(Shutdown Alarm)
output module. These LEDs should alternately flash
on a continuous basis to indicate a good
• Indicates a communications link between the
communications link.
controller and output module is not functioning.
• Check the cable from the controller to the thermo
bus tap. Check the cable from the thermo bus tap to
the output module. Check thermo bus tap for can
terminator resistor R4.
• Check controller using the Microprocessor Tester.
• Replace the Output Module.
4-66
Alarm Codes, Descriptions and Corrective Actions
µ
P-D Controller
CSR-20 & CSR-40, September 1999
