CSR-20 & CSR-40, September 1999
µ
P-D Controller
Alarm Codes, Descriptions and Corrective Actions
4-47
Code
Description
Corrective Action
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.
NOTE: This valve is not used on CSR units.
05
Evaporator Coil 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. 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 the correct polarity
• Controller also generates alarm in a Pretrip
or the sensor will not work.
test if the Evaporator Coil Sensor does not
show a decrease in temperature with only
NOTE: Do NOT use a test light or other
the compressor running.
instrument; or controller damage may result.
• If alarm occurs during a Pretrip test, a
dash (-) precedes the alarm code.
• This sensor REQUIRES ice bath calibration or
correct sensor grade setup.
NOTE: If the Evaporator Coil Sensor fails,
the controller continues unit operation using
other sensors and internal timers.
