EWWQ090G ÷ EWWQ720L - R410A - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410A - Condenser less
EWHQ100G ÷ EWHQ400G - R410A - Heat pump scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWAQ-
- R410A - Air-cooled scroll chillers
EWYQ-
- R410A - Air-cooled scroll heat pumps
Air and Water cooled scroll chillers & heat pump
Operation
Manual
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
Operation Manual
67
Unit status is Off.
All circuits are stopped with a normal
shutdown procedure.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+UnitAlHRLwtSen
String in the alarm log:
UnitAlHRLwtSen
String in the alarm snapshot:
UnitAlHRLwtSen
Sensor is broken.
Check for sensor integrity.
Check correct sensors operation
according with information about
kOhm (k
) range related to
temperature values.
Sensor is shorted.
Check if sensor is shorted with a
resistance measurement.
Sensor is not properly connected
(open).
Check for absence of water or
humidity on electrical contacts.
Check for correct plug-in of the
electrical connectors on the UC.
Check for correct sensors wiring
according with wiring diagram.
6.1.2 Unit Pumpdown Stop Alarms
The following alarms will stop the unit commanding a pumpdown on all running circuits. The unit
will not run again until the root-cause of the alarm is not fixed.
6.1.2.1 Evaporator Entering Water Temperature (EEWT) sensor fault
This alarm is generated any time the input resistance is out of an acceptable range.
Symptom
Cause
Solution
Unit status is Off.
All circuits are stopped with a normal
shutdown procedure.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+UnitOff EvpEntWTempSen
String in the alarm log:
UnitOff EvpEntWTempSen
String in the alarm snapshot:
UnitOff EvapEntWTemp Sen
Sensor is broken.
Check for sensor integrity.
Check correct sensors operation
according with information about
kOhm (k
) range related to
temperature values.
Sensor is shorted.
Check if sensor is shorted with a
resistance measurement.
Sensor is not properly connected
(open).
Check for absence of water or
humidity on electrical contacts.
Check for correct plug-in of the
electrical connectors on the UC.
Check for correct sensors wiring
according with wiring diagram.
6.1.2.2 Evaporator Leaving Water Temperature (ELWT) sensor fault
This alarm is generated any time the input resistance is out of an acceptable range.
Symptom
Cause
Solution
Unit status is Off.
All circuits are stopped with a normal
shutdown procedure.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+UnitOff EvpLvgWTempSen
String in the alarm log:
UnitOff EvpLvgWTempSen
String in the alarm snapshot:
UnitOff EvapLvgWTemp Sen
Sensor is broken.
Check for sensor integrity.
Check correct sensors operation
according information about kOhm
(k
) range related to temperature
values.
Sensor is shorted.
Check if sensor is shorted with a
resistance measurement.
Sensor is not properly connected
(open).
Check for absence of water or
humidity on electrical contacts.
Check for correct plug-in of the
electrical connectors.
Check for correct sensors wiring
according with wiring diagram.
