EWWQ090G ÷ EWWQ720L - R410A - Water-cooled scroll chillers
EWLQ090G ÷ EWLQ720L - R410A - Condenser less
EWHQ100G ÷ EWHQ400G - R410A - Heat pump scroll chillers
EWAQ-G 075
- 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
Operation Manual
66
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
6.1.1.2 Bad Lwt Reset Input Signal
This alarm can occurs only when the function Lwt Reset is enabled (see section 0). It indicates that
the Lwt Reset signal input is out of admissible range
Symptom
Cause
Solution
Unit status is Run.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+LwtResetAlm
String in the alarm log:
LwtResetAlm
String in the alarm snapshot:
LwtReset Alm
Lwt Reset input signal is out of the
admissible range that is [3 - 21] mA
Check the electrical connection of the
Lwt Reset signal.
Check the device that produces the
Lwt Reset signal.
6.1.1.3 Bad Demand Limit Input Signal
This alarm can occurs only when the function Demand Limit is enabled (see section 0). It indicates
that the Demand Limit signal input is out of admissible range
Symptom
Cause
Solution
Unit status is Run.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+DemandLimitAlm
String in the alarm log:
DemandLimitAlm
String in the alarm snapshot:
DemandLimit Alm
Demand Limit input signal is out of
the admissible range that is [3 - 21]
mA
Check the electrical connection of the
demand limit signal.
Check the device that produces the
demand limit signal
6.1.1.4 Heat Recovery Entering Water Temperature (HREWT) sensor fault (A/C only)
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:
+UnitAlHREwtSen
String in the alarm log:
UnitAlHREwtSen
String in the alarm snapshot:
UnitAlHREwtSen
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.
6.1.1.5 Heat Recovery Leaving Water Temperature (HREWT) sensor fault (A/C only)
This alarm is generated any time the input resistance is out of an acceptable range.
Symptom
Cause
Solution
