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
74
EWWQ - EWLQ - EWHQ
EWAQ - EWYQ
Air or Water cooled scroll chiller &
heat pump
D-EOMHW00107-15EN
6.1.5 Circuit Warning Alarms
The following alarms will stop the circuit immediately but will allow the circuit to restart when the
anti-recycle timers are expired.
6.1.5.1 Low Outside Ambient Temperature At Start Alarm
This alarm can occurs only if the condenser less unit type is configured or if the unit is A/C (see
section 0). It indicates that the circuit is starting with low outside ambient temperature.
Symptom
Cause
Solution
Circuit status is Off.
The circuit is stopped.
Bell icon is moving on controller’s
display.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+Cx LowOatStartAlm
String in the alarm log:
Cx LowOatStartAlm
String in the alarm snapshot:
Cx LowOatStart Alm
Low outside ambient temperature
Check the operating condition of the
condenser-less unit.
Refrigerant charge low.
Check sight glass on liquid line to see
if there is flash gas.
Measure sub-cooling to see if the
refrigerant charge is correct.
6.1.5.2 Failed Pumpdown
This alarm is generated to indicate that the circuit hadn’t been able to remove all the refrigerant
from the evaporator.
Symptom
Cause
Solution
Circuit status is Off.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+Cx FailedPumpdownAlm
String in the alarm log:
Cx FailedPumpdownAlm
String in the alarm snapshot:
Cx FailedPumpdown Alm
EEXV is not closing completely,
therefore there’s “short-circuit”
between high pressure side with low
pressure side of the circuit.
Check for proper operation and full
closing position of EEXV. Sight glass
should not show refrigerant flow after
the valve is closed.
Check that the C-LED on the EXV
driver is solid green. If both LEDs on
the EXV driver are blinking alternately
the valve motor is not properly
connected.
Evaporating pressure sensor is not
working properly.
Check for proper operation of
evaporating pressure sensor.
Compressor on circuit is internally
damaged with a mechanical problems
for example on internal check-valve,
or on internal spirals or vanes.
Check compressors on circuits.
6.1.5.3 Failed Pumpdown in High Pressure (A/C only)
This alarm is generated to indicate that the circuit hadn’t been able to remove all the refrigerant
from the evaporator before getting too close to the High Pressure alarm limit. In this case the
pumpdown is finished before the pumpdown pressure target is reached.
Symptom
Cause
Solution
Circuit status is Off.
Led on the button 2 of External HMI is
blinking
String in the alarm list:
+Cx FailedPumpdownHiPr
String in the alarm log:
Excessive refrigerant charge
Verify the refrigerant charge by
checking the subcooling
