Daikin EWAT_B - 5.3 Unit Rapid Stop Alarms; 5.3.1 UnitOffEvap WaterTmpLow - Evaporator Water Temperature Low alarm; 5.3.2 UnitOff ExternalAlarm - External alarm; 5.3.3 PVM alarm (A;C units only)

Operating Manual
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EWAT_B
UnitOffAmbTempSen
Check for correct plug-in of the electrical
connectors.
Check for correct sensors wiring also
according electrical scheme.
Reset
Local HMI
Network
Auto



5.3 Unit Rapid Stop Alarms
All alarms reported in this section produce an instantaneous stop of the unit.
5.3.1 UnitOffEvapWaterTmpLow - Evaporator Water Temperature Low alarm
This alarm is generated to indicate that the water temperature (entering or leaving) has dropped below a safety limit.
Control tries to protect the heat exchanger starting the pump and letting the water circulate.
Symptom
Cause
Solution
Unit status is Off.
All circuits are stopped immediately.
Bell icon is moving on controller’s display.
String in the alarm list:
UnitOff EvapWaterTmpLow
String in the alarm log:
 UnitOff EvapWaterTmpLow
String in the alarm snapshot
UnitOff EvapWaterTmpLow
Water flow too low.
Increase the water flow.
Inlet temperature to the evaporator is too
low.
Increase the inlet water temperature.
Flow switch is not working or no water flow.
Check the flow switch and the water pump.
Sensors readings (entering or leaving) are
not properly calibrated.
Check the water temperatures with a
proper instrument and adjust the offsets
Wrong freeze limit setpoint.
The freeze limit has not been changed as
a function of glycol percentage.
Reset
Local HMI
Network
Auto



5.3.2 UnitOff ExternalAlarm - External alarm
This alarm is generated to indicate that an external device whose operation is linked with this unit operation. This external
device could be a pump or an inverter.
Symptom
Cause
Solution
Unit status is Off.
All circuits are switched off with the normal
shutdown procedure.
Bell icon is moving on controller’s display.
String in the alarm list:
UnitOff ExternalAlarm
String in the alarm log:
 UnitOff ExternalAlarm
String in the alarm snapshot
UnitOff ExternalAlarm
There is an external event that has caused
the opening, for at least 5 seconds, of the
port on the controller board.
Check causes of the external event or
alarm.
Check electrical wiring from unit controller
to the external equipment in case of any
external events or alarms have been
occurred.
Reset
Local HMI
Network
Auto



5.3.3 PVM alarm (A/C units only)
This alarm is generated in case of problems with the power supply to the chiller.
Resolution of this fault requires a direct intervention on the power supply of this unit.
Direct intervention on the power supply can cause electrocution, burns or even death. This action must be
performed only by trained persons. In case of doubts contact your maintenance company.
Symptom
Cause
Solution
Unit status is Off.
All circuits are stopped immediately. Bell
icon is moving on controller’s display.
String in the alarm list:
UnitOff PVM
String in the alarm log:
 UnitOff PVM
String in the alarm snapshot
Loss of one phase.
Check voltage level on each of the phases.
Not correct sequence connection of
L1,L2,L3.
Check sequence of L1, L2, L3 connections
according indication on chiller’s electrical
scheme.
Voltage level on the unit’s panel is not in
the allowed range (±10%).
Check that voltage level on each phases is
into the allowed range that is indicated on
the chiller label.