Unit Rapid Stop Alarms - Daikin MICROTECH III Operating Manual

10.4 Unit Rapid Stop Alarms

10.4.1 Phase Volts Loss/GFP Fault
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
Unit status is Off.
All circuits are stopped immediately.
Bell icon is moving on controller's
display. String in the alarm list:
UnitOffPhaveVoltage
String in the alarm log:
UnitOffPhaveVoltage
String in the alarm snapshot
UnitOffPhaveVoltage
Reset
Local HMI
Network
Auto
10.4.2 Evaporator Flow Loss
This alarm is generated in case of flow loss to the chiller to protect the machine against freezing.
Symptom
Unit status is Off.
All circuits are stopped immediately.
Bell icon is moving on controller's
display. String in the alarm list:
UnitOffEvapWaterFlow String in the
alarm log:
± UnitOffEvapWaterFlow
String in the alarm snapshot
UnitOffEvapWaterFlow
Reset
Local HMI
Network
Auto
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Cause
Loss of one phase.
Not correct sequence connection of
L1,L2,L3.
Voltage level on the unit's panel is not
in the allowed range (±10%).
There is a short-circuit on the unit.
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Cause
No water flow sensed for 3 minutes
continuously or water flow too low.
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Operation Manual
Solution
Check voltage level on each of the
phases.
Check sequence of L1, L2, L3
connections according indication on
chiller's electrical scheme.
Check that voltage level on each
phases is into the allowed range that
is indicated on the chiller label.
Is important to check the voltage
level on each phases not only with
chiller not running, but mainly with
chiller running from minimum
capacity up to full load capacity.
That's because voltage drop can
occur from a certain unit cooling
capacity level, or because of certain
working condition (i.e. high values of
OAT); In these cases the issue can
be related with the sizing of power
cables.
Check for correct electrical isolation
condition of each unit's circuit with a
Megger tester.
Notes
Solution
Check the water pump filler and the
water circuit for obstructions.
Check the flow switch calibration and
adapt to minimum water flow.
Check if pump impeller can rotate
freely and has no damages.
Check pumps protection
(circuit breakers, fuses, inverters, etc.)
Check if water filter is clogged.
Check flow switch connections.
Notes
D–EOMWC00A07-16_02EN
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