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Air and Water cooled inverter chillers and heat pump
EWAD TZ - EWAD TZ B - EWWD VZ
Air and Water cooled inverter chillers
and heat pump
D-EOMZC00105-17EN
Operation Manual
81/84
Symptom
Cause
Solution
Circuit status is Off.
The circuit is stopped.
Bell icon is moving on controller’s display.
String in the alarm list:
Cx OffOverVoltage
String in the alarm log:
Cx OffOverVoltage
String in the alarm snapshot
Cx OffOverVoltage
Chiller main power supply had an up peak
which caused the trip.
Check if main power supply is within the
acceptable tolerance for this chiller
Main power supply setting on the
Microtech III is not suitable with the power
supply in use (A/C units).
Measure the power supply to the chiller
and select the proper value on the
Microtech III HMI.
Reset
Notes
Local HMI
Network
Auto
The alarm clears automatically when the
voltage is reduced to an acceptable limit.
6.6.26 Undervoltage Alarm
This alarm indicates that chiller supply voltage exceeded the minimum limit which allows proper operations of
the components.
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
Circuit status is Off.
The circuit is stopped.
Bell icon is moving on controller’s display.
String in the alarm list:
Cx OffUnderVoltage
String in the alarm log:
Cx OffUnderVoltage
String in the alarm snapshot
Cx OffUnderVoltage
Chiller main power supply had a down
peak which caused the trip.
Check if main power supply is within the
acceptable tolerance for this chiller
Main power supply setting on the
Microtech III is not suitable with the power
supply in use (A/C units).
Measure the power supply to the chiller
and select the proper value on the
Microtech III HMI.
Reset
Notes
Local HMI
Network
Auto
The alarm clears automatically when the
voltage is increased to an acceptable limit.
6.6.27 VFD Communication Failure
This alarm indicates a communication problem with the inverter.
Symptom
Cause
Solution
Circuit status is Off.
The compressor does not load anymore,
circuit is immediately stopped.
Bell icon is moving on controller’s display.
String in the alarm list:
CxCmp1 OffVfdCommFail
String in the alarm log:
CxCmp1 OffVfdCommFail
String in the alarm snapshot
CxCmp1 OffVfdCommFail
RS485 network is not properly cabled.
Check the continuity of the RS485 network
with the unit off. There should be continuity
from the main controller to the last inverter
as indicated on the wiring diagram.
Modbus communication is not running
properly.
Check inverter addresses and addresses
of all the additional devices in the RS485
network (for example the energy meter).
All the addresses must be different.
Modbus interface card can be faulty
Check with your service organization to
evaluate this possibility and eventually
replace the board.
Reset
Notes
Local HMI
Network
Auto
The alarm clears automatically when the
communication is re-established.