Air and Water cooled inverter chillers and heat pump
D-EOMZC00105-17EN
Operation Manual
80/84
EWAD TZ - EWAD TZ B -EWWD VZ
Air and Water cooled inverter chillers and
heat pump
EEXV is not working correctly.
It’s not opening enough or it’s moving in
the opposite direction.
Check if pump-down can be finished for
pressure limit reached;
Check expansion valve movements.
Check connection to the valve driver on the
wiring diagram.
Measure the resistance of each winding, it
has to be different from 0 Ohm.
Reset
Notes
Local HMI
Network
Auto
6.6.23 No Pressure At Start Alarm
This alarm is used to indicate a condition where the pressure at the evaporator or at the condenser is lower
than 35kPa, so the circuit is potentially empty of refrigerant.
Symptom
Cause
Solution
Circuit status is Off.
The compressor does not start
Bell icon is moving on controller’s display.
String in the alarm list:
Cx OffNoPressAtStart
String in the alarm log:
Cx OffNoPressAtStart
String in the alarm snapshot
Cx OffNoPressAtStart
Evaporator or condenser pressure are
below 35kPa
Check transducers calibration with an
appropriate gauge.
Check transducers cabling and readout.
Check refrigerant charge and set it to the
proper value.
Reset
Notes
Local HMI
Network
Auto
6.6.24 No Pressure Change At Start Alarm
This alarm indicates that the compressor is not able to start or to create a certain minimum variation of the
evaporating or condensing pressures after start.
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 OffNoPressChgStart
String in the alarm log:
Cx OffNoPressChgStart
String in the alarm snapshot
Cx OffNoPressChgStart
Compressor cannot start
Check if the start signal is properly
connected to the inverter.
Compressor is turning in wrong direction.
Check correct phases sequence to the
compressor (L1, L2, L3) according to the
electrical scheme.
Inverter is not properly programmed with
the right direction of rotation
Refrigerant circuit is empty of refrigerant.
Check circuit pressure and presence of
refrigerant.
Not proper operation of evaporating or
condensing pressure transducers.
Check proper operation of evaporating or
condensing pressure transducers.
Reset
Notes
Local HMI
Network
Auto
6.6.25 Overvoltage Alarm
This alarm indicates that chiller supply voltage exceeded the maximum limit which allows proper operations of
the components. This is estimated looking at the DC voltage on the inverter which depends of course from the
main power.
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.