Zapi DUALACE2 NEW GENERATION User Manual page 144

Cause
The logic board measures a voltage value across the DC-link that is constantly
out of range, above the maximum allowed value.
Troubleshooting
Check that the battery has the same nominal voltage of the inverter.
Check the battery voltage, if it is out of range replace the battery.
If the battery voltage is ok, replace the logic board.
VKEY OFF SHORTED (MDI/LED code = 20)
Cause
At key-on, the logic board measures a voltage value of the KEY input that is
constantly out of range, below the minimum allowed value.
Troubleshooting
Check that the battery has the same nominal voltage of the inverter.
Check the battery voltage, if it is out of range replace the battery.
If the battery voltage is ok, replace the logic board.
VMN HIGH (MDI/LED code = 31)
Cause 1
Before switching the LC on, the software checks the power bridge: it turns on
alternatively the low-side power MOSFETs and expects the phase voltages
decrease down to -B. If the phase voltages are higher than a certain percentage
of the nominal battery voltage, this alarm occurs.
Cause 2
This alarm may also occur when the start-up diagnosis has succeeded and so
the LC has been closed. In this condition, the phase voltages are expected to be
lower than half the battery voltage. If one of them is higher than that value, this
alarm occurs.
Troubleshooting
If the problem occurs at start-up (the LC does not close), check:
motor internal connections (ohmic continuity);
motor power cables connections;
if the motor connections are OK, the problem is inside the controller. Replace it.
If the alarm occurs while the motor is running, check:
motor connections;
that the LC power contact closes properly, with a good contact;
if no problem is found, the problem is inside the controller. Replace it.
VMN LOW (MDI/LED code = 30)
Cause 1
Start-up test. Before switching the LC on, the software checks the power bridge:
it turns on alternatively the high-side power MOSFETs and expects the phase
voltages increase toward the positive rail value. If one phase voltage is lower
than a certain percentage of the rail voltage, this alarm occurs.
Cause 2
Motor running test. When the motor is running, the power bridge is on and the
motor voltage feedback tested; if it is lower than expected value (a range of
values is considered), the controller enters in fault state.
Troubleshooting
If the problem occurs at start up (the LC does not close at all), check:
AFNZPxxx – DUALACE2 NEW GENERATION – User Manual
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