EN
128
- Error code
- Error message
- LED status
Name of Alarm and Cause
Solution
- E025
- Riso Low
- Red LED
Low value of isolation resistance:
Before connecting to the grid the inverter
measures the isolation resistance of
the PV generator compared to ground.
Should the measurement of the isolation
resistance be below 75kOhm, the inverter
does not connect to the grid and shows the
“Riso Low” error. The causes may be:
- Damaged PV panel(s).
- Junction box(es) of the panels not
correctly sealed, so as to permit infiltration
by water and/or humidity;
- Problems in connections between panels
(not perfectly fit);
- Poor quality of cable joints;
- Presence in the DC section of unsuitable
or damaged overvoltage surge arresters
outside the inverter (reduced ignition
voltage compared to the characteristics of
the strings of the PV generator);
- Presence of humidity inside any junction
box
• Measure the isolation resistance using a megohmmeter
positioned in the photovoltaic array (positive terminal short-
circuited at the negative pole) compared to ground. The
measurement is strongly influenced by the environmental
conditions, so must be made under the same conditions in
which the error occurred.
- If the value measured is lower than 75kOhm, a check must
be carried out by a technician/installer on the photovoltaic
generator to identify and eliminate the problem.
- If the value measured is higher than 75kOhm and the error
signal persists, contact customer assistance.
- E026
- Internal error
- Yellow LED
Internal reference voltage outside of range:
Wrong measurement of reference voltage
inside inverter
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E027
- Internal error
- Yellow LED
Grid voltage outside of range:
Error in the internal measurement of grid
voltage (set by law) to have a redundant
measurement (2 measurements on the
same parameter made by two different
circuits)
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E028
- Internal error
- Yellow LED
Grid frequency outside of range:
Error in the internal measurement of the
grid frequency (imposed by regulations)
to have a measurement redundancy (2
measurements on the same parameter
carried out by two different circuits).
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E029
- Mid Bulk OV
- Yellow LED
Internal overvoltage on the measurement
of the “Mid bulk”:
Error inside the inverter (only triphase
models)
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E030
- Internal error
- Yellow LED
High leakage current (DC side):
- Error on the internal measurement
(performed when the inverter is
connected to the grid) of the DC side (PV
generator) leakage current with respect
to ground (required by regulations) to
have a measurement redundancy (2
measurements of the same parameter
carried out by two independent circuits)
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E031
- Internal error
- Yellow LED
Output relay damaged:
Measurement of internal voltage on heads
of the output relay outside of range. There
is too great a difference in voltage between
the input and output of the grid connection
relay.
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
- E032
- Internal error
- Yellow LED
Imbalanced output currents:
Measurement of the unbalance in the
output voltage (made across the three
phases) outside of range (only in three-
phase models)
• Error inside the inverter and cannot be checked externally.
- If the problem persists (once the inverter has been switched
off and back on again), contact customer assistance.
