Huawei MERC-1300W-P - Page 7

6
Voltage
Cause
Suggestion
The PV string
voltage is 0.

The PV string is open-circuited.

The cables are not connected to the
same PV string.
1.
Check whether the PV string is open-
circuited.
2.
Identify the string cables correctly.
The PV string
voltage is a
negative value.

The probes are reversely connected.

The cable labels are incorrect.
1.
Reconnect the positive and negative
probes correctly.
2.
Prepare cable labels correctly.
The value of PV
string voltage
is less than the
number of
optimizers.

Some optimizer input power cables
are not connected.

Some optimizer output power
cables are not connected.

Some optimizer output power
cables are reversely connected.
Check whether PV modules and PV
string cables are correctly connected.
The value of PV
string voltage
is greater than
the number of
optimizers.

The actual number of optimizers in
the string is greater than expected.

PV modules are directly connected
to PV strings without being
connected to optimizers.
1.
Check whether the number of
optimizers in the PV string is correct.
2.
Check whether PV modules and PV
string cables are correctly connected.
3. Check that the optimizer and its input cables are properly connected, and then connect the
optimizer output power cables. Measure the PV string voltage when the sunlight is sufficient.
Configuration Scenarios
PV string