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000061BG
5 - Installation
O
perations preparatory to PV generator connection
C
hecking the correct polarity of the strings
Using a voltmeter, check that the voltage of each string observes the
correct polarity and falls within the input voltage limits accepted by the
inverter (see technical data).
Inversion polarity can cause serious damage
If the voltage without load of the string is near the maximum value ac-
cepted by the inverter, it must be borne in mind that with low ambient
temperatures the string voltage tends to increase (in a different way ac-
cording to the photovoltaic module used). In this case, it is necessary to
carry out a check of the
sizing of the system and/or a check on the con
-
nections of the modules of the system (e.g.: number of modules in series
higher than the design number).
C
hecking of leakage to ground of the photovoltaic generator
Measure the voltage present between positive and negative pole of each
string with respect to ground.
If a voltage is measured between an input pole and ground, it may be that
there is a low insulation resistance of the photovoltaic generator and the
installer will have to carry out a check to solve the problem.
Do not connect the
strings if a leakage to ground has been found because the inverter might
not connect to the grid.
R
equirements of the PV generator
If the PV generator is made up of two or more strings it is necessary
to remember that they must be formed by PV modules which have the
same type and number of panels in series. In addition, they must have
the same installation conditions (in terms of orientation in relation to the
SOUTH and inclination in relation to the horizontal plane)
All input parameters that must be met for the correct operation of the
inverter are shown in the specifications.
C
hoice of differential protection downstream of the inverter
Based on the current CEI 64-8 Norms and Variant 4 (V4) of September
2006, which in Section 712: “Solar photovoltaic power systems (PV)”
addresses photovoltaic applications, with particular reference to para-
graph 712.413: “Protection against indirect contact”, the following may
be noted:
