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000970AG
5 - Installation
C
hecking the correct polarity of the strings and fuses installation
These activity is allow ONLY with the appropriate PPE for carrying out this check (overall resi-
stant to electric arc, dielectric helmet with visor, insulating gloves class 0, Protective overglove
in leather EN420 – EN388 , Safety shoes).
The reverse polarity can cause severe damage.
Depending of the wiring box
02
version installed on the inverter there are
one or two boards for the string fuses:
- SX, SY version:
contains only positive side string fuses board
19
and have
24 string fuses (1 for each strings) that are supplied and have to be installed.
- SX2, SY2 version:
contains both positive side string fuses board
19
and
negative side string fuses board
20
that totally have 48 string fuses (2 for
each strings). Fuses on the negative side string fuses board
20
are already
fitted while the fuses on the positive side string fuses board
19
are supplied
and have to be installed.
19
20
The string fuses are installed inside special safety positioners that allow
easy installation/removal, as well as providing protection from involunta-
ry contact while the inverter is being installed.
Each fuses are associated with a green LED that could be used to check
the correct polarity of the strings.
Procedure for checking the correct polarity of the strings
1.
Check for the absence of installed fuses on the positive side string
fuses board
19
- if present remove it!.
2.
Turn the DC disconnect switches
15
to OFF.
3.
Connect the strings (refer to “Input connection to PV generator (DC
side)” chapter) and check that the GREEN LED corresponding to
each positive fuses activates. The string will turn out to be inver-
ted if the green LED is OFF or, in some circumstances, faintly ON.
Check the strings one by one so to safely check which strings are inver-
ted.
4.
After all the input strings have been checked, remove all connected
strings and check that all LEDs will switch OFF.
5.
Install the fuses (supplied) on the string fuses board
19
with the sup-
plied fuse holders.
6.
Connect all input strings.
