Overvoltage Protection - Sputnik Engineering SolarMax 2000S Documentación Del Dispositivo

Back-up fuses and cable cross-sections
Follow the generally accepted state of the art. Start on the AC side.
AC side:
Each inverter must be protected separately! No consumers may be connected be-
tween the fuse and the inverter!
Type
Back-up fuse
(characteristic C)
Minimum
cable cross-section (strand)
We recommend using larger conductor cross-sections in order to minimise line
losses.
The fl exible cable is connected to a junction box with a maximum length of one
metre. From here the installation may be continued with a rigid TT cable.
DC side:
Select the cable cross-sections on the DC side to suit your system confi guration
and in accordance with the relevant installation regulations.
General information:
■
When connecting several SolarMax devices, distribute the inverters over the
three mains phases.
■
AC and DC cables must be suitable for the expected loads, currents and ambient
conditions (temperature, UV, etc.).
■
The personal protection regulations must be followed when the inverter is con-
nected to the AC system.
■
Ensure that the mains cable is de-energised before connecting the device.
■ Verify the polarity before installing the DC side.
■
Ensure short circuit- and earth-leakage-proof connection of the DC cables to
the MC terminals.
■
Caution: Due to the earth-fault monitoring function, neither the minus nor the
plus terminal should be earthed. Otherwise the integrated insulation monitoring
function would prevent grid feeding.
■ Connect the DC side via the MC connectors.
63
2000S 3000S 4200S 6000S
10 A 13 A 20 A 25 A
1.5 mm 2 1.5 mm 2 2.5 mm 2 2.5 mm
Large arcs may be generated if connectors are disconnected on the DC or
the AC side during operation. The AC supply and the DC insulation switch
must therefore be disconnected before removing the connectors.
2
Without a connection to the solar generator the stray current of the inverter is less
than 3.5 mA on the AC side. However, during operation of the solar generator, the
stray current at the inverter may far exceed the value of AC 3.5 mA. In this case a
second, fi xed protective earth connection according to EN 50178 is required. The
cross-section of the second protective earth conductor should have at least the
same cross-section as that of the main terminal.

3.3 Overvoltage protection

SolarMax inverters feature integrated surge protectors at the input and output. On
the DC side 2 surge arresters (varistors) for the plus and minus terminal to earth
are installed. On the AC side a surge arrester (varistor) is installed between the
phase and neutral. All surge arresters meet the requirements of class D according
to VDE 0675-6 or Type 3 according to EN 61643-11.
Note the following if the overvoltage protection on the DC is to be increased:
■ For inverters without galvanic isolation the DC terminals have a potential rela-
tive to earth that may be higher than the peak value of the mains voltage. For
this reason, the response voltage of the surge arrester must be higher than
600 V
peak
> 600 V > 600 V
Earthing (second protective earth connection)
.
The diagram on the right shows
the connection of additional surge
arresters on the DC side.
en
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