44
Connecting combined Solar Module Strings
using a DC String Input Combiner
Additional required components
Option
General
Additional
Required
Components
- 2 string input combiners
(available from Fronius as an
option)
- cable lugs
select cable lugs that match the
available DC cables
- hexagon screws
- hexagon nuts
matching the cable lugs
The following additional components are required for connecting combi-
ned solar module strings using a DC string input combiner:
When more solar module strings are combined to one solar module string
prior to the inverter, the solar module string current may exceed the per-
missable DC input terminal current rating of 20 A.
In this case the DC cables can be connected to the Fronius IG Plus using
a string input combiner as an option.
The Fronius IG Plus is designed for a solar module ground at the negative
pole. The solar module ground is carried out via a fuse in the inverter.
Solar Module
Ground
=
~
=
~
DC+
DC-
Inverter
N
L1
GND
Solar module
Solar module ground at negative pole with fuse
DC main switch
L3
L2
GFDI fuse
String fuse