Fronius Symo Series Installation Instructions Manual page 24

Divide the solar module strings between the two MPP tracker inputs (DC+1 and DC+2).
The DC- terminals can be used however you wish, as they are internally connected. A
clearly numbered connection, but also at the DC- terminal, makes it easier to find the
correct string, e.g., during a testing action. Set the MPP tracker 2 to the "On" position
during initial commissioning. The user can of course also do this later in the Basic menu
of the inverter.
Single MPP tracker mode on both MPP tracker inputs:
If the solar module strings are connected to a string combiner box (GAK - generator junc-
tion box) and the distance to the inverter is bridged by means of a DC string, this DC
string can be connected to the inverter as follows.
Jumpering
DC Con Kit 25
The Fronius DC Con Kit 25 (4,251,015) can be used to connect a solar module string
with a cross-section of up to 25 mm² to the inverter.
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DC+1(Pin2) DC+2(Pin1)
With jumpering, the MPP tracker 1 and
MPP tracker 2 can be jumpered together.
This takes place as shown in the image
via the connection DC+1 (Pin2) to DC+2
(Pin1).
IMPORTANT! The MPP tracker 2 must be
set to OFF. This can be checked in the Ba-
sic menu of the inverter.
IMPORTANT! The cable diameter of the
DC connection cable and the jumpering
must be the same. Jumpering of the DC-
terminal is not necessary because it is
jumpered internally.
Set the MPP tracker 2 to "Off" during initial
commissioning. This can also be done
later in the Basic menu of the inverter. By
using the DC Con Kit 25, the DC strings of
the connected DC lines are divided equally
between both inputs.