If several solar inverters are operated in
parallel, the feed-in phase L1 of the unit
must be evenly distributed over grid pha-
ses L1, L2 and L3 (see Fig. page 107).
You must use adequately dimensioned
cable cross-sections in order to avoid a
considerable increase in the grid impe-
dance between the domestic distribution
and the solar inverter. The terminal range
of the AC terminals is 0.5 to 6 mm2 for
rigid cables and 0.5 to 10 mm2 for flexible
cables. With a high grid impedance,
i.e. with a long line or too small a cross-
section, the voltage increases at the grid
terminal during feed-in.
If the terminal voltage exceeds the per-
missible value, the solar inverter is dis-
con-nected from the grid. In the case of
poorly designed electric grids and high
PV output, this can also result in repeated
switching off and on of individual solar
inverters.
Carefully perform the following steps:
· Check that there is no voltage before
introducing the supply main into the
unit.
· Lead the 5-core AC cable (outer dia-
meter 9 – 17 mm) through the M 32
threaded cable gland.
· Connect cables L1, N, L2, L3 and PE to
the relevant circuit board terminal with
the help of a slot-head screwdriver
(Fig.) Circuit board terminal for fixing
the grid cable
· Tighten the M 32 screw connection, so
that the cable cannot exert any mechani-
cal force on the circuit board terminal.
108
