Use With Solar Modules That Have To Be Grounded - Delta RPI M50A_120 Installation And Operation Manual

5 Planning the installation
5.8.3 Use with solar modules that have to be
grounded.
NOTICE
Machine and equipment damage
may occur.
► When the DC inputs are grounded,
all of the strings must be connected
in parallel and then connected to
the inverters.
► Additionally, an external isolation
transformer must be installed on
the AC side, otherwise, damage will
result and the inverter will not work
properly.
When the DC inputs are grounded, all of the strings
must be connected in parallel and then connected to
the inverter(s).
AC wiring
Utility
3-phase, 230/400 V
star or delta connection
Isolated
transformer
Inverter
230/400 V
3P3W 3P4W
1 - L1 1 - L1
2 - L2 2 - L2
3 - L3 3 - L3
4 - N - PE
5 - PE
OFF
DISCONN.
AC/DC
Fig. 5.16: System design with positive or negative grounding of the solar modules
28
AC
Distribution Box
+
AC
–
–
ON
AC OUTPUT
When the solar modules need to be grounded, an
external isolation transformer has to be implemented
to the AC side of the PV system as shown in
5.16, p. 28.
Depending on the DC connection type, different set-
tings for insulation detection are needed, see
Insulation mode and insulation resistance", p.
You have to prepare the inverter for use with
grounded solar modules, see
Fig. 5.18, p. 30. Because you have to remove the
cover of the fuse section, you should do this before
you hang the inverter on the wall and do it in a dry
environment. For a detailed description how to do
this, see "6.5 Connecting to the solar modules (DC)",
p. 42.
PV array
DC wiring
+ – + – + –
DC 1 DC 2
DC INPUT
Fig. 5.17, p. 29
Positive grounding
Z
Negative grounding
Z
Parallel DC inputs only
+
COMM.
Installation and Operation Manual for RPI M50A
Fig.
"8.7
59.
and