Protection of people and equipment
Central grid and
system protec-
tion
The inverter offers the option to use the integrated AC relays as coupling
switches in conjunction with a central grid and system protection unit (in accord-
ance with VDE-AR-N 4105:2018:11 §6.4.1). For this purpose, the central trigger
device (switch) must be integrated into the WSD chain as described in the
chapter "WSD (Wired Shut Down)".
WSD (wired
shutdown)
The wired shutdown (WSD) interrupts the inverter feeding energy into the grid if
the trigger device (switch) has been activated.
If an inverter (secondary device) fails, it is bypassed and the other inverters con-
tinue operating. If a second inverter (secondary device) or the inverter (primary
device) fails, the operation of the entire WSD chain is interrupted.
For installation, see Installing the WSD (wired shutdown) on page 93.
RCMU The inverter is equipped with a universal current-sensitive residual current monit-
oring unit (RCMU = Residual Current Monitoring Unit) in accordance with IEC
62109-2.
This device monitors residual currents from the PV module to the AC output of
the inverter and disconnects the inverter from the grid in the event of unauthor-
ised residual current.
Surge protective
device
The inverter is equipped with an integrated surge protective device on the DC
and AC side in accordance with IEC 62109-2. The surge protective device pro-
tects the system against damage in the event of an overvoltage.
30