12
5.7 Power distribution box with residual
current device
Power distribution boxes equipped with an AC/DC sensitive
residual current device
(FI/RCD) type B/B+
, must only be
connected to and operated with electrical installations that
have a suitable back-up fuse.
Devices with such a circuit breaker are suitable for opera-
tion with frequency-controlled consumers (e. g. welding
systems, compactors).
These power distribution boxes have the following sticker:
Sticker
Connect a power distribution box with the shown sticker
only to electrical installations that have a suitable back-
up fuse.
WARNING
Incorrect installation / Unsuitable back-up fuse – Risk
of injury due electric shock
A residual current device (FI/RCD) of type AC/A of a given
electrical installation can, in the event of a fault, become
inoperative due to an impermissible switching sequence,
if this device is connected to a power distribution box
with a residual current device (FI/RCD) of type B/B+. The
protective function of the circuit breaker is thus no longer
given.
Connect a power distribution box with a residual cur-
rent device (FI/RCD) of type B/B+ only
upstream
of
the residual current device (FI/RCD) of type AC/A of an
electrical installation.
If you are uncertain, have a qualified electrician check
the electrical installation for suitability.
5.7.1 Correct
installation
Installation diagram
The example shows that the residual current device (FI/RCD)
of type B/B+ is connected
upstream
of the residual current
device (FI/RCD) of type A/AC.
Correct installation
