Siemens SIMATIC ET 200SP System Manual page 46

Please note:
● The potential groups opened with a light-colored PotDis-BU must not contain any I/O
modules. You can integrate any dark-colored PotDis-BUs into I/O module potential
groups provided they are based on an SELV/PELV supply.
● If you do not need the additional terminals of the PotDis-TB in a potential distributor
module, replace the PotDis-TB with a BU cover. You may only connect one potential
group within a combination of PotDis-BU and PotDis-TB.
● Only SELV/PELV potentials are permitted on PotDis-BUs. Separate different SELV/PELV
potential groups using light-colored PotDis-BUs.
● With potential distributor modules, you may only connect to the PotDis-TB versions BR-W
and n.c.-G potential, which exceed the voltage level of SELV/PELV.
● PotDis terminals are not directly configurable as PotDis via GSD/GSDML. When
configuring with GSD, always use an dummy module; with GSDML, integrate a free
space.
Additional information
Additional information on the potential distributor modules (PotDis-BaseUnits and PotDis-
TerminalBlocks) is available in the BaseUnits
(http://support.automation.siemens.com/WW/view/en/59753521) manual.
Distributed I/O system
System Manual, 09/2019, A5E03576849-AJ
Application planning
4.3 Selecting potential distributor modules
45