• For supply voltage cables (24 V DC) and signals:
If there is a risk of overvoltage, you need to provide lightning protection measures for internal
lightning protection (e.g. lightning protection elements).
• SIMATIC CN 4100 in LAN networks:
In LAN networks (Local Area Networks), you may only operate the SIMATIC CN 4100 with
RJ45 interfaces if the following condition is met:
All connected nodes must be operated with SELV/PELV type voltage supplies (e.g. power
supply unit, battery) with safe electrically isolated functional extra-low voltage.
Line voltage
Observe the following for the line voltage:
• A disconnector (all-pole) must be provided in the building installation for xed plants or
systems without all-pole disconnectors.
• For the power supply, the congured rated voltage range must correspond to the local line
voltage.
• The uctuation/deviation of the line voltage from the rated value must be within the
permissible tolerance for all circuits of the SIMATIC CN 4100.
Information on insulation, protection class, degree of protection and rated voltage (Page 63)
Protection against external electrical inuences
Observe the following for protection against electrical inuences or faults:
• For all plants with SIMATIC CN 4100, ensure that the plant is connected to a protective
conductor with sucient cross-section to dissipate electromagnetic interference.
6.2 Notes on wiring
The modules are supplied with the voltage potentials 24 V DC and M via the input terminals of
the rack. The terminal blocks for supplying the L+ and M potentials are arranged on the rack.
Connecting
6.2 Notes on wiring
CN 4100 Communication System
36 Equipment Manual, 10/2021, A5E50871363-AA