Siemens SIMATIC RF300 System Manual page 115

4.6.5 Cabinet configuration
The influence of the user in the configuration of an electromagnetically compatible plant
encompasses cabinet configuration, cable installation, ground connections and correct
shielding of cables.
For information about electromagnetically compatible cabinet configuration, please consult the
installation guidelines for SIMATIC PLCs.
Shielding by enclosure
Magnetic and electrical fields and electromagnetic waves can be kept away from the
interference sink by using a metal enclosure. The easier the induced interference current can
flow, the greater the intrinsic weakening of the interference field. All enclosures and metal
panels in the cabinet should therefore be connected in a manner allowing good conductance.
Figure 4-11
If the control cabinet panels are insulated from each other, a high-frequency-conducting
connection can be established using ribbon cables and high-frequency terminals or HF
conducting paste. The larger the area of the connection, the greater the high-frequency
conductivity. This is not possible using single-wire connections.
Prevention of interference by optimum configuration
Good interference suppression can be achieved by installing SIMATIC PLCs on conducting
mounting plates (unpainted). When setting up the control cabinet, interference can be
prevented easily by observing certain guidelines. Power components (transformers, drive units,
load power supply units) should be arranged separately from the control components (relay
control unit, SIMATIC S7).
SIMATIC RF300
System Manual, 02/2021, C79000-G8976-C345-09
Shielding by enclosure
4.6 Guidelines for electromagnetic compatibility (EMC)
Planning the RF300 system
115