Installing network components in cabinets
3.3 Guidelines for setting up networked automation systems in buildings
Passive network components
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Figure 3-7
Contacting the shield at the point of entry to a cabinet
3.3.6.4
Special noise suppression measures
Connecting switched inductances to suppressors
Some inductive switching devices (for example relays) create interference voltages that are
a multiple of the connected operating voltage. The SIMATIC S7-300 /9/ and S7-400 /10/
system manuals contain suggestions on how to limit the interference voltages caused by
inductance by connecting them to suppressors.
Power supply for programming devices
It is advisable to include a power socket for programming devices in each cabinet. The
socket must be supplied by the same system to which the PE conductor for the cabinet is
connected.