Siemens SIMATIC S7-1500 Automation System System Manual page 56

Wiring
6.2 Operating the S7-1500 on grounded infeed
Short-circuit and overload protection
Various measures as protection against short-circuits and overloads are required for setting
up a full installation. The nature of the components and the degree to which the required
measures are binding depends on the IEC (DIN VDE) regulation applicable to your plant
configuration. The table refers to the following figure and compares the IEC (DIN VDE)
regulations.
Table 6- 1 Components and required measures
Shut-off device for control system,
sensors, and actuators
Short-circuit and overload protection:
In groups for sensors and actuators
Load power supply for AC load circuits
with more than five electromagnetic
devices
56
Reference to
following figure
①
Main switch
② Single-pole protection of
circuits
③
④ Galvanic isolation by
transformer recommended
IEC 60364
(DIN VDE 0100)
Disconnector
•
•
Galvanic isolation by
transformer recommended
System Manual, 01/2013, A5E03461182-01
IEC 60204
(DIN VDE 0113)
With grounded
secondary circuit: fuse
unipolar
otherwise: fuse all
poles
S7-1500 Automation System