Siemens SIMATIC S7-1500 System Manual page 70

Wiring
5.3 Operation 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 5- 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 current supply for AC load cir-
cuits with more than five electromag-
netic devices
70
R e fe re n ce to
fo llowi n g fi g u re (D IN VD E 0 1 0 0 )
①
Main switch
② Single-pole protection of
circuits
③
④ Galvanic isolation by
transformer recommended
IEC 6 0 3 6 4 IEC 6 0 2 0 4 (D IN VD E 0 1 1 3 )
Disconnector
With grounded secondary
•
circuit: fuse u n ipolar
Otherwise: fuse a l l poles
•
Galvanic isolation by transformer
re commended
System Manual, 09/2016, A5E03461182-AD
Automation system