Siemens SIMATIC ET 200M Operating Instructions Manual page 52

Assignment planning
3.6 Configuring the electrical structure
3.6.2 Operating the ET 200M with process I/O on a grounded supply
The following gives information on the overall configuration of an ET 200M to a grounded
supply (TN-S-network). The topics covered here are:
● Switch-off organs, short-circuit and overload protection in accordance with DIN VDE 0100
● Load power supplies and load circuits
Grounded supply
With grounded supplies the neutral line of the network is grounded. A simple contact to earth
between a live cable and ground or a grounded part of the unit triggers the safety organs.
Components and safety measures
Different components and safety measures are prescribed for setting up a complete plant.
The nature of the components and the degree of credibility of the safety measures depends
on which DIN VDE directive applies to your unit configuration. The following table refers to
the two following figures.
Table 3- 4
Comparisons ...
Switch-off organ for
controllers, signal sensors
and final control elements
Short-circuit and overload
protection:
in groups for signal sensors
and final control elements
Load power supply for AC
load circuits with more than
five electromagnetic
apparatus
50
and DIN VDE 0113
DIN VDE-directives for the configuration of a controller
Reference to DIN VDE 0100
figure
(1) ... part 460:
Main switch
(2) ... part 725:
Single-pole protection
of the circuit
(3) metallic isolation with
transformers
recommended
Operating Instructions, 12/2008, EWA-4NEB780600602-08
DIN VDE 0113
... part 1:
Separator
... part 1:
with grounded
•
secondary power
circuit:
single-pole protection
otherwise: all-pole
•
protection
metallic isolation with
transformers required
ET 200M