Assignment planning
3.6 Configuring the electrical structure
ET 200M
50 Operating Instructions, 12/2008, EWA-4NEB780600602-08
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
and DIN VDE 0113
● 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 DIN VDE-directives for the configuration of a controller
Comparisons ... Reference to
figure
DIN VDE 0100 DIN VDE 0113
Switch-off organ for
controllers, signal sensors
and final control elements
(1) … part 460:
Main switch
… part 1:
Separator
Short-circuit and overload
protection:
in groups for signal sensors
and final control elements
(2) … part 725:
Single-pole protection
of the circuit
… part 1:
• with grounded
secondary power
circuit:
single-pole protection
• otherwise: all-pole
protection
Load power supply for AC
load circuits with more than
five electromagnetic
apparatus
(3) metallic isolation with
transformers
recommended
metallic isolation with
transformers required
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