Siemens SIMATIC ET 200M Operating Instructions Manual page 57

Filtering the 24 V DC supply
If, with a configuration with ungrounded reference potential, you supply the IM 153-x from a
battery, you must suppress the 24 V DC power supply. To do this, use a Siemens mains
filter, e.g. B84102-K40.
Insulation monitoring
If, on account of double faults, dangerous situations could occur, then you must provide
insulation monitoring.
3.6.4 Configuration of the ET 200M with isolated modules
Definition
With a configuration using isolated modules, the reference potentials are electrically isolated
from the control circuit (M
Application area
You use electrically isolated modules for:
● all AC load circuits
● DC load circuits with separate reference potential, e.g.
Isolated modules and grounding concept
You can use isolated modules irrespective of whether the reference potential of the ET 200M
is grounded or not.
ET 200M
Operating Instructions, 12/2008, EWA-4NEB780600602-08
internal
– DC load circuits, the encoders for which have different reference potentials (e.g. if
grounded encoders are used far away from the controller and an equipotential
bonding isn´t possible)
– DC power circuits, the positive poles (L +) of which are grounded (battery circuit).
) and load circuit (M
external
Assignment planning
3.6 Configuring the electrical structure
) (refer also to the following figure).
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