Operating The Et 200X With Reference Potential - Siemens SIMATIC ET 200X Manual

Configuring the ET 200X with ungrounded reference potential
When the ET 200X is configured with ungrounded reference potential, any
interference currents that occur are diverted to the protective ground via an RC
network in the basic module.
Insulation monitor
You must set up an insulation monitor in the following cases:
S Ungrounded configuration of the ET 200X
S When dangerous system states can occur as a result of double faults
ET 200X in overall configuration
Figure 4-1 shows the location of the ET 200X distributed I/O device in the overall
system (load power supply and grounding philosophy) for supply from a TN-S
system.
L1
L2
L3
N
PE
In the case of the ET 200X-DESINA
and ET 200X-ECOFAST:


DC 24 V-NS

In an ungrounded ET 200X
configuration, there is no con
nection between 1M and PE.

AC
DC
Figure 4-1

Operating the ET 200X with reference potential

ET 200X Distributed I/O Device
EWA 4NEB 780601602-06
1L+
AC
1M
DC
Ground bus
Low-voltage distribution
For example, TN-S system
(3 400 V)
ET 200X
BM
mP

Load circuit
AC 400V for motor starters and
frequency converters

24 VDC load circuit for digital and analog
outputs and motor starters (fed via connectors
on basic module)
Wiring
Data
M
internal
4-5