Siemens SIMATIC ET 200AL System Manual page 30

Components and protective measures
Various components and protective measures are stipulated for setting up a complete plant.
The types of components and the degree to which the protective measures are mandatory
depend on the IEC regulation that applies to your plant setup.
The following table shows the components of the electrical configuration with reference to
the previous figure and compares the IEC regulations.
Table 5- 1
Disconnection ele-
ment for controller,
sensors, and actua-
tors
Short-circuit / over-
load protection
Cable protection
Insulation monitoring
In the following situations, you must provide insulation monitoring.
● When configuring the ET 200AL distributed I/O system with non-grounded reference
potential
● When hazardous system conditions may occur due to errors
Distributed I/O system
System Manual, 08/2019, A5E31861578-AG
5.2 Operation of the ET 200AL on grounded/non-grounded infeed
Components of electrical configuration
Reference to
illustration
①
②
③
IEC 60364
(DIN VDE 0100)
Main switch
Single-pole protection of
circuits
Secure all incoming supply
cables with a circuit breaker
(24 V DC/4 A).
Protection of cables and
wires against overcurrent
Connecting
IEC 60204
(DIN VDE 0113)
Disconnector
Secure with one pole with a
grounded secondary circuit
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