Operation Of The Et 200Al On Grounded/Non-Grounded Infeed - Siemens SIMATIC ET 200AL System Manual

5.2

Operation of the ET 200AL on grounded/non-grounded infeed

Introduction
Information is provided below on the overall configuration of an ET 200AL distributed I/O
system on a grounded incoming supply (TN-S network). The specific subjects discussed are:
● Disconnecting devices, short-circuit and overload protection to IEC 60364 (corresponding
to DIN VDE 0100) and IEC 60204 (corresponding to DIN VDE 0113)
● Load current supplies and load circuits
● Supply voltages of the ET 200AL distributed I/O system
Grounded infeed
In grounded incoming supplies, the neutral conductor of the supply system is grounded. A
simple ground fault between a live conductor and ground or a grounded section of the plant
causes the protective devices to trip.
Supply voltages
Two SELV/PELV supply voltages are available for the ET 200AL distributed I/O system.
● 1L+: Supply voltage (non-switched)
● 2L+: Load voltage (switched)
Secure electrical separation (SELV/PELV according to IEC 61010-2-201)
Mains devices/power supply modules with secure electrical separation are required for the
operation of the ET 200AL distributed I/O system. This protection is designated as SELV
(Safety Extra Low Voltage)/PELV (Protective Extra Low Voltage) according to
IEC 60364-4-41.
Configuring ET 200AL with grounded reference potential
When configuring the ET 200AL distributed I/O system with grounded reference potential,
occurring interference currents are discharged into functional earth. The connections must
be externally connected (connection between 1M and FE).
Configuring ET 200AL with ungrounded reference potential
When configuring the ET 200AL distributed I/O system with non-grounded reference
potential, occurring interference currents are discharged via an internal RC network to
functional earth (no external connection between 1M and FE).
Distributed I/O system
System Manual, 08/2019, A5E31861578-AG
5.2 Operation of the ET 200AL on grounded/non-grounded infeed
Connecting
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