4-6
ET 200C Distributed I/O Station
EWA 4NEB 812 6119-02b
4.2.2
Ungrounded Configuration
In an ungrounded configuration, there is no connection between the load
power supply (M terminal) and the protective ground conductor (PE). The
protective ground conductor loses its protective function.
The internal design of the digital and analog modules is such that the supply
voltage is connected to the protective ground conductor through a capacitor,
in order to dissipate high-frequency interference.
For the ungrounded configuration, the following must be taken into account:
You must provide a main switch (1) according to VDE 0100 for the
ET 200C modules, the sensors and the actuators.
You need a fuse (2) for the mains connection of the load power supply
unit.
Use a Siemens load power supply unit of the 6EV1 series (see Catalog
ET 1) for power supply and load voltage supply.
If you use any other load power supply (24 V DC), note that the voltage
must be in the range of 20 V DC to 30 V DC (including ripple). The load
power supply must generate a functional extra-low voltage with
protective separation in accordance with VDE 0106, Part 101. If you use
a switched-mode power supply, you will need a back-up capacitor (with a
rating of 200
F per 1 A load current) (3).
You need a main power fuse to protect the supply voltage (5).
For both grounded and ungrounded configurations, use a low-resistance
conductor to connect the protective ground (PE) terminal of the ET 200C
modules (digital modules, power supply connector, programmer
connector) to the protective ground conductor or the chassis ground
(mache ground) (6).
The right-hand side of the power supply connector features a screw for
connecting the protective ground conductor. PE is looped in via the power
supply connector.
In addition, the protective ground conductor must be connected to the PE
pin in the 12-pin round connector or 6-pin round connector. PE pin and
housing are linked internally.
You must provide insulation monitoring to ground with voltage clamping
(7).
!
Warning
The ungrounded configuration can be neutralized by grounded machine parts
and grounded electrical devices.
Example: A grounded sensor or actuator links the PE protective ground to
the M potential of the control system.
Definition
Rules
Mechanical and Electrical Installation
Summary of Contents for SIMATIC ET 200C
Page 18: ...xviii ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Contents ...
Page 26: ...1 8 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Configuration ...
Page 44: ...2 18 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b ET 200C Configuration Options ...
Page 68: ...3 24 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b ET 200C Components ...
Page 202: ...10 4 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b General Technical Specifications ...
Page 226: ...11 24 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Digital Modules ...
Page 270: ...12 44 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Analog Modules ...
Page 280: ...13 10 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Other ET 200C Components ...
Page 310: ...C 4 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Safety Related Guidelines ...
Page 318: ...Glossary 8 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Glossary ...
Page 324: ...Index 6 ET 200C Distributed I O Station EWA 4NEB 812 6119 02b Index ...