Electrical Assembly, Protective Measures And Grounding; Grounding Concept And Overall Structure - Siemens SIMATIC S7-300 Hardware And Installation Manual

Configuring
5.8

Electrical assembly, protective measures and grounding

5.8.1 Grounding concept and overall structure

Introduction
This section contains information about the overall structure of an S7-300
connected to a grounded incoming supply (TN-S system). The following aspects
are covered:
• Circuit-breaking devices, short-circuit and overload protection to VDE 0100 and
VDE 0113
• Load power supplies and load circuits
• Grounding concept
An S7-300 can be used in many different ways, so we can only describe the basic
rules for the electrical installation in this document. You must observe at least
these basic rules if you want your S7-300 to operate free of trouble.
Definition: Grounded power supply (PEN)
The neutral is grounded in a grounded power supply system (PEN). A single short-
circuit to ground between a live conductor or a grounded part of the system trips
the protective devices.
Components and protective measures
A number of components and protective measures are prescribed for plant
installations. The type of components and the degree of compulsion pertaining to
the protective measures will depend on the VDE specification applicable to your
particular plant.
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S7-300 Programmable Controller Hardware and Installation
A5E00105492-02