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S7-300 Automation System, Hardware and Installation: CPU 31xC and CPU 31x
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This section contains information about the overall configuration of an S7-300 on a
grounded incoming supply (TN-S network):
• Circuit-breaking devices, short-circuit and overload protection to VDE 0100 and
VDE 0113
• Load power supplies and load circuits
• Grounding concept
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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.
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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.