Siemens S7-400 installation manual Lightning Protection and Overvoltage Protection, Overview

Assembling and Installing Systems

A.9 Lightning Protection and Overvoltage Protection

Overview

Failures are very often the result of overvoltages caused by:

•Atmospheric discharge or

•Electrostatic discharge.

First of all, we want to introduce you to the lightning protection zone concept, on which the protection against overvoltage is based.

At the end of this section, you will find rules for the transitions between the individual lightning protection zones.

Note

This section can only provide information on the protection of a programmable logic controller against overvoltages.

However, a complete protection against overvoltage is guaranteed only if the whole surrounding building is designed to provide protection against overvoltages. This refers especially to constructional measures for the building already in the planning phase.

If you wish to obtain detailed information on overvoltage protection, we therefore recommend you to address your Siemens contact or a company specialized in lightning protection.

A-20	Automation System S7-400	Hardware and Installation
		A5E00850741-01