Siemens S7-400 installation manual What is ESD?, Definition

Guidelines for Handling Electrostatically-Sensitive Devices (ESD)

B.1 What is ESD?

Definition:

All electronic modules are equipped with large-scale integrated ICs or components. Due to their design, these electronic elements are very sensitive to overvoltages and thus to any electrostatic discharge.

These Electrostatically-Sensitive Devices are commonly referred to by the abbreviation ESD.

Electrostatically-sensitive devices are labeled with the following symbol:

!Caution

Electrostatically-sensitive devices are subject to voltages that are far below the voltage values that can still be perceived by human beings. These voltages are present if you touch a component or the electrical connections of a module without previously being electrostatically discharged. In most cases, the damage caused by an overvoltage is not immediately noticeable and results in total damage only after a prolonged period of operation.

B-2	Automation System S7-400	Hardware and Installation
		A5E00850741-01