Siemens Simatic Field PG, Manual

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Guidelines for Handling Electrostatically-Sensitive Devices (ESD)
A-2
SIMATIC Field PG Manual
A5E00075760-04
A.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 vol-
tage values that can still be perceived by human beings. These voltages are pre-
sent if you touch a component or the electrical connections of a module without pre-
viously 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.