Siemens SIMATIC Field PG P4, Manual

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Guidelines for Handling Electrostatically-Sensitive Devices (ESD)
A-2
SIMATIC Field PG P4 Manual
A5E00180080-04
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
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.