Siemens SIMATIC HMI TP 070, Equipment Manual

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TP 070 Equipment Manual
Release 03/00
ESD Guidelines
What does ESD mean?
Virtually all present-day modules incorporate highly integrated MOS devices or
components. For technological reasons, these electronic components are very
sensitive to overvoltages and consequently therefore to electrostatic discharge:
These devices are referred to in German as Elektrostatisch Gefährdeten
Bauelemente/ Baugruppen: ”EGB”
The more frequent international name is:
”ESD” (Electrostatic Sensitive Device)
The following symbol on plates on cabinets, mounting racks or packages draws
attention to the use of electrostatic sensitive devices and thus to the contact
sensitivity of the assemblies concerned:
ESDs may be destroyed by voltages and energies well below the perception
threshold of persons. Voltages of this kind occur as soon as a device or an
assembly is touched by a person who is not electrostatically discharged . Devices
exposed to such overvoltages cannot immediately be detected as defective in the
majority of cases since faulty behavior may occur only after a long period of
operation.
Precautions against electrostatic discharge
Most plastics are capable of carrying high charges and it is therefore imperative
that they be kept away from sensitive components.
When handling electrostatic sensitive devices, make sure that persons, workplaces
and packages are properly grounded.
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