Siemens SIMATIC HMI OP37/Pro, Руководство по эксплуатации оборудования

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OP37/Pro Equipment Manual
Release 7/98
ESD Guidelines
Virtually all modern circuit boards are fitted with highly integrated modules or
components using MOS technology. Due to the technology involved, such
electronic components are very sensitive to excess voltages and therefore to
electrostatic discharge.
The common international term for such equipment is
Electrostatically Sensitive Devices
usually abbreviated to ESD.
The symbol illustrated below appears on cabinets, module racks and packaging
to indicate that they contain electrostatically sensitive devices and that there-
fore the appropriate precautions regarding touching those items should be ob-
served.
ESDs can be damaged by voltages and energy levels far below those that we as
humans are capable of perceiving. Such voltages can occur simply by a com-
ponent or module being touched by a person whose electrostatic potential has
not been discharged. Components subjected to such excess voltages do not
normally immediately show obvious signs of damage as malfunction may not
occur until the item concerned has been in operation for a long period.
Most plastics very easily become statically charged and should therefore be
kept well away from sensitive components!
When handling electrostatically sensitive devices, care should be taken to en-
sure that people, working surfaces and packaging are properly earthed!
What does ESD
mean?
Important safety
precautions for
preventing static
charge
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