Siemens SIMATIC HMI OP3, Equipment Manual

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D-2
Operator Panel OP3
Edition 11/99
D.2 Important Precautions against Charge
•
Most plastics are capable of carrying high charges and it is therefore
imperative that they not be placed near sensitive components.
•
When handling electrostatically sensitive devices, make sure people,
workplaces and packaging are properly grounded.
D.3 Handling ESDs
•
A general rule is that modules should be touched only when this cannot
be avoided owing to the work that has to be performed on them. If you
have to touch them, under no circumstances should you handle printed
circuit boards by touching device pins or conductor runs.
•
Devices may be touched only if
– you are grounded by permanently wearing an ESD wrist strap or
– you are wearing ESD shoes or ESD grounding protection strips in
conjunction with an ESD floor.
•
Before you touch an electronic module, your body must be discharged.
The simplest way of doing this is to touch a conductive, grounded object
immediately beforehand – for example, bare metal parts of a control
cabinet, water pipe etc.
•
Modules should not be brought into contact with charge-susceptible and
highly insulating materials, such as plastic films, insulating table tops and
items of clothing containing synthetic fibers.
•
Modules should be deposited only on conductive surfaces (tables with a
ESD coating, conductive ESD cellular material, ESD bags, ESD shipping
containers).
•
Do not place modules near visual display units, monitors or television sets
(minimum distance to screen > 10 cm).
D.4 Measuring and Modifying ESDs
•
Measurements should be made on modules only when
– the measuring instrument is grounded by means of a protective
conductor
or
– the measuring head has been briefly discharged before measurements
are made with a voltages measuring instrument – for example, by
touching a bare metal control cabinet.
•
When soldering, you must use only a grounded soldering iron.
Keep away from
plastics
Grounding
Rules for touching
and environments
Grounding
measuring
instruments/
soldering irons
ESD Guidelines