General Protective Measures Against Electrostatic Discharge Damage - Siemens simatic c7-621 Hardware Installation Manual

Guidelines for Handling Electrostatically Sensitive Devices (ESD)
B.3 General Protective Measures Against Electrostatic Discharge
Damage
Keep Plastics
Keep plastics away from sensitive devices. Most plastic materials have a
away
tendency to build up electrostatic charges easily.
Provide Sufficient Make sure that the personnel, working surfaces and packaging are
Grounding sufficiently grounded when handling electrostatically sensitive devices.
Avoid any Contact
If possible, avoid any contact with electrostatic sensitive devices. Hold
modules without touching the pins of components or printed conductors. In
this way, the discharged energy cannot affect the sensitive devices.
Additional Note the following measures that have to be taken for modules that are not
Precautions for protected against accidental contact:
Modules without
Housings
B-4
Touch electrostatic sensitive devices only
– if you wear a wristband complying with ESD specifications or
– if you use special ESD footwear or ground straps when walking on an
ESD floor.
Persons working on electronic devices should first discharge their bodies
by touching grounded metallic parts (e.g. bare metal parts of switchgear
cabinets, water pipes, etc.).
Protect the modules against contact with chargeable and highly insulating
materials, such as plastic foils, insulating table tops or clothes made of
artificial fibers.
Place electrostatic sensitive devices only on conductive surfaces:
– Tables with ESD surface
– Conductive ESD foam plastic (ESD foam plastic is mostly colored
black)
– ESD bags
Avoid direct contact of electrostatic sensitive devices with visual display
units, monitors or TV sets (minimum distance to screen > 10 cm).
C7-621 / C7-621 AS-i Control Systems
C79000-G7076-C621-01