Preparing for Installation 2-5
Preventing Electrostatic Discharge Damage
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Never touch uninsulated telephone wires or terminals unless the telephone line has been
disconnected at the network interface.
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Use caution when installing or modifying telephone lines.
Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) damage, which can occur when electronic cards or components are
improperly handled, can result in complete or intermittent failures. Port adapters and processor
modules consist of printed circuit boards that are fixed in metal carriers. Electromagnetic
interference (EMI) shielding and connectors are integral components of the carrier. Although the
metal carrier helps to protect the board from ESD, use a preventive antistatic strap during handling.
Following are guidelines for preventing ESD damage:
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Always use an ESD wrist or ankle strap and ensure that it makes good skin contact.
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Connect the equipment end of the strap to an unfinished chassis surface.
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When installing a component, use any available ejector levers or captive installation screws to
properly seat the bus connectors in the backplane or midplane. These devices prevent accidental
removal, provide proper grounding for the system, and help to ensure that bus connectors are
properly seated.
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When removing a component, use any available ejector levers or captive installation screws to
release the bus connectors from the backplane or midplane.
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Handle carriers by available handles or edges only; avoid touching the printed circuit boards or
connectors.
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Place a removed component board side up on an antistatic surface or in a static shielding
container. If you plan to return the component to the factory, immediately place it in a static
shielding container.
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Avoid contact between the printed circuit boards and clothing. The wrist strap only protects
components from ESD voltages on the body; ESD voltages on clothing can still cause damage.
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Never attempt to remove the printed circuit board from the metal carrier.
Caution
For safety, periodically check the resistance value of the antistatic strap. The measurement
should be between 1 and 10 megohms.
