Telephone Wiring Guidelines; Preventing Electrostatic Discharge Damage - Cisco 7304 Installation And Configuration Manual

Safety Guidelines

Telephone Wiring Guidelines

Use the following guidelines when working with any equipment that is connected to telephone wiring or
to other network cabling:
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Preventing Electrostatic Discharge Damage

Electrostatic discharge (ESD) damage, which can occur when electronic cards or components are
improperly handled, results in complete or intermittent failures. Line cards 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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For safety, periodically check the resistance value of the antistatic strap. The measurement should be
Caution
between 1 and 10 megohms (Mohms).
Cisco 7304 6-Port Clear Channel E3 Line Card Installation and Configuration
2-8
Never install telephone wiring during a lightning storm.
Never install telephone jacks in wet locations unless the jack is specifically designed for wet
locations.
Never touch uninsulated telephone wires or terminals unless the telephone line has been
disconnected at the network interface.
Use caution when installing or modifying telephone lines.
Always use an ESD wrist or ankle strap and ensure that it makes good skin contact.
Connect the equipment end of the strap to an unfinished chassis surface.
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.
When removing a component, use any available ejector levers or captive installation screws to
release the bus connectors from the backplane or midplane.
Handle carriers by available handles or edges only; avoid touching the printed circuit boards or
connectors.
Place a removed board component-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.
Avoid contact between the printed circuit boards and clothing. The wrist strap protects components
from ESD voltages on the body only; ESD voltages on clothing can still cause damage.
Never attempt to remove the printed circuit board from the metal carrier.
Chapter 2 Preparing for Installation
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