Chapter 2
Preparing for Installation
Preventing Electrostatic Discharge Damage
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Sometimes, voltage is discharged to some of the pins of the connector and not
others, or to some pins on the connector before others. This is known as a
differential discharge event, which can damage the networking equipment being
connected.
You can take the following measures to prevent ESD cable damage:
Ground the cable before connecting the networking equipment. You can
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create a grounding cable using an RJ-45 patch cable by doing the following:
Bare the wires on one end
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Connect the wires to a suitable and safe earth ground
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Connect the RJ-45 cable to a female RJ-45 connector
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Briefly connect all cables to the grounded cable before connecting to
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networking equipment.
Leave cables from the networking equipment in the distribution closet
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connected to ports at user desktops. After you make connections on either
side of the cable to networking equipment, the cable will not build up charge.
Electrostatic discharge (ESD) damage, which can occur when electronic cards or
components are improperly handled, results 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:
Always use an ESD wrist or ankle strap and ensure that it makes good skin
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contact.
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Connect the equipment end of the strap to an unfinished chassis surface.
When installing a component, use any available ejector levers or captive
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installation screws toproperly seat the bus connectors in the backplane or
midplane. These devices prevent accidentalremoval, provide proper
grounding for the system, and help to ensure that bus connectors areproperly
seated.
Catalyst 4500 Series Switches Installation Guide
Electrostatic Discharge
2-3