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Cisco 7204 Installation and Configuration Guide
OL-5101-02
Chapter2 Preparing for Installation Safety Recommendations
Safety with Electricity
The port adapters and power supplies are designed to be removed and replaced while the system is
operating without presenting an electrical hazard or damage to the system. However, you must power
down the system before removing or replacing the I/O controller and n etwor k pro ce ssing engi ne.
Follow these basic guidelines when working with any electrical equipment:
•Before beginning any procedures requiring access to the chassis interior, locate the emergency
power-off switch for the room in which you are working.
•Disconnect all power and external cables before installing or removing a chassis.
•Do not work alone when potentially hazardous conditions exist.
•Never assume that power has been disconnected from a circuit; always check.
•Do not perform any action that creates a potential hazard to people or makes the equipment unsafe.
•Never install equipment that appears damaged.
•Carefully examine your work area for possible hazards such as m ois t flo ors, u ngroun de d p ower
extension cables, and missing safety grounds.
In addition, use the guidelines that follow when working with any equipment that is disconnected from
a power source, but still connected to telephone wiring or other network cabling.
•Never install telephone wiring during a lightning storm.
•Never install telephone jacks in wet locations unless the jack is specifically des igne d f or w et
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.
Preventing Electrostatic Discharge Damage
Electrostatic discharge (ESD) damage, which occurs when electronic cards or components are
improperly handled, can result in complete or intermittent system failures. The network processing
engine, I/O controller, and each port adapter consists of a printed circuit board that is fixed in a metal
carrier. Electromagnetic interference (EMI) shielding, connectors, and a handle are inte gral componen ts
of the carrier. Although the carrier helps protect the boards, use an antistatic strap whenever handling
the network processing engine, I/O controller, and port adapters. Handle the carriers by the handle and
the carrier edges only; never touch the boards or connector pin s.
Caution Always tighten the captive installation screws on the network processing engine an d I/O controller. (See
Figure 1-4 and Figure 1-9.) These screws prevent accidental removal, provide proper grounding for t he
system, and help ensure that the bus connectors are properly seated in the midplane.
Following are guidelines for preventing ESD damage:
•Always use an ESD wrist strap or ankle strap and ensure that it makes goo d skin con tac t.
•When handling a removed network processing engine, I/O controller, or port adapter, make sure the
equipment end of your ESD strap is attached to an unfinished chassis surface of the router; do not
touch the printed circuit board, and avoid contact between the pr in ted ci rcui t bo ar d and y our