Cisco 4490 - Manual (Page 72)

Chapter 5 Maintaining the Cisco Global Site Selector 4490
Maintaining Your Site Environment
5-4
Cisco Global Site Selector 4490 Hardware Installation Guide
78-15755-02
Dust and Particles
A clean operating environment can greatly reduce the negative effects of dust and
other particles, which act as insulators and interfere with the operation of a
system’s mechanical components. Also, in addition to regular cleaning, you
should follow these guidelines to deter contamination of the system equipment:
• Do not permit smoking anywhere near the system.
• Do not permit food or drink near the system.
• Use dust covers when the system is not in use.
• Close windows and outside doors to keep out airborne particles.
Corrosion
The oil from a person’s fingers or prolonged exposure to high temperature or
humidity can corrode the gold-plated edge connectors and pin connectors on
various devices in the system. This corrosion on system connectors is a gradual
process that can eventually lead to intermittent failures of electrical circuits.
To prevent corrosion, you should avoid touching contacts on boards and cards.
Protecting the system from corrosive elements is especially important in moist
and salty environments, which tend to promote corrosion. Also, as a further
deterrent to corrosion, the system should not be used in extreme temperatures, as
explained in the
“Temperature” section.
Electrostatic Discharge
Electrostatic discharge (ESD) results from the buildup of static electricity on the
human body and certain other objects. This static electricity is often produced by
simple movements such as walking across a carpet. ESD is a discharge of a static
electrical charge that occurs when a person whose body contains such a charge
touches a component in the system. This static discharge can cause components,
especially chips, to fail. ESD is a problem particularly in dry environments where
the relative humidity is below 50 percent.