Humidity; Altitude - Cisco Line Card 4500 E-Series Installation Manual

Chapter 2 Preparing for Installation
Figure 2-1
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Humidity

High-humidity conditions can cause moisture migration and penetration into the system. This moisture
can cause corrosion of internal components and degradation of properties such as electrical resistance,
thermal conductivity, physical strength, and size. Extreme moisture buildup inside the system can result
in electrical shorts, which can cause serious damage to the system. Each system is rated to operate at 8
to 80 percent relative humidity, with a humidity gradation of 10 percent per hour. In storage, a system
can withstand from 5 to 95 percent relative humidity. Buildings in which climate is controlled by
air-conditioning in the warmer months and by heat during the colder months usually maintain an
acceptable level of humidity for system equipment. However, if a system is located in an unusually
humid location, a dehumidifier can be used to maintain the humidity within an acceptable range.

Altitude

Operating a system at high altitude (low pressure) reduces the efficiency of forced and convection
cooling and can result in electrical problems related to arcing and corona effects. This condition can also
cause sealed components with internal pressure, such as electrolytic capacitors, to fail or perform at
reduced efficiency. Each system is rated to operate at altitudes from –50 to 6500 feet (–16 to
1981 meters) and can be stored at altitudes of –50 to 35,000 feet (–16 to 10,668 meters).
OL-13972-02
Catalyst 4500 E-Series Airflow (Catalyst 4506-E Chassis Shown)
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Fan assembly
Catalyst 4500 E-Series Switches Installation Guide
Site Requirements
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