Air Flow - Cisco 6509 - Catalyst Chassis Switch Installation Manual

Site Requirements

Air Flow

The system fan assembly provides cooling air for the supervisor engine and the switching modules.
Table 2-2
trays.
switches. Sensors on the supervisor engine monitor the internal air temperatures. If the air temperature
exceeds a preset threshold, the environmental monitor displays warning messages.
The Catalyst 6500 series switch is designed to be installed in an environment where there is a sufficient
volume of air available to cool the supervisor engines, modules, and power supplies. Any constraints
placed on the free flow of air through the chassis or an elevated ambient air temperature can cause the
switch to overheat and shut down.
To maintain proper air circulation through the Catalyst 6500 switch chassis, we recommend that you
maintain a minimum 6-inch (15 cm) separation between a wall and the chassis air intake or a wall and
the chassis hot air exhaust. In situations where the switch chassis are installed in adjacent racks, you
should allow a minimum of 12-inches (30.5 cm) between the air intake of one chassis and the hot air
exhaust of another chassis. Failure to maintain adequate spacing between chassis can cause the switch
chassis that is drawing in the hot air exhaust to overheat and fail. On Catalyst 6500 series chassis in
which the airflow is from front to back, the chassis may be placed side-to-side.
If you choose to install your Catalyst 6500 series switch in an enclosed or partially enclosed rack, we
strongly recommend that you verify that your site meets the following guidelines:
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Note
Catalyst 6500 Series Switches Installation Guide
2-10
lists the Catalyst 6500 series switch chassis along with the supported and unsupported fan
Table 2-3 lists the chassis air flow architecture and requirements for the Catalyst 6500 series
Verify that there is a minimum of 6 inches (15 cm) of clearance between the sides of the rack and
both the chassis air intake grill and the chassis air exhaust grill.
Verify that the ambient air temperature within the enclosed or partially enclosed rack is within the
chassis operating temperature limits. After installing the chassis in the rack, power up the chassis
and allow the chassis temperature to stabilize (approximately 2 hours). Measure the ambient air
temperature at the chassis air intake grill and at the chassis air exhaust grill by positioning an
external temperature probe approximately 1 inch (2.5 cm) away from the grills, in line with the
chassis slot occupied by the supervisor engine.
– If the ambient intake air temperature is less than 40°C (104°F), the rack meets the intake air
temperature criterion.
– If the ambient intake air temperature exceeds 40°C (104°F), the system might experience minor
temperature alarms and is in danger of overheating.
– If the ambient intake air temperature equals or is greater than 55°C (131°F), the system will
experience a major temperature alarm and shut down.
Verify that the enclosed or partially enclosed rack allows an adequate flow of air through the switch
chassis as follows:
– If the difference between the measured intake air temperature and the exhaust air temperature
does not exceed 10°C, there is sufficient airflow in the rack.
If the difference in air temperature exceeds 10° C, there is insufficient airflow to cool the
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chassis.
The 10°C temperature differential between the intake and the exhaust must be determined by
taking measurements using external digital temperature probes. Do not use the chassis internal
temperature sensors to measure the temperature differential.
Chapter 2 Preparing for Installation
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