User's Manual

3-3
Cisco Catalyst 490 0M Switch Ins talla tion Guid e
78-18350-02
Chapter 3 Installing the Switch
Rack-Mounting the Switch
– The rack must have sufficient vertical clearance to insert the chassis. The chassis height is 2 U
(3.5 inches (8.9 cm)).
• The equipment rack is stable and in no danger of falling over.
– Ensure that the shelf is constructed to support the weight and dimensions of the chassis. For
physical specificatio ns, see A ppendix A, “Specifications.”
– We recommend that you bolt the rack to the floor.
– Mount the unit at the bottom of the rack if it is the only unit in the rack.
– Install heavier equipment in the lower half of the rack to maintain a low center of gravity and
prevent the rack from becoming top-heavy and tipping over.
– Install the stabilizers before mounting or servicing the switch in the rack (if the rack is provided
with stabilizing devices).
• The equipment rack is properly ventilated.
– Install the chassis in an enclosed rack only if it has adequate ventilation or an exhaust fan; use
an open rac k when ever p ossi ble .
– Ensure that the ambient temperature of the rack environment does not exceed a maximum
temperat ure o f 10 4°F ( 40°C). Note that if the switch is installed in a closed or multiunit rack
assembly, the ambient operating temperature of the rack environment might be higher than the
ambient room temperature.
– Note that a ventilation system in a closed rack that is too powerful might also prevent cooling
by creating negative pressure around the chassis and redirect ing the air away from the chas sis
intake vent. If necessary, operate the chassis with the rack open.
– To prevent airflow restriction, allow at least 3 inches ( 7.6 cm) of clearance ar ound the
ventilation openings on the sides of the chassis.
– Use baffles correctly to assist in cooling the chassis.
– Note that equipment near the bottom of a rack may generate excessive heat that is drawn upward
and into the intake ports of equipment a bove, leading to overtemper ature conditions i n the
chassis a t or ne ar the t op of t he rack .
– Consider the equipment and cabling that is already installed in the rack. Ensure that cables from
other equipment will not obstruct the airflow through the chassis or impair access to the power
supplies or switching modules. Route cable s away from field-replacea ble components to avoid
disconnecting cables unneces sarily for equipment m aintenance or upgrad es.
– Allow at least 3 to 4 feet (91.4 to 121.9 cm) of clearance behind the rack for maintenance and
removal of switch assemblies. If the rack is mobile, you can push it back within 1 foot (30.45
cm) of a wall or cabinet for normal operation and pull it out when necessary for maintenance.
Lifting the Chass is Safely
The chassis is not intended to be moved frequently. Before you install the switch, ensure that your site
is properly prepared so that you can avoid moving the chassis later to accommoda te power sources and
network connections.
Whenever you lift a chassis or any heavy object , follow these guidelin es:
• Ensure that your footing is solid, and balance the weight of the cha ssis between your fee t.
• Lift the chassis slowly; never move suddenly or twist your body as you lift.