Prerequisites
Rack Dimensions and Site Layout
For complete site requirements and recommendations, refer to the Cisco 7000 Hardware Installation and Maintenance or Cisco 7507 Hardware Installation and Maintenance publications. To help maintain
•Place the chassis in a location with sufficient access to power and network interface cables. Avoid straining cables or routing them near traffic paths or power cables (which can cause interference).
•During the installation, allow sufficient working space around the rack. You will need at least three feet in front of the rack to lift the chassis and insert it, and two feet of clearance outside the power supply bays to insert power supplies.
•After installation, allow at least two to three feet of clearance behind the rack for maintenance. Because the interface processor end of the router provides access to the power switches, processor slots, and status LEDs, we recommend that you mount the interface processor end at the most accessible side of the rack. You should be able to access both ends of the router without having to remove it from the rack.
•Some equipment racks provide a power strip along the length of one of the rear mounting strips. If your rack has this feature, consider the position of the strip when planning fastener points and determine whether you will install the chassis from the front or the rear of the rack. Power supplies are installed in the rear of the chassis, and a power strip might partially block access to the bay.
•If your rack is enclosed, or if it has a door on the front, temporarily remove the door to provide enough clearance for installation. If the rack does not provide a rear door for access to the rear chassis panel, install the chassis backwards in the rack so you can access the FRUs and spare parts, and view the LEDs.
Rack Ventilation
Planning a proper location for the router and the layout of your equipment rack is essential for successful system operation. Equipment placed too close together or inadequately ventilated can cause overtemperature conditions inside the chassis. In the chassis, the cooling air is drawn in through the front of the chassis, and the exhaust air is forced out the back between the interface processor faceplates.
The following guidelines are recommended to ensure a sufficient flow of cooling air to the chassis:
•Place the chassis in a location that enables the flow of cooling air through the chassis. The chassis blower draws cooling air in through the front chassis panel, past the internal components, and out the back panel. Inhibiting the intake, blocking the exhaust, or allowing heated air to enter the intake can cause overtemperature conditions and cause the system to shut down.
•Because the intake and exhaust ports for cooling air are located on the front and rear of the chassis, multiple chassis can be stacked with little or no clearance in a rack. You can remove the four feet on the chassis after the chassis is mounted in the rack.
•Install the chassis in an open rack whenever possible. If installation in an enclosed rack is unavoidable, ensure that the rack has adequate ventilation or an exhaust fan.
•Conversely, a ventilation system that is too powerful in a closed rack may also prevent cooling by creating negative pressure around the chassis and redirecting the air away from the chassis intake vent. If necessary, operate the chassis with the rack open.
•Equipment near the bottom of a rack may generate excessive heat that is drawn upward and into the intake ports of equipment above, leading to overtemperature conditions in the chassis at or near the top of the rack.
14Cisco 7000 and Cisco 7507