Juniper Networks MX240 manual Cabinet Requirements, Cabinet Size and Clearance Requirements

MX240 Ethernet Services Router Hardware Guide

Table 19: Site Preparation Checklist (continued)

Item or Task	For More Information	Performed By	Date
Calculate the optical power budget and optical	“Calculating Power Budget for
power margin.	Fiber-Optic Cable” on page 181

Cabinet Requirements

The router can be installed in a standard 482-mm wide (or larger) enclosed cabinet. The following sections describe cabinet requirements:

■Cabinet Size and Clearance Requirements on page 30

■Cabinet Airflow Requirements on page 30

Cabinet Size and Clearance Requirements

The minimum-sized cabinet that can accommodate the router is 482-mm wide and 800-mm deep. A cabinet larger than the minimum requirement provides better airflow and reduces the chance of overheating. To accommodate a single router, the cabinet must be at least 13 U high. If you provide adequate cooling air and airflow clearance, you can stack several routers in a cabinet that has sufficient usable vertical space. Each router requires 5 U.

The minimum total clearance inside the cabinet is 30.7 in. between the inside of the front door and the inside of the rear door.

Cabinet Airflow Requirements

When you mount the router in a cabinet, you must ensure that ventilation through the cabinet is sufficient to prevent overheating. Consider the following requirements to when planning for chassis cooling:

■Ensure that the cool air supply you provide through the cabinet can adequately dissipate the thermal output of the router.

■Ensure that the cabinet allows the chassis hot exhaust air to exit from the cabinet without recirculating into the router. An open cabinet (without a top or doors) that employs hot air exhaust extraction from the top allows the best airflow through the chassis. If the cabinet contains a top or doors, perforations in these elements assist with removing the hot air exhaust. For an illustration of chassis airflow, see Figure 17 on page 25.

■Install the router as close as possible to the front of the cabinet so that the cable management system just clears the inside of the front door. This maximizes the clearance in the rear of the cabinet for critical airflow.

■Route and dress all cables to minimize the blockage of airflow to and from the chassis.

30■ Cabinet Requirements