Juniper QFX3500, Hardware Documentation

Page: 145 / 669

Table 30: Cabinet Requirements and Specifications
Guidelines
Cabinet
Requirement
•
The minimum cabinet size is 36 in. (91.4 cm) depth. Large cabinets improve airflow and
reduce chances of overheating.
Cabinet size
•
The outer edges of the front mounting brackets extend the width of the chassis to 19 in.
(48.2 cm).
•
The minimum total clearance inside the cabinet is 30.7 in. (78 cm) between the inside of
the front door and the inside of the rear door.
Cabinet clearance
When you mount the device in a cabinet, ensure that ventilation through the cabinet is
sufficient to prevent overheating.
•
Ensure adequate cool air supply to dissipate the thermal output of the device or devices.
•
Ensure that the hot air exhaust of the chassis exits the cabinet without recirculating into
the device. An open cabinet (without a top or doors) that employs hot air exhaust extraction
from the top ensures 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.
•
Install the device in the cabinet in a way that maximizes the open space on the side of the
chassis that has the hot air exhaust.
•
Route and dress all cables to minimize the blockage of airflow to and from the chassis.
•
Ensure that the spacing of rails and adjacent cabinets is such that there is proper clearance
around the device and cabinet.
•
A cabinet larger than the minimum required provides better airflow and reduces the chance
of overheating.
Cabinet airflow
requirements
QFX5110 Clearance Requirements for Airflow and Hardware Maintenance
When planning the site for installing a QFX5110, you must allow sufficient clearance around the installed
chassis (see Figure 45 on page 122 ).
121