Juniper EX9214 Hardware Manual page 142

• For switches with DC power supplies, allow at least 24 in. (61 cm) of clearance in front of the switch
and at least 29.05 in. (73.8 cm) of clearance behind the switch. Allow 2.8 in. (7.1 cm) between the
side of the chassis and any non-heat-producing surface such as a wall. See
Figure 42: Clearance Requirements for Airflow and Hardware Maintenance for an EX9214 Switch
with DC Power Supplies
• If you are mounting the switch on a rack or cabinet along with other equipment, ensure that the
exhaust from other equipment does not blow into the intake vents of the chassis.
Airflow must always be from front to back with respect to the rack. If the device has side to rear
airflow, then provisions must be made to ensure that fresh air from the front of the rack is supplied
to the inlets, and the exhaust exits at the rear of the rack. The device must not interfere with the
cooling of other systems in the rack. Fillers must be used as appropriate in the rack to ensure there is
no recirculation of heated exhaust air back to the front of the rack. You must also ensure that hot air
does not flow around the cables.
• For service personnel to remove and install hardware components, there must be adequate space at
the front and back of the switch. At least 24 in. (61 cm) is required both in front of and behind the
switch. NEBS GR-63 recommends that you allow at least 30 in. (72.6 cm) in front of the rack and
24 in. (61.0 cm) behind the rack.
Figure 42 on page 131.
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