Juniper QFX5240 - Page 52

Table 15 on page 45 provides the rack requirements and specicaons for the QFX5240.
Table 15: Rack Requirements for the QFX5240
Rack Requirement Guidelines
Rack type Use a four-post rack that provides bracket holes or hole paerns spaced at 1-U (1.75 in. or
4.45 cm) increments and that meets the size and strength requirements to support the
weight.
A U is the standard rack unit dened in Cabinets, Racks, Panels, and Associated Equipment
(document number EIA-310–D) published by the Electronics Industry Associaon.
Mounng bracket
hole spacing
The holes in the mounng brackets are spaced at 1-U (1.75 in. or 4.45 cm) increments, so
that the switch can be mounted in any four-post rack that provides holes spaced at that
distance.
Rack size and
strength
• Ensure that the rack complies with the standards for a 19-in. rack as dened in Cabinets,
Racks, Panels, and Associated Equipment (document number EIA-310–D) published by
the Electronics Industry Associaon.
• A 900-mm rack as dened in the four-part Equipment Engineering (EE); European
telecommunicaons standard for equipment pracce (document numbers ETS 300
119-1 through 119-4) published by the European Telecommunicaons Standards
Instute.
The horizontal spacing between the rails in a rack that complies with this standard is
usually wider than the device's mounng brackets, which measure 19 in. (48.26 cm)
from outer edge to outer edge. Use approved wing devices to narrow the opening
between the rails as required.
•
Ensure that the rack rails are spaced widely enough to accommodate the external
dimensions of the switch chassis. The outer edges of the front-mounng brackets
extend the width to 19 in. (48.26 cm).
•
For four-post installaons, the front and rear rack rails must be spaced between 25.6 in.
(65 cm) and 31.5 in. (80 cm) front to back.
• The rack must be strong enough to support the weight of the switch.
• Ensure that the spacing of rails and adjacent racks allows for proper clearance around
the switch and rack.
45