Juniper QFX5220, Руководство по оборудованию, Страница: 86 / 247

Table 29: Rack Requirements for the QFX5220
Guidelines Rack Requirement
Use a four-post rack that provides bracket holes or hole patterns 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 defined in Cabinets, Racks, Panels, and Associated Equipment
(document number EIA-310–D) published by the Electronics Industry Association.
Rack type
The holes in the mounting brackets are spaced at 1-U (1.75 in. or 4.45 cm) increments, so that
the switch can be mounted in any rack that provides holes spaced at that distance.
Mounting bracket
hole spacing
•
Ensure that the rack complies with the standards for a 19-in. or 23-in. rack as defined in
Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310–D) published
by the Electronics Industry Association.
•
A 600-mm rack as defined in the four-part Equipment Engineering (EE); European
telecommunications standard for equipment practice (document numbers ETS 300 119-1
through 119-4) published by the European Telecommunications Standards Institute
( http://www.etsi.org">href="http://www.etsi.org">http://www.etsi.org http://www.etsi.org">).
The horizontal spacing between the rails in a rack that complies with this standard is usually
wider than the device's mounting 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 switch chassis’
external dimensions. The outer edges of the front-mounting brackets extend the width to
19 in. (48.26 cm).
•
For four-post installations, the front and rear rack rails must be spaced between 23.6 in. (60
cm) and 36 in. (91.4 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.
Rack size and
strength
•
Secure the rack to the building structure.
•
If earthquakes are a possibility in your geographical area, secure the rack to the floor.
•
Secure the rack to the ceiling brackets as well as wall or floor brackets for maximum stability.
Rack connection to
building structure
QFX5220 Cabinet Requirements
You can mount the QFX5220 in an enclosure or cabinet that contains a four-post 19-in. open rack as
defined in Cabinets, Racks, Panels, and Associated Equipment (document number EIA-310-D) published by
the Electronics Industry Association.
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