Typically, power receptacles are placed on the rack with the switch. If the DC power source is further than allowed by
the DC power cables, you can install a power interface unit (PIU) in the rack with the switch and connect that to the
power source with other cabling.
Maximum Distance Between Receptacle and Power Supply
Power Supply
12 feet (3.6 m)
All AC power supplies
14 feet (4.26 m)
HVAC/HVDC 3.5-kW power
supplies
Determined by the length of the power cord that you supply.
DC 3-kW power supplies
Rack and Cabinet Requirements
You can install the following types of racks or cabinets for your switch:
• Standard perforated cabinets
• Solid-walled cabinets with a roof fan tray (bottom to top cooling)
Installation clearance requirements for solid-wall cabinets are not in the scope of
this guide. Such installations have to be custom-engineered by a cooling
professional. The customised configuration should satisfy the requirements
mentioned in the
and the
sections.
Note
• Standard open four-post Telco racks
• Standard open two-post Telco racks
To correctly install the switch in a cabinet that is located in a hot-aisle/cold-aisle environment, you should fit
the cabinet with baffles to prevent exhaust air from recirculating into the chassis air intake.
Work with your cabinet vendors to determine which of their cabinets meet the following requirements or see
the Cisco Technical Assistance Center (TAC) for recommendations:
• Use a standard 19-inch, four-post Electronic Industries Alliance (EIA) cabinet or rack with mounting
rails that conform to English universal hole spacing per section 1 of the ANSI/EIA-310-D-1992 standard.
• The height of the rack or cabinet must accommodate the 9-RU (15.75 inches or 40.0 cm) height of the
switch and its bottom support bracket.
• The depth of a four-post rack must be 24 to 32 inches (61.0 to 81.3 cm) between the front and rear
mounting brackets.
• Required clearances between the chassis and the edges of its rack or the interior of its cabinet are as
follows:
• 7.5 inches (19.1 cm) between the front of the chassis and the front of the rack or interior of the
cabinet (required for cabling).
Cisco Nexus 7706 Hardware Installation Guide
OL-31330-01
10
Preparing the Site
Rack and Cabinet Requirements