Rack-Mounting The Plenum Or Spacer; Mounting The Electrostatic Wrist Strap; Figure 7-5 Keyhole Style Bracket - Cisco MGX 8220 Installation And Configuration Manual

Chapter
Figure 7-5
Disposable
alignment

Rack-Mounting the Plenum or Spacer

Either the plenum chamber or the spacer unit (not both) should be mounted immediately above the shelf.
The decision of which one to use is dependent upon the configuration of equipment in the rack and how
the air is to be expelled. The plenum delivers air to the rear of the rack and is used in normal UL
compliant installations where the top of the unit must be covered. The spacer can be used for
installations that have equipment mounted above the MGX 8220 assembly that acts as the necessary top
cover. The spacer guarantees the minimum necessary air exhaust space of 1.75 inches, providing the
sides and rear are open and unobstructed. The MGX 8220 shelf might not be UL compliant when the
spacer is used. Further, the plenum supports the attachment of a cable management kit but the spacer
does not. This is an important factor if cable management is to be used for the upper shelf in two shelf
and four shelf configurations.
Insert the selected unit immediately above the shelf and secure the unit to the shelf with four, number
10-32 machine screws and flat washers.

Mounting the Electrostatic Wrist Strap

The MGX 8220 shelf is provided with a wrist strap that grounds the user and protects the electronic
components from electrostatic shock. The wrist strap kit consists of a strap, a coiled cord, and a clip for
holding the strap. (See Figure 7-6.)
It is recommended that the wrist strap be installed on the left front flange of one of the units at a
convenient height. Use the front mounting screw to secure the ring lug to the flange and front rail. The
other end of the cord is attached to the strap with a snap connector. Peel the back off the clip to expose
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Keyhole Style Bracket
screw
Front
chassis
Disposable
alignment
screw
Bracket
Keyhole-style
holes
Cisco MGX 8220 Installation and Configuration
Rack-Mounting the MGX 8220 Units
Rear
chassis
Spacer
7-11