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Cisco MGX 8800/8900 Series Hardware Installation Guide
Releases 2 - 5.2, Part Number OL-4545-01, Rev. H0, May 2006
Chapter5 Installing the Cisco MGX Switch or Gateway
Installing the MGX 8850 (PXM1E/PXM45) Switch, MGX 8850/B or MGX 8880 Media Gateway
Note If you are installing the exhaust plenum in a 19-inch cabinet, it i s front-mounted in the rack with
support from rear brackets.
Step2 Position the exhaust, which occupies 3 RUs of space, directly above the upper fan tray.
Step3 Use four mounting screws and a Phillips-head screwdriver to bolt the exhaust plenum in the rack. See
Figure 5-5 for the correct placement of the exhaust plenum.
Step4 If you are installing the exhaust plenum in a 19-inch cabinet, attach the rear-mounting brackets to the
rack, and use screws to secure the fan tray to the rear-mounting brackets.
Install the DC PEM(s)
Warning
Before performing any of the following procedures, ensure that power is removed from the DC
circuits. To ensure that all power is removed, locate the circuit breakers or fuses on the DC power
lines that service the DC circuits. Turn OFF the DC power line circuit breakers and remove the DC
power line fuses.
Statement 322
Warning
Before working on a system that has an On/Off switch, turn OFF the power and unplug the power cord.
Statement 1
Warning
Never install an AC power module and a DC power module in the same chassis.
Statement 264
Warning
Before working on a chassis or working near power supplies, unplug the power cord on AC units;
disconnect the power at the circuit breaker on DC units.
Statement 12
For a DC-powered system, install the DC PEMs at the back of the air intake plenum. Tighten the captive
screws to attach the DC PEM to the component.
If you install only one DC PEM, install it on the right, as viewed from the rear of the air intake plenum.
(See Figure 5-15 for MGX 8850 and Figure 5-16 for MGX 8880.)
Figure5-15 DC PEMs Installed Behind the Air Intake Plenum on MGX 8850
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Primary
DC PEM
Secondary
DC PEM