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Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Chapter Connecting Power for AC Systems
Connecting Power for AC Systems
This section describes how to connect AC power to the MGX 8220 shelf.

AC Input Power

The AC power assembly can be configured with either a single primary input AC source, or optional
primary and secondary (redundant) input AC sources. AC power is supplied through connect ors on the
rear panel.

Available Power

The AC power assembly holds up to six independent 875W power supplies, each of which supplies
power to a common output bus. Power is then available for MGX 8220 shelves through connectors on
the rear panel.
The number of power supplies that are configured in the assembly depends upon the number of
MGX 8220 shelves that have to be supported. The maximu m number of MGX 8220 shelves that can be
supported by a single AC power assembly is four.
In a fully loaded configuration each MGX 8220 shelf requires 500W. Therefore, a power assembly
equipped with three power supp lies, totaling 2625W, can supply enough power for a four -shelf rack. A
power assembly equipped with four power supplies, totaling 3500W, provides enough power for a
four-shelf rack even in the event of a single power supply failure. More power supplies provide even
more protection in the event o f m u lt ip le power supply failures.

Monitoring Power Supply Status

In addition to supplying power, each power supply provides a signal that indicates the status of the
power supply.

Rear Panel Connectors

The rear panel has
Primary AC input connector and an optional secondary AC input connector.
Group of four output connector s on the right (looking toward the rear panel), each of which can be
used to connect to an M G X 8 220 shelf. Connectors 1A to 3A provide power an d pow er supply
monitoring. Connector 4A provides power only.
Group of three output connectors on the le ft (looking toward the rear panel), each of which can be
used to connect to an MGX 8220 shelf to provide power supply monitoring.
As shown in Figure7-13, power is available at each of the f our conne cto rs on t he right of th e re ar pa ne l.
A cable from any of these four co nn ect o rs can b e c on n ect ed to an y sh el f in t he ra ck .