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Intr
oductio
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Chapter 1
Introduction
This chapter describes the the Backup PSU, the PSU Module, and the Collage 740 Backbone ATM
Switch.
About the Backup PSU
The Backup PSU provides the Collage 740 Backbone ATM Switch with increased resilience by
insuring against the possibility of a fault in the internal PSU Module. When you connect a
Backup PSU to a Collage 740, the Backup PSU provides power to the switch’s backplane. The
Collage 740’s internal PSU Module and the PSU Module in the Backup PSU share the power load to
the Collage 740, so that if one power supply fails, the other unit supplies the full power load.
You can connect the Backup PSU to one Collage 740 for each PSU Module that is installed. The
Backup PSU supports a maximum of two PSU Modules, called PSU-01 and PSU-02, which means
you can connect it to a maximum of two Collage 740s.
Note:
The Backup PSU package contains one PSU Module, one mains cable, and one DC power
cable. To connect the Backup PSU to a second Collage 740, you need one additional PSU Module
(part number: 57-77) and one additional cable set (part number: 57-98).
