Nortel Networks 1002rp About the power distribution unit, PDU power and grounding, Multiple PDUs

October 2006 Power supply installation

About the power distribution unit

Introduction

A PDU is installed in a rack that has DC-powered servers. Power from the DC supply source enters the PDU and can then be distributed to one or more servers. A single PDU can supply DC power to four DC power supply modules. A server can have either one or two power supply modules installed. You can determine the number of PDUs to install in a rack by counting the number of power supply modules in each rack.

PDU power and grounding

To ensure a complete power and grounding installation:

„In rackmount DC-powered server installations, ensure the PDU (Power Distribution Unit for DC applications) is installed on the same rack as the CallPilot server. This is required since the main ground wire for the PDU is not insulated from the metal enclosure.

Multiple PDUs

A server operates on a single power supply module. Its total capacity is two installed power supply modules. The second power supply module is the redundant power supply module.

A PDU can distribute power to a maximum of four power supply units that can be installed in two or more servers. Therefore, if there are three or four servers installed in a rack, then you must install a second PDU.

Note: The power supply module installs in the server. It does not refer to a UPS, which is a separate unit on the rack.

1002rp Server Hardware Installation 55