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Primary and Secondary Power Distribution Units (PDUs)

IP.com Disclosure Number: IPCOM000011814D
Original Publication Date: 2003-Mar-18
Included in the Prior Art Database: 2003-Mar-18
Document File: 4 page(s) / 104K

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Primary and Secondary Power Distribution Units (PDUs)

   The invention is a primary and secondary power distribution unit (PDU) for the IBM* Server Group Enterprise family of racks. The limitations of the existing pSeries* rack power distribution bus (Figure 1) are solved by the PDU tandem as follows:

- availability of up to 10 Amps per IEC 320-C13 outlet as required by some pSeries servers. - availability of IEC 320-C19 outlets for larger amperage rack-mount drawers. - allows quantity 42 1U drawers in a rack with only two line cords. - compliant with the latest safety agency and electrical code requirements.

Figure 1. Power Distribution Bus (PDB)

The core idea of the invention is to provide more power capacity and receptacles from one customer utility feed. The advantages of the primary and secondary PDUs are described.

     First, the rating per IEC 320-C13 outlet increases from 8 Amps in the PDB (Figure 1) to 10 Amps in the PDUs (Figure 2 and Figure 3). The additional two amps are vital to support some pSeries servers.

Second, the primary PDU can support "high-power" rack-mount drawers that


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require more than 10 Amps via the IEC 320-C19 receptacles. If the IEC 320-C19 receptacles are not used to supply the "high-power" rack-mount drawers, the IEC 320-C19 receptacles may be used to supply input power to the IEC 320-C20 inlets of the secondary PDUs.

     Third, the number of IEC 320-C13 receptacles are maximized to support the "worst case" rack configuration, 42 1U drawers. Figure 4 shows the tallest 19" rack IBM offers with 42U of rack-mount space ( 1U = 1.75"). This rack, which is part of the IBM Enterprise family of racks, has four side-pockets typically used for installation of power distribution modules. It is not possible to supply 42 1U drawers with the PDB because only 24 receptacles are available with four PDBs mounted in the side-pockets. However, with two primary PDUs and two secondary PDUs, 42 receptacles are available. Because of the space necessary to support the large quantity of receptacles, the circuit breakers are located on the back side (not visible when installed in a rack side pocket) of the primary and secondary PDUs. Lights are located on the front on the PDUs to indicate the status of the input power and the st...