Modular power distribution unit, module for the power distribution unit, and method of using the same

[0001] Priority is hereby claimed under 35 U.S.C. § 119(e) to commonly owned and U.S. Provisional Patent Application No. 60/333,794 which was filed on Nov. 28, 2001.

[0002] The present application is directed to a modular power distribution unit and method of use and, in particular, to a hot-swappable modular distribution unit and method of use.

[0003] Many types of power distribution units (PDUs) are available for distributing power to components in environments such as, for example, data centers, computer rooms, and communication centers. Presently available PDU systems typically include a box with fixed devices. Commercially available PDUs typically have fixed plug receptacles and breakers, the selection of which is very limited. Frequently, the available PDUs may not include a sufficient variety of receptacles for the different equipment that are used in such environments. When that is the case, users must order additional PDUs to accommodate the user's particular needs. Therefore, when faced with a variety of receptacle needs, a user must frequently select many different PDUs in order to meet the plug receptacle needs for each component requiring power. Thus, the limited configurations of plug receptacles in presently available PDUs increases the expense to the user and increases the amount of space used. This can create many redundant or unuseable plug receptacles that will go unused, and that the user otherwise would not order.

[0004] In addition, presently available PDUs must be hard-wired into the existing system, which, of course, requires the expertise of an electrician. There are many disadvantages to requiring an electrician to hard-wire each additional individual PDU. The PDU cannot be installed immediately, because the services of an electrician must be scheduled. Power to the existing PDUs must be shut off in order to allow the electrician to perform the connection to the new additional PDU(s). When power to the PDU system is shut down, equipment to which power is supplied by the PDUs must be shut off as well, if an alternate source of power is not available. In addition, when equipment is shut off, or is not powered redundantly, workers and systems are no longer productive.

[0005] A solution to the problems of prior power distribution units is provided in the present disclosure, which provides electrical power to equipment in environments such as data centers, computer rooms, or communications centers. The present disclosure recognizes that in these and other environments, the power requirements for the various equipment are multiple and varied, and subject to change. In a computer room, for example, the addition of a computer server, several PC's, or associated peripherals such as printers will require that the electric power be upgraded to accommodate the new equipment. Various electrical receptacles of certain configurations and power ratings must be supplied or the new equipment cannot operate. Also, in an environment such as a computer room, it is desirable for the new power requirements to be fulfilled and changes and upgrades be made without interrupting the power to the existing equipment, which may be involved in critical operations.

[0006] The power distribution unit of the present disclosure allows the electric power to be effectively changed or upgraded to accommodate the new power requirements without interrupting power to existing attached systems or without incurring significant increased cost or inconvenience for users.

[0007] The power distribution unit includes a frame and one or more user-replaceable power modules, which fit into slots in the frame. Each power module provides one or more plug receptacles for attaching equipment to provide power thereto. The power modules are available in a variety of receptacle types, receptacle numbers, and power rating configurations to accommodate various equipment in a particular environment, as needed.

[0008] The frame includes an internal connector panel for distributing power from a power source to the power modules when they are inserted in the frame. The internal connector panel is also a dividing wall, which separates the frame into a region for accommodating power modules and a region for receiving power from a power source and routing the power to the connectors on the connector panel.

[0009] In another aspect of the present disclosure, the power modules have the capability to be “hot-swapped,” where existing modules may be removed and replaced without shutting down any other modules or without the shutting down the electric power to the power distribution unit itself.

[0010] In an alternative embodiment, the power distribution unit includes a remote control capability to provide control of individual control of the power modules from telephone, cable, or DSL lines. In this embodiment, the power distribution unit includes a remote control unit and circuitry, which allows the power distribution unit to receive and respond to control signals from a distance to implement functions such as sequencing the start-up or shut-down of individual power modules, timed start-up and shut-down, or direct user control as desired. Alternatively, the individual power modules may be controlled by a stored computer program.

[0011] In still another alternative embodiment, the concepts of the present invention may be incorporated into entertainment products such as VCRs and DVDs to facilitate adapting these devices for countries having different electrical source voltages, frequencies, and plug types. In this embodiment, the entertainment product accepts into a slot a power module adapted for receiving and converting power from a country's domestic electric power system for use in powering the product. The power module includes a receptacle for the country of use.

[0012] These and other features of the present disclosure will be understood from the description to follow, taken in conjunction with the accompanying drawings.

[0023] The power distribution unit 10 of the present disclosure allows users to select configurations of plugs and receptacles to be compatible with the user's specific needs. The system has a frame and module construction that is scalable and customizable, as will be described.

[0024] A preferred embodiment of the a power distribution unit 10 according to the present disclosure is illustrated initially with reference to FIGS. 1 and 2, taken together, which show a front perspective view of the present disclosure. The power distribution unit 10 incorporates a frame 12 in the form of a box-shaped housing. The frame 12 includes a first support member 14, side panels 16 and 18, top panel 20, front panel 22 and rear panel 24. The frame 12 and its components are preferably fabricated from sheet steel to provide rigidity and durability, although other materials, may be contemplated. In use, the frame 12 may be mounted in an equipment rack or be floor mounted, depending on the size of the frame 12 and the user's needs.

[0025] The power distribution unit 10 includes at least one power module 26 and is generally configured to accommodate several power modules 28, 30, 32, as shown in FIGS. 1 and 2. Although four power modules are shown, it can be seen that additional slots are provided for two more power modules in the preferred embodiment. The front-facing side of the frame 12 is basically open and provides means for accepting and mounting therein one or more power modules.

[0026] The first support member 14 is a welded structure having upper and lower surfaces to provide a rigid base for supporting all the components of the power distribution unit 10. The frame 12 includes a dividing wall 34 mounted on the first support member 14. The dividing wall includes first and second opposing surfaces. The dividing wall 34 divides the frame 12 into first and second sections in which various components of the power distribution unit 10 are positioned. The dividing wall 34 includes a plurality of apertures (not illustrated) in which a corresponding number of electrical connectors 36–46 may be supported, as shown in FIGS. 2, 4 and 6. When inserted into the apertures, a portion of each of the electrical connectors 36–46 extends through the dividing wall 34 into the first section and into the second section. The electrical connectors 36–46 are preferably rigidly attached to the dividing wall 34 by, for example, friction fitting, gluing, or with fasteners such as screws, rivets, and the like, as shown in the present embodiment.

[0027] A power cable 48 provides a source of electrical power to the power distribution unit 10 and to the connectors 36–46 from a coupled power supply (not shown). The power provided over power cable 48 by the power supply should be sufficient to drive a fully loaded power distribution unit 10, that is, where power distribution modules occupy each slot. The electrical connections and cabling will be explained in more detail further on. Those of ordinary skill in the art will recognize that any other means or method of connecting power to power distribution 10 may be used, and that the system is not limited to a direct connection.

[0028] Power modules will now be explained in connection with FIGS. 2 and 3. Power modules function basically to receive electrical power from the power distribution unit 10 through an attached connector and to route the power though a switched device such as a circuit breaker to receptacles mounted on the front bezel of the power module. Power modules 26–32 slide into the frame 12 in predefined slot positions, so that, in its fully inserted position, the connector on the power module 26 couples with one of the connectors 36–46 supported on the dividing wall 34. The frame 12 includes upper and lower card guides 50–60 for linearly guiding a power module 26 into any of the six slots that correspond to the connectors 36–46 mounting on the dividing wall 34. It is also contemplated that card guides 50–60 may include grounding channels to provide a ground connection to the power module 26 when it is inserted into the frame 12, as shown in the present embodiment. Alternatively, the grounding channels may be eliminated by including in each male connector a grounding pin (i.e. longer than other pins in the male connector), which also will provide a ground connection to the power module 26.

[0029] Turning to FIG. 3, a typical power module 26 is shown in more detail. The power module 26 includes a bezel 62, perpendicularly mounted on a card 64. The card 64 includes a power connector 66 for coupling with a complementary connector 40 mounted in the dividing wall 34. The bezel 62 includes cutouts for mounting a switched device, such as circuit breaker 68 and one or more power receptacles 70, 72. The card 64 is sized for engaging the corresponding set of upper and lower card guides 60, 54 for the slot into which it is being inserted. Although a circuit breaker is shown herein, it should be understood that any switch capable of controlling the designated current flow may alternatively be used.

[0030] When installed in the frame 12, the power module 26 is held in firm place within the frame 12 by holding screws 74, 76. The holding screws 72,74 have knurled heads, which respond to finger pressure for tightening or loosening. Knurled head screws are well known in the art for holding or clamping removable modular components in electrical cabinets and the like.

[0031] There are various types of power modules each having different power ratings and different receptacles. In environments such as computer rooms, three-phase power receptacles may be required. Power modules are provided with single, duplex, or multiple receptacle configurations. In the preferred embodiment, a wide variety of power module configurations are provided. A catalog of available power modules provides a user with a full range of power receptacle configurations, defined by standards established by various agencies or associations such as NEMA (National Electrical Manufacturers Association), which is conventional in the United States. Other standards that have been established domestically and/or internationally include, for example, CEE, CEE 7-7, BS, AS/NZS, CEI, SEV, SI, AFSNTI, EDP, JIS, IEC320, and IEC309. The various module configurations may be ordered as needed or an inventory of selected power modules may be stored for ready use, depending on the needs of the user and the particular installation. For example, NEMA receptacle configurations which are usable with the present disclosure include: 5-15R; 5-20R; 6-20R; L5-20R; L5-30R; L6-20R; L6-30R; L14-30R; and L21-30R. In the preferred embodiment, power modules with three-phase receptacles are provided in A, B & C phase configurations to facilitate load balancing requirements.

[0032] The module breaker 68 controls power to the receptacles on the power module 26. The breaker 68 includes a manually-operated switch 77 for powering the module on and off. The module breaker 68 is rated to accommodate the current being delivered to the receptacles 70,72 of each particular power module 26.

[0033] Turning now to FIG. 4, a front view of the power distribution unit 10 is shown, in which it can be readily be seen that power modules having different receptacle types, different receptacle numbers, and different power capabilities can be accommodated or interchanged in the power distribution unit 10. The left-most power module 32 includes a single NEMA L6-20R receptacle 78 and double-pole 20-amp circuit breaker 80. The middle power module 30 includes four NEMA 5-20R power receptacles 82–88 and a single pole 20-amp circuit breaker 90. The right-most power module 28 includes a single NEMA L5-20R receptacle 92 and a single pole 20-amp circuit breaker 94. The receptacles may include locking and non-locking types.

[0034] FIGS. 5 and 6 show the rear section of the power distribution unit 10, with the rear panel 24 removed so that the internal components are visible. The components and wiring contained within the rear section of the power distribution unit 10 are for receiving power from a power source and distributing the power to the electrical connectors 36–46 mounted in the dividing wall 34. The power source may be any mechanism capable of providing direct or alternating current from any generating source.

[0035] The rear section, behind the dividing wall 34, includes a terminal block 96 and a grounding block 98. In the preferred embodiment, a main breaker 100 is also provided to be electrically coupled between the power source and the terminal block, as shown in the schematic diagram of FIG. 7. The terminal block 96 and grounding block 98 are preferably supported on the first support member 14. The main breaker 100 is preferably mounting on and extends through the rear panel 24 (removed in the figures). The terminal block 96 is adapted to be coupled to a source of power by the power cable 48 and to the grounding block 98. The power cable 48 includes a number of individual conductors that are coupled, through interconnecting wiring, to the main breaker 100 and to the terminal block 96. Alternative means of connection also may be used, if desired or more practical, such as printed circuit board.

[0036] The terminal block 96 has a number of connection points. The purpose of the terminal block 96 is to distribute power to the connectors 36–46 mounted in the dividing wall 34 of the frame 12. Each of the electrical connectors 36–46 mounted in the dividing wall 34 have the same connections to the terminal block and to the ground connection; i.e. the electrical connectors 36–46 are commonly coupled to the grounding block 98 connection and commonly coupled to the terminal block 96. This wiring arrangement can also be seen in FIG. 7.

[0037] In the preferred embodiment, the main breaker 100 mounted on the rear panel 24 is rated at 90 amps, although other variations may be used, such as a 50 amp main breaker. It is also contemplated that the frame 14 may be customized for the particular application, and have a main breaker rating which will be specified by the user. For example, any rating within the range of between 0.10 and 100 amps may be specified. Alternatively, the frame may include a NEMA rated female inlet or a male inlet such as, for example, a NEMA L2130 male inlet, or a direct wiring connection.

[0038] FIG. 7 schematically illustrates the electrical connections of the power distribution unit 10, showing the interconnection wiring for the four power modules 26–32 shown in FIGS. 1 and 2. Electrical power from a power source, received though the power cable 48, is routed through the main breaker 100, which provides overall control of the electric power. The power is then routed to the terminal block 96 and the grounding block 98. From the terminal block 96, the wiring fans out to the connectors 40–46 mounted in the dividing wall 34. Power modules 26–32, installed in the frame 12 of the power distribution unit are automatically coupled to the connectors 40–46 by means of their own connectors, and power is routed to the electrical receptacles of the power modules 26–32.

[0039] To use the power distribution unit 10, a user would first determine the power requirements for some equipment in the particular environment such as a computer room. The user would then choose an appropriate power module 26 to install in an empty slot of the frame 12. Alternatively, if no slots are empty in the frame 12, an unused power module 26 may be removed and the new power module 26 inserted. The new power module 26 would have receptacles 70, 72 to fulfill the specific power requirement for equipment needing power. Often, the altered power requirements may be met by a single power module 26. The module 26 is purchased or taken from stock, for the particular application needed, and simply installed in the frame 14 by turning off the module breaker switch 77, inserting the power module 26 into the frame 12, tightening the two retaining screws 74,76 and then switching the breaker switch 77 on. The installation is completed and the new equipment may then be attached to the receptacles 70, 72 and provided with electrical power.

[0040] It should be appreciated that installation of a power module 26 is accomplished in “hot-swap” mode, without turning off the power to the power distribution unit 10 or without turning off power to any other power module 26. In a similar manner, an old or unused power module 26 may be removed without interrupting power to the power distribution unit 10 simply by switching off its associated breaker switch 77 and removing the power module 26 from its slot.

[0041] Turning now to FIG. 8, an alternative embodiment is shown that provides a remote-control function to the power distribution unit 10. Some equipment, such as a computer CPU, memory units, and peripheral services require that these devices be powered on in a particular sequence to ensure proper operation. In other circumstances, it may be necessary to turn on one computer before another, or to otherwise sequence the startup of computer devices or other equipment attached to the power distribution unit 10. Alternatively, it may be desirable to turn on or turn off the various equipment at a particular clock time, for example.

[0042] The remote-control function is provided by a control unit 102, such as a single-board computer, which receives control signals 104 from an administrator (not shown). The signals may be received in a variety of manners, and may have a corresponding variety of attributes. For example, the single board computer may be a radio receiver, capable of receiving radio signals form a remote device controlled by the administrator some distance away from the control unit 102. Alternatively, the control signals may be analog or digital signals driven by an electrical device accessible to the administrator, and located on the enclosure, for example a keypad or the like. In addition, the control signals could be forwarded from a preprogrammed device that turns on the power supplies in a given predefined pattern. In any of these implementations, upon receipt of the control signals 104 or upon activation of the software-controlled trigger, the relay circuit 106 apparatus will selectively operate to turn on or turn off the selected power module as desired.

[0043] In still another embodiment, the control unit 102 may take the form of a single board computer installed in the frame 12 with an appropriate electrical connector. The control unit 102 would trigger a relay circuit 106 to control power to the individual power modules 26–32. Or the power modules 26–32 themselves may include relay circuits 106 responsive signals received from the control unit 102. In this embodiment, users could remotely communicate with the power distribution unit 10 via telephone, cable, or DSL lines. Once connected the user can remotely and individually control power to each module receptacle.

[0044] Still another alternative embodiment of the enclosure is illustrated in FIG. 9. The concepts of the present disclosure may be incorporated into electronic entertainment products such as VCRs and DVD, so that these devices may be more easily adapted for use in different countries. From country to country, the electric power systems vary in voltage, frequency, and plug type. The United States has a standard of 120 VAC, 60 Hz, with A & B plug types. European countries are converting to a standard of 230 VAC, 50 Hz, but there are still variations in plug types. Other countries differ even more widely from these standards. By using the concepts of the present disclosure, electronic entertainment products or other electric products may either be adapted by the manufacturer for the country of use, or be adapted by a user traveling to another country.

[0045] In FIG. 9, the back panel of a DVD player 108 is shown. The DVD player 108 includes a number of audio plug sockets 110, video plug sockets 112, and a connector 114 for the output of composite video. The DVD player 108 also includes two power module slots 116, 118, for illustrative purposes, although a single slot 116 may be used to implement the concepts of the present disclosure. A power module 120 fits into the slot, so that a connector associated with the power module 120 couples to a connector in the slot. The power module 120 is adapted for receiving power from the electric power of the country of use and for converting that power as necessary for operating the DVD player 108. The power module 120 includes a receptacle 122 for receiving a power cord for attaching the DVD player 108 to a source of electric power. A second slot 118 will accept a second module so that a single DVD player 108 may be configured for use in more than one country. Using the principles of the present disclosure, a manufacturer may provide a universal DVD player or other electric device that could be adapted for use in any country after the insertion of the proper power module 120 in an open slot 116.

[0046] The description of the disclosure has been directed to certain exemplary embodiments. Various modifications of these embodiments, as well as alternative embodiments, will become readily apparent to those skilled in the art. For example, the power distribution unit of the present disclosure is scalable. Although the configurations presented in the preferred embodiments generally are shown to have six slots to accommodate six power modules, it is within the scope of the present disclosure to include a frames of any needed size for accommodating any needed number of power modules, depending of the application. Further, the available power module types may include greater numbers and varieties of power receptacles than illustrated. These and other modifications are certainly within the scope of the present disclosure. Accordingly, the description is to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims rather that by the forgoing description, and all changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.