US20070067119A1 - Rack-mounted power meter having removable metering options module - Google Patents

Abstract

A meter for measuring power parameters on one or more electrical power lines/loads is configured to operate with our without a removable metering options module. The meter includes a meter housing designed and dimensioned for rack mounted installation in a bay of an equipment rack or cabinet, and metering circuitry configured to provide revenue accurate metering and power quality analysis for a power line/load. The metering options module may be mounted to an externally accessible surface of the meter to change the functionality of the metering circuitry without increasing the dimensions of an outer envelop of the meter, and without disturbing tamper-proof seals included on the meter.

Description

RELATED APPLICATIONS
• The present patent document claims the benefit of the filing date under 35 U.S.C. §119(e) of Provisional U.S. Patent Application Ser. No. 60/717,688, filed Sep. 16, 2005, (Attorney Ref. No 6270/172) which is hereby incorporated by reference.
BACKGROUND
• 1. Field of the Invention
• The present invention relates to power metering, and more particularly to a rack-mounted revenue and power quality power meter with an options module that is removable to provide an adaptable modular meter.
• 2. Background and Relevant Art
• Power metering technology is evolving towards multi-functional metering systems. Power meters provide feedback for voltage, current, and power in one or more power lines. The meter also may be configured to provide control functions for a load connected to a power line. Commonly, a meter may be configured for revenue metering, including circuitry and features that allow monitoring of energy usage for the purposes of determining energy costs. Alternatively, a meter may be configured to provide power quality metering, including precisely calibrated circuitry to accurately determine dynamics of one or more power lines. Power meters may include communications features that allow bi-directional communication with the meter. An integrated communications circuit allows the meter to communicate with other devices such as a computer, other meters, control panels and the like. The communications feature may communicate over an open network using a communication protocol.
• Certain classes of power meters are physically designed to be installed, or mounted, in a rack. The enclosure of a rack-mounted meter has predetermined maximum external dimensions to allow the meter to be inserted in a standard rack. The rack-mounted design also has electrical connections having a standardized configuration that allows the meter to be connected to standard connections on a rack. The arrangement of the electrical connections is fixed so that the rack-mounted meter may be used in standard configuration racks.
• Power metering needs often differ from installation to installation. The meter may need a customized configuration to be integrated within an existing power distribution system. Existing rack-mounted power meters needing such a customized configuration may have additional hardware installed under a front cover plate of the meter, or in some other location internal to the meter housing. Such an installation not only requires the meter be physically dismantled, but also requires removal of utility or verification seals. Removal of such seals requires that the meter be sent out to a verification shop, or otherwise taken out of service until the meter can be re-verified and/or inspected, and new seals applied by the appropriate third party.
BRIEF SUMMARY OF THE INVENTION
• By way of introduction only, a rack-mounted power meter includes a removable, or replaceable, externally mounted metering options module. The rack-mounted power meter and the metering options module may be mounted in a bay of an equipment rack. The architecture of the rack-mounted power meter may be achieved by one or more apparatuses, devices, systems, methods, and/or processes.
• The rack-mounted power meter is an adaptable power meter that may be modified and/or updated to meet current and future needs without requiring disassembly of the enclosure of the power meter, or disturbance of tamper-proof seals included on the power meter. A removable, metering options module may be mounted within a slot, cutout or shoulder of a meter housing of the power meter. The metering options module may be externally affixed to the rack-mounted power meter without exceeding the standard maximum external dimensions for a rack-mounted meter. Once mounted, the metering options module may be interfaced with, and enhance/change the functionality of metering circuitry included in the meter.
• The metering options module includes circuitry that provides various additional features and functionality to change, enhance or upgrade the functionality of the meter. The metering options module is self-enclosed and may be sealed with a tamper-proof seal that is independent of the power meter. The metering options module may be coupled with the power meter to provide the additional functionality. The metering options module may provide functions not presently provided by the metering circuitry present within the meter. The metering options module may provide functionality that may add to, augment, supplement or substitute for an existing metering circuitry function, whether that function is communications, metering, monitoring, control or the like. The metering options module also may provide alternate or new modes to monitor, measure, or calculate electrical parameters. The metering options module is removable without substantially affecting the essential functions of the power meter. In addition, the metering options module may be installed and removed without disturbing a tamper proof seal, such as a calibration seal included on the power meter. The metering options module may have a separate housing that meets the standard meter enclosure requirements for mounting in an equipment rack assembly.
• The foregoing summary is provided only by way of introduction. The features and advantages of the rack-mounted power meter having a removable metering options module may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims. Nothing in this section should be taken as a limitation on the claims, which define the scope of the invention. Additional features and advantages of the present invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a perspective front view of an example rack-mounted power meter that includes an external removable metering options module.
• FIG. 2 is a perspective front view of an example rack-mounted power meter ofFIG. 1 without an external removable metering options module mounted thereon.
• FIG. 3 is a perspective front view of an example rack-mounted power meter ofFIG. 1 that includes an external removable options module illustrated with a cover in an open position.
• FIG. 4 is a perspective rear view of the rack-mounted power meter ofFIG. 1 and an external removable metering options module.
• FIG. 5 is a perspective rear view of the rack-mounted power meter ofFIG. 1 without an external removable metering options module mounted thereon.
• FIG. 6 is a perspective rear view of an example rack-mounted power meter ofFIG. 1 illustrated with a cover in an open position that also includes an external removable metering options module.
• FIG. 7 is a front view of the rack-mounted power meter ofFIG. 1.
• FIG. 8 is a front view of the rack-mounted power meter ofFIG. 1 with a cover in an open position.
• FIG. 9 is a front view of another example of the rack-mounted power meter ofFIG. 1.
• FIG. 10 is a perspective front view of the rack mounted power meter ofFIG. 9, and a removable metering options module.
• FIG. 11 is a front view of the rack mounted power meter ofFIG. 9, with a removable metering options module mounted thereon.
• FIG. 12 is a rear view of the rack-mounted power meter ofFIG. 1 that includes an external removable metering options module.
• FIG. 13 is a rear view of the rack-mounted power meter ofFIG. 1 without an external removable metering options module mounted thereon.
• FIG. 14 is a perspective partially cutaway view of the rack-mounted power meter ofFIG. 1 illustrating an example of an internal connection for the rack-mounted meter ofFIG. 1.
• FIG. 15 is a perspective rear view of an example of a metering options module for the rack-mounted power meter ofFIG. 1.
• FIG. 16 is a rear view of an example of a metering options module for the rack-mounted power meter ofFIG. 1.
• FIG. 17 is a perspective front view of an example of a metering options module for the rack-mounted power meter ofFIG. 1.
• FIG. 18 is a front view of an example of a metering options module for the rack-mounted power meter ofFIG. 1.
• FIG. 19 is a block diagram of an example of a power meter and a removable metering options module ofFIGS. 1-18.
• FIG. 20 is a block diagram of an example of an input/output module that may be included in the metering options module.
• FIG. 21 is a block diagram of an example of a communications module that may be included in the metering options module.
• FIG. 22 is a block diagram of an example of an access key module that may be included in the metering options module.
• FIG. 23 is a perspective top view of an example of the rack-mounted power meter ofFIGS. 1-8 that includes an external removable metering options module, and is mounted in an equipment rack.
• FIG. 24 is a perspective front view of an example of the rack-mounted power meter ofFIGS. 1-8 that includes an external removable metering options module, and is mounted in an equipment rack.
• FIG. 25 is a perspective rear view of an example of the rack-mounted power meter ofFIGS. 1-8 that includes an external removable metering options module, and is mounted in an equipment rack.
DETAILED DESCRIPTION OF THE EMBODIMENTS
• A rack-mounted power meter having an externally mounted metering options module will now be described with reference to the accompanying drawings. In each of the following figures, components, features and integral parts that correspond to one another each have the same reference number. The drawings of the figures are not true to scale.
• A rack-mounted power meter having an externally-mounted removable metering options module may be embodied in many different forms, formats, and designs, and should not be construed as limited to the examples set forth herein. The architecture for the rack-mounted power meter includes apparatuses, distributed networks, methods, processes, data processing systems, and software and firmware device. Features of the rack-mounted power meter having a removable external metering options module may be embodied as electronic components instructions, software, and/or firmware utilizing a computer program product on a computer-readable storage medium, such as memory, solid state memory, hard disks, CD-ROMs, optical storage devices, or magnetic storage devices.
• Herein, the phrase “coupled with” or “coupled to” is defined to mean directly connected to or indirectly connected through one or more intermediate components. Such intermediate components may include both hardware and software based components. Further, to clarify the use in the pending claims and to hereby provide notice to the public, the phrases “at least one of <A>, <B>, . . . and <N>” or “at least one of <A>, <B>, . . . <N> or combinations thereof” are defined by the Applicant in the broadest sense, superseding any other implied definitions herebefore or hereinafter unless expressly asserted by the Applicant to the contrary, to mean one or more elements selected from the group comprising A, B, . . . and N, that is to say, any combination of one or more elements A, B, . . . or N including any one element alone or in combination with one or more of the other elements which may include, in combination, additional elements not listed.
• The rack-mounted power meter having an externally-mounted removable metering options module (referred herein as the rack-mounted meter) may be designed to meet requirements of national and international standards setting bodies, such as International Electrotechnical Commission (“IEC”), while providing a meter that provides a rack mount form factor. The described examples relate to an apparatus for measuring power parameters on a conductor, such as a power line. Further, the described examples relate to a mechanical and electrical design and system that monitors power parameters on low, medium and high voltage conductors.
• An example power meter may include metering circuitry comprising at least one processor capable of executing instructions stored in a memory of the power meter to direct the receipt and processing of signal(s) representative of power parameters. The metering circuitry may also include hardware, firmware and/or software based signal processing, filtering, and any other functionality related to monitoring and processing power parameters related to power quality and/or revenue metering. A global positioning system (“GPS”), and/or time-synchronization capabilities, that improve the measuring accuracy of the device and/or provide additional geo-location based capabilities may also be included in the metering circuitry of the power meter. Metering circuitry of example power meters may also include communications ports, antennas, either planar, GPS or both, facilitating ease of communication.
• FIGS. 1-3 illustrate a perspective view of an example rack-mountedmeter100. The rack-mountedmeter100 may be inserted and mounted to an equipment rack assembly (not shown). The equipment rack assembly may provide an electrical connector having an input/output (I/O) interface and operating power for themeter100. The rack-mountedmeter100 may be designed with a form factor having maximum external dimensions, such as dimensions that allow the rack-mounted meter to be used as a 48.3 centimeter equipment rack mounted meter. The rack-mountedmeter100 may be calibrated, and its meter housing may be sealed before being installed in a bay of an equipment rack assembly. The dimensions of themeter100 are implementation dependent and may vary depending upon the type of equipment rack and standard dimensions supported therein.
• Meter100 may be sealed by including one or more tamper proof seals on/in/around themeter100. The seal(s) may be external or internal tometer100. The seal(s) may be attached during manufacture, during installation, or following installation. A tamper-proof seal is a physical device or mechanism that provides an indication when the seal(s) has been tampered with, or disturbed. The seal(s) may be made of various materials, and come in various designs, such as an adhesive strip design, a wire design, a lock design, a glass vial design, a plastic tie design, an electrical fuse design, a gravitational design and/or an inertial/shock detector design. For example, when the seal is a plastic tie, the seal may generally include a tab with a unique identifier, and a locking mechanism that cannot easily be opened without breaking or otherwise visibly altering the locking mechanism.
• A tamper-proof seal can be applied to various parts of themeter100 to detect tampering. In addition, a seal can be applied to structure surrounding themeter100 to indicate removal and/or relocation of themeter100 with respect to the surrounding structure. Example seal applications include application to an access door or cover included on themeter100, application to a reset or other control button included on themeter100, application to the casing of themeter100, application to input/output points, and/or application to an external enclosure around at least a portion of themeter100.
• Themeter100 may have multiple tamper-proof seals that protect different parts of the device. Types of tamper-proof seals that may be used include seals used as revenue/verification seals, utility seals, or metering point identification seals. A revenue/verification seal may be controlled by a third party and verifies the accuracy of the meter. In the event a revenue verification seal is disturbed or broken, themeter100 may need to be returned to the third party for re-verification and re-sealing prior to being further used in revenue calculations. A utility seal may be controlled by a user of themeter100, such as an electrician at a utility, to guard against tampering. A metering point identification seal is a seal that may be used to uniquely identify themeter100 and keep track of the location of the meter within a facility or system.
• The rack-mountedmeter100 may integrate both power revenue metering and power quality class metering within an external form factor that may be rack-mounted in a bay. For example, the rack-mountedmeter100 may provide power quality analysis that meets Class A requirements of the IEC 61000-4-30 metering standard. The rack-mountedmeter100 may also be a revenue device that meets the requirements of IEC 62053-22. Accordingly, the rack-mountedmeter100 may provide power quality detection, monitoring, reporting, recording, analysis and communication along with revenue accuracy measurement and reporting. The rack-mountedmeter100 may integrate the features of power quality monitoring and revenue metering in a single power meter having a meter housing meeting the form factor requirements for installation and mounting in a bay of an equipment rack assembly. Examples of a power quality meter integrated with a revenue meter are described in U.S. Pat. No. 6,615,147, for a REVENUE METER WITH POWER QUALITY FEATURES, issued on Sep. 2, 2003, and U.S. Pat. No. 6,792,364, for a REVENUE METER WITH POWER QUALITY FEATURES, issued on Sep. 14, 2004, both of which are incorporated by reference in their entirety herein.
• In one example, the rack-mountedmeter100 is configured to meet the IEC 61053-22 standard that also provides power quality analysis to the IEC 61000-4-30 standard class A. Themeter100 may be configured to meter single-phase or multi-phase power systems and loads, or combinations thereof. Themeter100 may be coupled with one or more conductors. The conductors may be power cables, high tension lines, bus duct, bus bar, substation terminals, generator terminals, circuit breaker terminals, and/or any other mechanism, device, or materials capable of conducting current and voltage. The conductor may be part of a two-wire, three-wire, and/or four-wire power system. Themeter100 may provide measurement of voltage and current to determine active, reactive, and/or apparent energy over a range of frequencies, or combinations thereof. In addition, themeter100 may provide power quality measurement and processing of power parameters such as voltage and current harmonics, voltage and current inter-harmonics, voltage and current anomalies, such as sag/swell(s) or transient(s), and/or any other power quality related data and analysis.
• The rack mountedmeter100 includes ameter housing102. Themeter housing102 may have an external form factor, or frame structure, that is dimensioned to allow rack-mounting of themeter100 in a bay of an equipment rack. Thus, an outer envelope of themeter housing102 may be formed to fit within at least one bay of an equipment rack. Themeter housing102 may include at least six sides, and may be generally characterized by width, height, and length dimensions. Themeter housing102 provides mechanical protection for metering circuitry included in themeter housing102. Themeter housing102 may be configured as an IP51 enclosure as set forth by IEC 529, providing protection to the metering circuitry against inadvertent intrusion of tools and/or wires over 1 mm in diameter. Themeter housing102 also may provide protection against vertically falling drops of water, condensation and other moisture. Themeter housing102 may be designed to minimize holes, cutouts, spot welded tabs, folded seams, and connector openings, and may have a rust inhibiting coating such as a powder coat finish, paint or other protective coating. Themeter housing102 may provide mechanical protection, fire protection, electromagnetic protection against radio-frequency interference, and electrical shock protection.
• Themeter housing102 may include a two-tiered surface108 that includes a first portion108aand a second portion108b. InFIGS. 1-3, the first portion108ais a front portion and the second portion108bis a rear portion of themeter housing102. The first portion108amay be substantially planar across the width of the two-tiered surface108, and extend a predetermined depth of themeter housing102 from afront panel104 of the rack-mountedmeter100 towards amid portion110 of the two-tiered surface108. The second portion108b, or slot, may be substantially planar across the width of themeter housing102 and extend from themid portion110 to an end of themeter housing102, such as a rear112 of themeter housing102. The second portion108bmay be recessed from the first portion108ato form a slot.
• Themeter housing102 may also include anelectrical connector panel106. Theelectrical connector panel106 may include a first connector panel106aand a second connector panel106b. The first connector panel106amay be a step or shoulder formed as a portion of themeter housing102 that connects the first portion108aof the two-tiered surface108 to the second portion108b. The first connector panel106amay be substantially planar across the width of themeter housing102, and may be positioned approximately orthogonal to both the first portion108aand the second portion108bof the two-tiered surface108.
• FIGS. 1 and 3 illustrate ametering options module114 that is designed to be coupled with and mounted to the rack-mountedmeter100.FIG. 2 illustrates the rack-mountedmeter100 without themetering options module114 coupled with the rack-mountedmeter100. The enclosure of themetering options module114 may be characterized by a width, height, and length dimensions. Themetering options module114 may include a housing that is designed to provide mechanical protection for circuitry enclosed within similar to that described above for themeter housing102 of the rack-mountedmeter100. In the illustrated example, the enclosure of themetering options module114 has six sides. In another embodiment, themetering options module114 may include a housing that is completed after themetering options module114 has been mounted to, or otherwise installed on, the rack mountedmeter100, e.g. themetering options module114 features at least one open face that is covered by a face of themeter100 when themetering options module114 is installed. In this example, themetering housing102 may be a sealed unit that is an IP51 enclosure as set forth by IEC 529. In addition, or alternatively, the housing formed by the combination of themetering options module114, and themeter housing102 may be an IP51 enclosure as set forth by IEC 529.
• Themetering options module114 may be coupled with the rack-mountedmeter100 proximate the two-tiered surface108. The surface of the second portion108bof the rack-mountedmeter100 may be recessed from the surface of the first portion108aa determined distance that allows themetering options module114 to be mounted contiguous with the second portion108b. In one example, the uppermost portion of themetering options module114 may be substantially flush with the first portion108a. That is, a height of the first portion of the first connector panel106ais at least the height of an upper surface of themetering options module114. In addition, the length of the second portion108bmay be at least as long as a length of themetering options module114, and the width of themetering options module114 may be no wider than the width of the rack-mountedmeter100. In the illustrated example, the length of the second portion108bis slightly longer than themetering options module114 to allow room for connectors and associated conductors, such as signal cables, to be terminated at themetering options module114.
• Accordingly, when themetering options module114 is affixed to themeter100, themetering options module114 may be substantially flush with the upper surface108a. In one example, the exposed upper surface of themetering options module114 does not extend beyond the upper surface108a. Additionally, or alternatively, the external dimensions of themeter100 with themetering options module114 mounted thereto may not exceed the maximum dimensions required for themeter100 and themetering options module114 to be installed in a bay of an equipment rack assembly. Thus, an outer envelop of themeter100, with our without themetering options module114, may be dimensioned to fit within the dimensions of a bay of an equipment rack assembly and be securely mountable therein.
• Themetering options module114 may be coupled with themeter housing102 with afastener117. Thefastener117 may be a screw, a rivet, a clasp, a latch, a snap, or any other mechanism capable of holding themetering options module114 in position on a surface of themeter housing102. InFIGS. 1-3, thefastener117 is a plurality of fasteners each formed with a threaded post and a nut. In other examples, any other form of fastener, in any other position capable of coupling themetering options module114 and themeter housing102 may be used.
• FIGS. 1 and 3 illustrate an examplemetering options module114 mounted substantially flush with the two-tierupper surface108 of the rack-mountedmeter100. In other examples, themetering options module114 may be otherwise coupled with the rack-mountedmeter100. For example, themetering options module114 and rack-mountedmeter100 may be configured with a two-tier side surface, or a two tiered bottom surface, where themetering options module114 is mounted to be no greater than flush with the external dimensions of the rack-mountedmeter100. Alternatively, or in addition, additional external surfaces of themeter100 may be two-tiered to allow more than onemetering options module114 to be mounted to the rack-mountedmeter114 and yet stay within the dimensions of a bay of an equipment rack.
• Themetering options module114, when mounted on themeter100, may have a first surface that is contiguous with the second surface108b, and a second surface opposite the first surface that is substantially flush with the maximum external dimensions of themeter housing102. Thus, first surface of the metering options module may be substantially parallel with a surface of the second portion, and the second surface of themetering options module114 may be in substantially the same plane with the surface of the first portion108aof themeter100.
• In another example, themeter housing102 may have a slot, cavity or opening in which themetering options module114 may be inserted. The slot may be formed in the front, back, top, bottom or side of themeter100, and be an externally accessible surface of themetering housing102. Themeter housing102 may form the cavity. Themeter housing102 may remain a sealed unit that is an IP51 enclosure as set forth by EEC 529. A hinged or otherwise movable cover, or trap door, may be positioned to cover an entrance to the cavity.
• The cover may be moved from a closed position to an open position to allow themetering options module114 to be inserted into the cavity through the entrance. Themetering options module114 may be securely held in the cavity with the cover. The cover may minimize entry of dust and moisture into the cavity. In addition, the cover may have a security mechanism such as a lock and key, a biometric device, such as a fingerprint scanner, or any other device that provides verification of identity so that only authorized personnel are allowed access to the cavity. In addition, or alternatively, the cover could be sealed with a tamper proof seal, such as a utility seal, and/or a revenue seal once themetering options module114 is installed in the cavity and the cover is moved to a closed position. The number and type of tamper proof seal(s) is dependent on the operational functionality of themetering options module114.
• Themetering options module114 represents self-enclosed, sealed, additional functionality that may be added to themeter100. Such functionality may include additional power parameter processing capability, signal conditioning capability, input/output capability, and/or any other hardware, firmware and/or software to reconfigure, enhance, or otherwise change the functionality of themeter100. In one example, themetering options module114 may provide enhanced communication capability and associated input/output hardware. In another example, themetering options module114 may provide increased capability to transmit and receive input and/or output signals. In still other examples, the metering options module may provide hardware, software and input/output signal capability to enable protective relaying functionality. In yet another example, themetering options module114 may provide power quality event hardware, software and input/output capability.
• Thefront panel104 of the rack-mountedmeter100 may have a flip-upcover115.FIGS. 1 and 2 illustrate the rack-mountedmeter100 with thecover115 in a closed position, andFIG. 3 illustrates thecover115 in an open position. The flip-upcover115 may be hinged so that thecover115 swings through an arc to an open position, exposing acontrol panel116. At least a portion of thecontrol panel116 may be located underneath or behind thecover115. Other portions of thecontrol panel116 may be accessible when thecover115 is in a closed position. Thecontrol panel116 may include connectors, such as analog, digital and/or optical connectors. In addition, as described later, thecontrol panel116 may include user interface devices, such as, buttons, knobs, switches or any other user input/output devices or mechanisms that provide access and control of themeter100.
• With thecover115 closed, one or more connectors, buttons, switches, and/or other user interface devices for access and control of themeter100 may be covered and inaccessible, while other connectors, buttons, switches, and/or any other user interfaces may be accessible through thecover115. In addition, user interface devices may be included on the cover. Access to controls when thecover115 is in the closed position may include only that functionality that will not affect operation. The remaining controls may be inaccessible to a user with limited security access when thecover115 is closed. When additional control inputs are to be provided to themeter100, thecover115 may be opened, exposing the features beneath.
• Ascreen118, such as an LCD, LED, plasma or other digitally controlled display may be positioned on thefront panel104. The screen may be a touch-screen device allowing a user to input data and selections by touching appropriate areas on thescreen118. Thescreen118 may be viewable with thecover115 in the closed and opened positions. Thus, thescreen118 may be positioned on thecontrol panel116 or mounted on thecover115. In one example, when thescreen118 is on thecontrol panel116, portions of thescreen118 may be blocked when thecover115 is closed, e.g. to prevent viewing of particular data.
• Thescreen118 may include a graphical user interface that allows the user to input data, configure parameters for themeter100, set controls, and/or receive information from themeter100. The user may input a selection directly through thescreen118, and/or may input data using any one of combinations of the other user interface devices, such as buttons, switches and knobs included on thecontrol panel116. For example, using the buttons provided at thefront104 of themeter100, the user may scroll or navigate through an options menu on thescreen118 to configure themeter100, assign communications protocols for themeter100, display output parameters, set input metering parameters and/or control any other features of themeter100. The options menu may be a cascading or hierarchical menu where selections of options on a menu may provide a subset of options provided on another menu that is displayed to the user. Thescreen118 may also be used to provide a visual indication of the operation of themeter100.
• Themeter100 may be configured to provide multiple levels of security to protect themeter100 from being tampered with or inadvertently or mistakenly mis-programmed. For example, access to the options menu and/or portions of the options menu may be accessible only after a user has entered a password or authentication code. Similarly, where themeter100 is being accessed for programming using an external processor in communication with themeter100 through a communications port, access to programming features may be set according to a password entered. The password may be associated with a high-level programming or calibrating access, such as by a third party manufacturer and/or calibrator. Another authorization level may be associated with general configurations set-up. For example, another password may be associated with general scrolling or navigating to select various outputs, and/or restricting inputs or reconfiguring of themeter100.
• The level of access may be determined by a password or other authentication means, such as a biometric device, or any other mechanism for identifying a user. Themeter100 may be accessed by multiple users, each having a distinct password. Access to various parameters of themeter100 may be determined or restricted by the password as well. For example, one user may have access only to power quality parameters based on the password associated with the user, and another user may have access to revenue parameters based on the associated password. The password also may restrict the user's privileges to read, or read and write data provided by themeter100.
• Thefront face104 may be configured to be mounted and affixed to corresponding members of a standard equipment rack system. Thefront face104 may have handles or grabbars120 that allow an installer to carry themeter100, and to position themeter100 in or with an equipment rack assembly. Thehandles120 may be installed at thefront face104 towards the vertical edges of thefront panel104. Thefront panel104 also may include amechanical coupler122, such as a screw, bolt, or wing nut that allows themeter100 to be affixed to a rack assembly. Themechanical coupler122 may also be used to form a tamper proof seal, such as a utility seal so that themeter100 cannot be removed from the equipment rack without disturbing, damaging, or otherwise changing the tamper proof seal to indicate such activity has occurred.
• FIGS. 4-6 illustrate perspective views from the rear of the rack-mountedmeter100.FIGS. 4 and 5 illustrate the rack-mountedmeter100 with thecover115 in a first position that is a closed position, andFIG. 6 illustrates the rack mountedmeter100 with thecover115 in an open position.FIGS. 4 and 6 illustrate themetering options module114 attached or otherwise mounted to the rack-mountedmeter100 at the second portion108b, andFIG. 5 illustrates the rack-mountedmeter100 without themetering options module114 mounted or otherwise affixed to the rack-mountedmeter100.
• FIG. 5 also illustrates the first connector panel106aof themetering housing102. An externally accessible meter housingelectrical connector130 may be installed on the surface of the first connector panel106ato provide an electrical connection from the rack mountedmeter100 to themetering options module114. In one example, themeter housing connector130 is a multiple-pin connector providing power to themetering options module114 as well as multiple I/O connections, such as communications and control signals. When themetering options module114 is installed on the rack-mountedmeter100, a corresponding electrical connector is coupled with the meter housingelectrical connector130 on the rack-mountedmeter100. In one example, themeter housing connector130 is a pin connector, such as a fifty pin connector, that is configured to accept an edge connector of themetering options module114. The first connector panel106amay also include guide pins131. The guide pins131 provide for mechanical alignment of themetering options module114 with themeter100 when themetering options module114 is being positioned on themeter housing102. The guide pins131 may be provided at the first connector panel106ato guide themetering options module114 to themeter100 when themetering options module114 is mounted to themeter100.
• The rear of themeter housing102 also may include the second connector panel106b. The second connector panel106bincludes at least one rackelectrical connector128 for connecting themeter100 to one more rack electrical connectors included in an equipment rack assembly. Therack connector128 may be arranged according to a predetermined and/or standardized configuration or arrangement. In one example, therack connector128 may be a plurality of pins arranged according to a predetermined configuration where the position of a pin corresponds with a signal, power, or ground connection. Through therack connector128, signals related to the voltage and/or current of one of more conductors that themeter100 may monitor or measure are inputs to themeter100. The position of the pins of the rackelectrical connector128 may be assigned to a particular or discrete voltage, current, or power input signal. For example, a pin may be assigned to receive a voltage signal of one phase of a multiphase voltage system, a voltage signal of a single phase system, or a reference or neutral of a multi-phase or single phase voltage system. Similarly, a pin may be assigned to receive signals related to current on a conductor.
• The rackelectrical connector128 may be one or more pin or plug-type connectors, sleeve or socket type connectors, or combinations thereof. Theconnector128 may be coupled with one or more corresponding connectors in an equipment rack assembly (not shown) when themeter100 is installed or otherwise mounted in a bay of an equipment rack assembly. The pins may be slid into corresponding sleeves or receptacles, and the sleeves may accept corresponding pins on the equipment rack assembly. In one example, therack connector128 includes multiple Essailec connectors, manufactured by ABB Entrelec of Irving, Texas, that are arranged in a predetermined configuration on the second connector panel106bof themeter100. Therack connector128 may include coding or keying pins that mate with corresponding keying or coding pins on the rack electrical connector(s) in the equipment rack assembly when themeter100 is installed in the bay of the equipment rack.
• In one example, where therack connector128 is a plurality of Essailec connectors, there are a plurality of coding pins, such as four coding pins, associated with each Essailec connector. The coding pins may have an external contour or shape that provides a unique profile for the coding pin depending on the orientation of coding pin in its housing. The coding pin may be oriented in one of several clock positions with respect to therack connector128 with which it is associated. The coding pin will engage with the corresponding pin in the electrical connector in the equipment rack assembly, only when both pins have a corresponding orientation. The coding pins may be oriented or keyed according to the arrangement or layout of therack connector128 on themeter100. The coding pins may therefore prevent ameter100 from being mis-racked or installed in an improper socket on the equipment rack.
• The coding pins also may be arranged to identify a configuration of themeter100, and/or identify a feature set, or group of functionalities of themeter100. The identified feature set may include parameters for how aparticular meter100 is configured and/or functionality provided by themeter100. For example, the feature set may include digital input or output configurations, analog input or output configurations, Ethernet and communications configurations, GPS time sync capabilities, antenna connections for wireless devices (e.g., 802.11 and the like), wireless mesh networks, Zigbee, Wi-Fi, and the like. The coding pins may be assigned to each feature set such that a predefined coding pin, or arrangement of one or more coding pins, may identify the functionality present within aparticular meter100.
• Aground lug126 also may be provided on the second connector panel106bof themeter100 to provide grounding and bonding of themeter100 to the equipment rack assembly. In one example, theground lug126 is a threaded stud in electrical continuity with exposed conductive members of themeter housing102. Theground lug126 also may be coupled with one or more grounded buses internal to themeter housing102. In other examples, theground lug126 may be positioned elsewhere on the surface of themeter housing102. In still other examples, one or more of thefasteners117 may be used to ground themetering options module114 and/or themeter100.
• Themetering options module114 may be coupled with themeter100 with atab124 included on themetering options module114. Thetab124 may be configured to be coupled with theground lug126. InFIGS. 4-5, thetab124 includes an opening that allows thetab124 to be slide over theground lug126 on the second connector panel106bof themeter100 and be fastened thereto with a fastener, such as a nut. Themetering options module114 may be secured, bonded and grounded with thepower meter100 through the electrical connection to theground lug126. In one example, theground lug126 is a threaded stud and thetab124 of themetering options module114 may be secured to theground lug126 through a paint breaking bonding nut that is secured to a threaded stud that forms theground lug126. Theground lug126 may also be positioned to allow grounding and bonding of themeter100 to an equipment rack assembly.
• In one example, the second connector panel106bof themeter100 includeslances132. Thelances132 may be projections formed in, or fasteners coupled with, themeter housing102 on or in proximity to the second connector panel106bof themeter housing102. Themeter100 may include an internal chassis that is inserted or slid into themeter housing102. InFIGS. 4-6, thelances132 are screws that include an aperture, and may be used to fasten the internal housing to themeter housing102. Thelances132 may be used to couple tamper-proof seals to themeter100. Themeter100 may be assembled, calibrated and verified by a third party to be operational and to be capable of use to report on metering conditions and parameters within predetermined tolerances. Once verification is complete the internal chassis may be slid into themeter100, and one or more tamper-proof seals may be applied to thelances132. In one example, theground lug126 may also include a lance capable of being used to install a tamper-proof seal for the ground lug and/or the slidable chassis.
• After themeter100 has been verified to operate within determined tolerances, themeter100 may be sealed with a tamper-proof seal. The tamper-proof seal may be a revenue seal that provides verification that themeter housing102 has not been opened or otherwise disturbed following calibration. In one example, verification sealing of themeter100 is completed by threading wire though one ormore lances132 in the second connector panel106bof themeter100. The ends of the wire that is threaded through thelances132 may also be threaded through an aperture formed in acleat133 included on themeter housing102. Thecleat133 may be positioned on themeter housing102 and may be accessible after themeter100 has been assembled. After the wire is threaded through thelance132 and thecleat133, the ends of the wire may be tied, clamped or otherwise permanently affixed together. Thelance132 also may be configured to secure the ends of the wires. Thus, in the illustrated example, thelance132 cannot be unscrewed to access the internal chassis without breaking, or otherwise disturbing the wire threaded through thelance132 and thecleat133, which would indicate tampering had occurred.
• A wire also may be threaded through a lance (not shown) in themetering options module114 and secured to themeter100 to create a tamper proof seal. Themeter housing102 of themeter100 may not be opened without breaking, or otherwise creating indication of such activity with the tamper-proof seal. In addition, separation of themetering options module114 from themeter100 may not occur without breaking, or otherwise creating indication of such activity with the tamper-proof seal. In other examples, the tamper-proof seal may be omitted to enable discretionary removal and installation of themetering options module114 without disturbing any tamper-proof seals.
• FIGS. 7 and 8 illustrate a front view of an example of the rack-mountedmeter100 that includes thefront panel104 of themeter100. Thefront panel104 provides a user interface for themeter100.FIG. 7 illustrates an example of thefront panel104 of themeter100 with thecover115 in a closed position. In the closed position, access to the user interface may be limited, however a set of input/control buttons136 may remain accessible.
• FIG. 8 illustrates thefront panel104 of themeter100 with thecover115 in an open position, exposinginput keys146, indicators147 (such as LEDs), and a battery cover orbattery compartment149, at least some of which may be concealed when thecover115 is in a closed position. Thecover115 may be closed to conceal other buttons, switches, connectors, lights, and the like on thecontrol panel116. Thecover115 may be secured in the closed position by the weight of thecover115, by a snap fit, by a mechanical coupler, or any other mechanism for securing thecover115 in a closed position. Thecover115 may be configured to be open by hand or through the use of a specialty or off-the-shelf tool. Thecover115 may also be held in the closed position with a tamper-proof seal.
• Thedisplay118 is positioned at thefront panel104 to provide data input and output. Thedisplay118 provides a graphical interface for themeter100. Information gathered, metered, collected or otherwise compiled by themeter100 may be displayed on thedisplay118. For example, thedisplay118 may display the current status of power used by a load being monitored by themeter100. Thedisplay118 may also provide a visual or graphic display of a phasor diagram for the load and/or supply. A user may also use thedisplay118 to input control commands to themeter100 and/or scroll through an options menu to configure themeter100, set metering parameters and alarm conditions, select communications protocols, assign communications protocols to input/output communications ports, and/or select an output from themeter100 for viewing, control and/or further processing.
• Thedisplay118 may be used in combination withscroll buttons136 to scroll through the menus of themeter100. In one example, thedisplay118 is a touch screen that allows the user to input commands, and otherwise make selections from an options menu using thedisplay118. Thedisplay118 may also be configured to recognize or identify the user, and grant access to features, functions and parameters of themeter100 based on recognition of the user. For example, thedisplay118 may be configured to recognize or identify a user by analyzing the user's biometric data, such as a fingerprint, when the user touches thescreen118. Themeter100 may include a fingerprint recognition mechanism that allows identification of a user's fingerprint. After the user is recognized, the level of access to features and functions of themeter100 may be determined based on a predetermined authorization level. Accordingly, the user's biometric information may be used for granting access and determining access levels for the user within themeter100.
• Thedisplay118 also may provide a visual indication of an alarm condition. For example, thedisplay118 may be configured to have a selected background color during operating conditions, and another distinct background color when an alarm condition is detected. The background color of thedisplay118 may change color and/or flash when an alarm condition is detected. For example, if themeter100 detects a power outage, a low voltage condition, an overload condition, or measure a parameter outside a preset limit, themeter100 may indicate the corresponding alarm condition on thedisplay118 by changing the background color on thedisplay118. A message also, or alternatively, may be flashed on thedisplay118. The visual alarm indicator of thedisplay118 may be accompanied by an audible alarm and/or a communications output indicating the detected alarm condition.
• The user may select from a variety of communications protocols over which themeter100 may communicate with other devices, such as computers, processors, controllers, loads and meters. The user may select the communications protocol from a selected menu displayed on thedisplay118. The communications protocol also, or alternatively, may be set from a computer or other controller coupled to themeter100, either through a rack assembly, at the factory during assembly, through a universal serial bus (“USB”) port, through an optical port, through a hard-wired connection, or through a wireless communications transmission with themeter100. Themeter100 may be configured to communicate using one or more communications protocols, including TCIP, SCADA, Modbus, ION, RS232, RS485, and Device Language Message Specification (“DLMS”), DNP, IEC 61850 protocols and the like.
• Thefront panel104 may include one or moreoptical communications ports142. In one example, theoptical communications ports142 are configured according to IEC 1107, ANSI C12, and/or IRDA standards. Theoptical communications ports142 may be accessible throughopenings138 in thecover115. Theoptical communications ports142 may provide access to communications with themeter100 through the user interface provided by thefront panel104 of themeter100.
• Theoptical communications ports142 may also be configured to provide parallel communications. Thus, in the example ofFIG. 8, eachoptical communications port142 may be configured to independently communicate with a communications device external to themeter100. Theoptical communications ports142 also may be configured to provide series communications. The series communication may be duplicative of communications of one of theother ports142. Thus, using theoptical communications port142, themeter100 may be configured to communicate with a plurality of external devices, such as three different devices.
• Thecommunications ports142 may each have acommunications indicator144 that signals when communication with thecorresponding port142 is active, such as through a visual indication. In one example, thecommunications indicator144 is one or more LED's positioned proximate to theoptical communications port142. Thecommunications indicators144 may illuminate when the correspondingcommunications port142 is active. Each of thecommunications indicators144 may be encased in a clear diffuser positioned around each of theoptical communications ports142. The diffuser may be illuminated when the correspondingcommunications indicator144 illuminates. Thecommunications indicator144 may be configured to distinguish between inbound and outbound communications, such as by corresponding distinguishing colors. Thecommunications indicator144 also may be configured to provide a visual indicator when the communications is lost or to indicate an alarm condition, such as by flashing.
• Thefront panel104 also may provide a universal serial bus (USB)port140 for wired communications with other devices. TheUSB port140 enables themeter100 to be connected to any USB compatible device, such as, for example, portable computers and portable communications devices. Themeter100 also may be configured for wireless communications, such as by using Wi-Fi, Bluetooth, mesh and Zigbee standard communications protocols and/or combinations thereof. Using the wireless communications, and/or USB port, themeter100 may communicate and share data and control with other devices.
• Themeter100 may have a redundant, back-up power supply or reserve energy storage device (not shown). The redundant power supply may be available to provide power for the operation of themeter100 in the event of a power supply failure to themeter100. The redundant power supply may automatically take over supplying power to themeter100 in the event of a power failure. In one example, the back-up power supply is a battery back-up.
• In the event of a power failure, themeter100 may sense the power failure and switch over to the back-power supply. Themeter100 also may enter into a power down or sleep mode until electrical energy is sensed on the conductor(s) being monitored by themeter100.FIG. 8 illustrates an example of abattery compartment149 which may provide an enclosure for one or more back-up batteries. Thebattery compartment149 is concealed by thecover115 and is accessible only when thecover115 is open. In another example, the back-up power supply may be a capacitor or capacitor bank that may store energy that may be used in the event of a power failure. Themeter100 also may be powered by one or more phases of the power supplied on the conductor(s) to which themeter100 is connected to monitor. Themeter100 also may have a dedicated AC power supply or dedicated DC supply from a stationary battery.
• FIG. 9 illustrates a front view of another example of the rack-mountedmeter100 that includes thefront panel104 of themeter100. In this example, thecover115 is illustrated as open, and in addition to the user interface devices, such as thedisplay118, thefront panel104 includes aslot180 formed in thefront panel104. Theslot180 may be formed in an externally accessible surface of the meter housing. The meter housing may remain a sealed unit that is an IP51 enclosure as set forth by IEC 529.
• Theslot180 may be dimensioned to receive themetering options module114. Theslot180 may have a removable and/orretractable slot cover181 that covers an opening to theslot180. The meter housing electrical connector130 (FIG. 5) may be disposed in theslot180 and positioned to engage an electrical connector mounted on themetering options module114.
• FIG. 10 is a perspective view of anexample meter100 that also includes a perspective view of a removablemetering options module114. In this example, themetering options module114 is dimensioned to fit within theslot180. Thus, the two-tiered surface108 (FIG. 1) may be omitted. Themetering options module114 may include a plurality of input/output (I/O)ports150. As described later, the I/O ports150 may provide an interface to other devices and/or equipment.
• FIG. 11 is a front view of themeter100 ofFIG. 9 with themetering options module114 installed in theslot180. The I/O ports150 may be positioned to be accessible when thecover115 is in the open position. A tamper-proof-seal may be applied once themetering options module114 is positioned in theslot180. An electrical connector (not shown) mounted on a surface of themetering options module114 may be positioned to engage a surface mounted electrical connector disposed in theslot180 when themetering options module114 is positioned in theslot180. The I/O ports150 may also include a ground lug. Alternatively, or in addition, themetering options module114 may be grounded when the electrical connectors engage within theslot180.
• FIGS. 12 and 13 illustrate rear views of an example of the rack-mountedmeter100 also illustrated inFIGS. 1-6.FIG. 12 illustrates the rack-mountedmeter100 with themetering options module114 attached or otherwise coupled with, or mounted to an externally accessible surface of the rack-mountedmeter100, andFIG. 13 illustrates the rack-mountedmeter100 without themetering options module114 coupled, mounted, or otherwise affixed to the rack-mountedmeter100.
• FIG. 12 also illustrates one or more I/O ports150 included on a rear panel of themetering options module114. The I/O ports150 may be communication ports that are enabled for communication when themetering options module114 is coupled with themeter housing102. Alternatively, or in addition, the I/O ports150 may be signal ports, such as analog and/or digital signal ports. In other examples, the I/O ports150 may be on any other surface of themetering options module114.
• In another example, the I/O ports150 may be in the form of one or more options rack electrical connectors. The options rack electrical connector(s) may be formed and position on the rear panel of themetering options module114. In other examples, the options rack electrical connector may be positioned on any other externally accessible surface of themetering options module114.
• When themetering options module114 is mounted on themeter100 and racked into a bay of an equipment rack, the options rack electrical connector may be engaged with an options rack electrical connector included in the equipment rack. Upon engagement, inputs and/or outputs external to themeter100 and/or themetering options module114 may be provided to themetering options module114 via the engaged options rack electrical connectors. The options rack electrical connectors may be pluggable panel mount connectors which may include wiring harnesses, or any other form of electrical connectors, as discussed herein. In one example, the pluggable panel mount connectors may be Essailec connectors. The options rack electrical connectors in the equipment rack may be pre-wired in a predetermined configuration, and/or may be installed and wired for themetering options module114.
• Themeter100 may be configured as an intelligent electronic device (IED). As an IED, themeter100 may be configured to provide control of other devices in a Master/Slave arrangement. In one example, themeter100 is configured to communicate with other metering devices using a Modbus and/or Modbus TCP communications protocol to provide control functions for those devices. Themeter100 may be set up as a Master where other devices on the network are slaves. The slaves may communicate information back to Master. The Master (meter100) may handle communication of the information through the network to other network coupled devices, such as controllers. Themeter100 also may be compatible with an object-oriented architecture.
• Themeter100 also may have modular capability so that it may be configured to operate according to a limited set of functions. Examples of such IED, object-oriented architectures, master/slave power monitoring devices, and module configurations for power meters are described in U.S. Pat. No. 6,871,150, entitled Expandable Intelligent Electronic Device, U.S. Pat. No. 5,650,936, entitled Power Monitor Apparatus and Method With Object Oriented Structure, and U.S. Pat. No. 5,828,576, entitled Power Monitor Apparatus and Method With Object Oriented Structure, each of which is incorporated by reference in its entirety herein.
• FIG. 13 illustrates the first connector panel106aof the meter housing having the externally accessible meter housingelectrical connector130 for providing electrical connection to themetering options module114. The externally accessible meter housingelectrical connector130 may be installed on the first connector panel106ato provide an electrical connection from the rack mountedmeter100 to themetering options module114. Theelectrical connector130 may provide electrical connections to a corresponding electrical connector on themetering options module114.
• As shown inFIGS. 12 and 13, the second connector panel106bof themeter housing102 may provide rackelectrical connector128 for use with the equipment rack assembly. The rackelectrical connector128 may be one or more electrical connectors arranged in a standard configuration at the second connector panel106bof themeter100. The rackelectrical connectors128 may be configured to be coupled to, or engaged with, corresponding rack electrical connectors provided in the equipment rack assembly in which themeter100 may be mounted. The electrical connectors may have a standard arrangement, or configuration, where the position of an electrical connector corresponds with a signal, power, or ground connection in the equipment rack assembly. For example, the connectors are pins that are slid into corresponding sleeves or receptacles on the rack assembly, as previously discussed.
• In one example, the electrical connectors are Essailec connectors that are keyed or arranged to provide an advanced feature set for input and output between themeter100, the equipment rack assembly, and/or devices connected to themeter100 through the equipment rack assembly. One end of the Essailec connectors may be mounted and coupled to one or more printed circuit boards. Each printed circuit board includes traces that route connections to the connector from a common connection point on the printed circuit board for all connectors. The printed circuit board may be installed on the chassis of themeter100, and internal connections to the Essailec connectors may be made through the circuit board to internal connectors of themeter100. Mounting the Essailec connectors to the circuit board provides an efficient quick means for installing or otherwise assembling the connectors in themeter100.
• Themeter100 may include a map of the rack connector(s)128 stored in memory. The map may be used by the processor to determine whether appropriate connections are made when themeter100 is installed in the equipment rack. For example, themeter100 may be programmed to detect whether the Essailec pins are connected to a circuit when themeter100 is installed in the equipment rack assembly. In one example, a lookup table may store a bitmap of the connections of the rack connector(s)128. When themeter100 is installed and configured by a user, the bitmap may be referenced to ensure that the expected connections at the rack connector(s)128 are present. The expected connections may be determined based on measurement of signal and/or voltage levels, measurement of test signals transmitted through the connections, or any other method, mechanism or device capable of determining that the connections are present. For example, if a connection is measured expecting between 100V and 120V, and that is what is measured, the connection is verified.
• Connection verification may also involve themetering options module114 for certain signals, such as communication signals. In addition, themetering options module114 may be used to generate and/or enable the generation of test signals to verify the connections. For example, themetering options module114 may be in communication with an external device capable of generating test signals to the connections in the equipment rack. Thus, the metering circuitry may direct the external device via themetering options module114 to output test signals to verify the connections.
• If the expected connection is not present, an alarm or other indicator may be generated by the metering circuitry. For example, a message may be displayed to a user through thescreen118. (FIG. 8) Themeter100 also may be configured to display a map of the rack connector(s)128 on thescreen118.
• In one example a user may select to display a map of the connections on thescreen118. The map may be displayed to show which of the connectors/pins has an electrical connection, when inserted in a bay of an electrical equipment rack. A pin having an electrical connection may be displayed in the map with a color or shading different from a pin without an electrical connection. For example, all connectors having electrical connections may be illustrated as black dots on the map and those connectors without a connection may be displayed in the map as a circle. Alternatively, or in addition, a signal level value of each connector/pin having an electrical connection may be displayed.
• At least one of therack connectors128 located at the second connector panel106bof themeter100 may be configured to provide an analog input/output connection. The analog I/O connection may provide analog communications signals between themeter100 and other devices. The analog connection may be used t provide information from themeter100. Additionally or alternatively, the analog connection may be used to receive information by themeter100.
• One example, connection to an analog I/O pin may enable themeter100 to be aligned with absolute time, independent of an operating system time of themeter100. Therefore, an analog pin may be used as a port for a global positioning system (GPS) signal for purposes of time synchronization. Using IRIG GPS signals, the input signals to themeter100 may be time-stamped and synchronized. The IRIG GPS signal may be continuously monitored by themeter100, or sampled. In one example, an IRIG B GPS signal is received by themeter100. A Field Programmable Gate Array (“FPGA”) included in the metering circuitry may decode the received IRIG B signal, and generate an interrupt signal at a fixed time relative to the start of an IRIG B packet. A processor, such as a CPU, may receive or detect the interrupt and thereby generate an accurate time stamp. The processor reads the IRIG B packet from the FPGA. The IRIG GPS connection on the rack-mountedmeter100 also may be provided through other connections to themeter100 such as wireless transmission and/or reception, IRIG B, and serial communications.
• Another connection supported by the rack connector(s)128 may be a watchdog signal generated by the metering circuitry included in themeter100. For example, a “heartbeat” signal may be periodically provided at one of the connections. The heartbeat signal may be present when themeter100 is operational and/or operating. The signal may be monitored by an external controller or processor. When themeter100 is not operating or operational, the heartbeat signal will cease, triggering an alarm or other indicator that themeter100 may have failed or may be in the process of failing.
• FIG. 14 illustrates a perspective view of an example of themeter100 with a portion of themeter housing102 removed to show internal connections and configuration of the meter housingelectrical connector130. As previously discussed, the meter housingelectrical connector130 is positioned to engage an electrical connector on themetering options module114 when themetering options module114 is coupled with themeter housing102.
• The meter housingelectrical connector130 may be internally coupled to abus160. Thebus160 may provide electrical connectivity from themeter housing connector130 tometering circuitry162 included inmeter100. InFIG. 14, thebus160 is coupled with an internal printed wiring/circuit board that is included in themetering circuitry162.
• In one example, thebus160 includes an intermediate printed circuit board that conducts the signals between themeter100 and themetering options module114. In other examples, thebus160 may be a plurality of wires, a serial bus, a universal asynchronous receiver transmitter (UART), or any other mechanism capable of communicating electrical signals. Thebus160 may provide a conduit for the signals between a processor, controller, field programmable gate array (FPGA) and/or CPU and other components included in the metering circuitry of themeter100 and a processor, controller, and/or central processing unit (CPU) and other components of themetering options module114. Thebus160 may terminate at one end in a multiple pin connector such as a 50 pin header (meter housing connector130) that is configured to engage themetering options module114. The other end of thebus160 may be terminated in ametering circuitry connector164, such as an edge connector. In one example, thebus160 may be coupled with an edge connector that is a 50 pin header on a CPU circuit board included in themetering circuitry162 of themeter100. Thebus160 therefore extends from themetering circuitry162, such as a main CPU board to themeter housing connector130 positioned in the first connector panel106aformed in themeter housing102 of themeter100.
• In one example, themetering circuitry162 of themeter100 includes the base circuitry for themeter100. The base circuitry may be that metering circuitry needed to perform revenue and power quality calculations. Themetering circuitry162 may include a CPU board having programmable processors, controllers, ASIC's, logic units, memory components gates, logic components and other devices configured to perform power metering functions, and enable features and functionality of themeter100. Themetering circuitry162 may include expansion ports or connectors (not shown) to allow functionality of themetering circuitry162 to be enhanced and/or expanded. At least a portion of themetering circuitry162, such as a CPU board, also may be removable from themeter100 and/or replaceable.
• FIG. 15 illustrates a perspective view from the rear of an example of themetering options module114, andFIG. 16 illustrates a rear view of an example of themetering options module114.FIG. 17 illustrates a perspective view from the front of an example of themetering options module114, andFIG. 18 illustrates a front view of an example of themetering options module114. As shown inFIGS. 15-18, themetering options module114 includes a moduleelectrical connector170 that is configured and positioned to engage with the meter housingelectrical connector130 on the surface of themeter100 when themetering options module114 is coupled with themeter housing102.
• Themetering options module114 is configured to provide optional and/or enhanced features and/or functionality for themeter100. For example, themetering options module114 may provide desired features and functionality for themeter100 beyond the base features of themeter100. Themetering options module114 additionally or alternatively may be designed to implement one or more discrete features that are useable by themeter100. As the needs for themeter100 change, themetering options module114 may be changed to update or otherwise change the functionality of themeter100.
• FIG. 19 is an example block diagram of the functionality of ameter100 that includes ametering options module114. InFIG. 19, a threephase power source202 includes a plurality ofconductors204. Theconductors204 may feed a load or a portion of a power system. The rack mountedmeter100 may be coupled with theconductors204 to receive and measure electrical parameters of electrical energy present in theconductors204. A plurality ofvoltage metering lines206 may be coupled with theconductors204 and themeter100 to provide voltage signals indicative of the frequency, magnitude, and phase of the voltage present on one or more of theconductors204. Themeter100 may also include a plurality of current transformers (CTs)208. Alternatively, theCTs208 may be separated away from themeter100. TheCTs208 may provide current signals on a plurality ofcurrent lines210. The current signals may be indicative of the magnitude of current flowing in the one or more of theconductors204.
• The voltage and current signals may be provided tometering circuitry212 included in themeter100. Within themetering circuitry212, the voltage and current signals may each be fed to afilter214. Thefilter214 may reduce noise, transients, harmonics and any other undesirable signal content that may be present on thevoltage lines206 and thecurrent lines208. In one example, thefilters214 may be low pass filters. In another example, thefilters214 may be unnecessary, and may be omitted. The filtered or unfiltered voltage and current signals may be modified by adjusting the magnitude and/or format with a respective voltage transducer/amplifier216 and a current transducer/amplifier218. In another example, the filtered or unfiltered current and voltage signals may be used directly without modification and the voltage transducer/amplifier and/or the current transducer/amplifier218 may be omitted. The filtered and modified voltage and current signals may be converted from analog to digital signals with an analog todigital converter220, and provided to aprocessor224.
• Theprocessor224 may include a digital signal processor (DSP)226, a field programmable gate array (FPGA)228, and a central processing unit (CPU)230. In other examples, one or more, or any combination of theDSP226, theFPGA228 and theCPU230 may be used to form theprocessor224. Theprocessor224 may direct the operation of themeter100. In addition, theprocessor224 may process the electrical parameters measured from theconductors204. Amemory234 may include aDSP memory236 and aCPU memory238. Thememory234 may include volatile and/or non-volatile memory. Thememory234 may store instructions executable by theprocessor224. In addition the memory may store power parameters, both measured and calculated by theprocessor224, user profiles, passwords, configurations, and/or any other data related to meter and power quality functionality.
• Themetering circuitry212 may also include a linefrequency measurement module242, apower supply244 and auser interface246. The linefrequency measurement module242 may be coupled with the voltage transducer/amplifier216 and theprocessor224. Based on the filtered and modified voltage signal, the linefrequency measurement module242 may generate a line frequency signal representative of the voltage present in theconductors204. The line frequency signal may be provided to theprocessor224. Thepower supply244 may be powered by theconductors204, an auxiliary supply of power, and/or a back up supply of power. Thepower supply244 may produce one or more voltages to power themetering circuitry212. In addition, thepower supply244 may supply power to themetering options module114. Theuser interface246 may include adisplay248 and akey pad250. In other examples, theuser interface246 may include any other device and/or mechanism that provides a man machine interface to themeter100 and/or other devices in communication with themeter100.
• Themetering circuitry212 may also include a printedcircuit board connection252. The printedcircuit board connection252 may provide an interface to the rackelectrical connectors128 as previously discussed, and be coupled with theprocessor224. In another example, the printedcircuit board connection252 may be external to themetering circuitry212.
• The removablemetering options module114 may also be coupled with themetering circuitry212. As previously discussed, themetering options module114 may include an electrical connector170 (FIG. 18) that is positioned to engage an electrical connector on a surface of the metering housing. Themetering options module114 may change the functionality of themetering circuitry212 and/or theprocessor224. InFIG. 19, themetering options module114 includes one or more of an input/output module260, acommunications module262, aprotective relay module264, and an accesskey module266.
• The input/output module260 may provide the capability to add additional inputs and/or outputs to themeter100. Accordingly, themetering options module114 may be configured to include circuitry and other hardware needed to provide such additional functionality.
• Themetering options module114 may also include a power supply backup functionality. For example, themetering options module114 may include a battery or other energy storage device that is a backup power supply. The backup power supply may be configured to supply power to themetering options module114. In addition, the backup power supply may be configured to supply power to themeter100. In the event of loss of power to themeter100, the backup power supply included in themetering options module114 may be automatically activated, switched, or otherwise enabled to provide a supply of power to themeter100 and themetering options module114. The backup power supply may power theentire meter100 andmetering options module114 when enabled to supply power.
• Alternatively, the backup power supply may power only some of the functionality of themeter100 ormetering options module114. For example, the backup power supply may provide power to only theprocessor224 to allow communication of a loss of power alarm, or to only that portion of themetering circuitry212 that will enable continued collection and storage of measured data. Any form of partial powering scheme that prolongs the life of the energy storage device included in the backup power supply may be employed to maintain a desired functionality of themeter100 and/ormetering options module114 upon loss of the main power source.
• Alternatively, or in addition, the backup power supply may include monitoring capability of the energy storage device included with the backup power supply. Themeter100 and/ormetering options module114 may include the capability to sequentially power down predetermined and/or pre-selected functionality within themeter100 and/or themetering options module114 at predetermined stages, or thresholds, of depletion of the energy storage device.
• The backup power supply may be accessible from outside themetering options module114 to allow replacement and/or testing of the backup power supply, as well as replacement and/or testing of the energy storage device included therewith. Replacement and/or testing of the backup power supply may be accomplished without disturbing any tamperproof seals included on themetering options module114 and/or themeter100.
• FIG. 20 is a block diagram illustrating the functionality of an example input/output module260 that includes asignal processing module302, alogic device304, and anoption key306. In other examples, additional or less hardware, modules and/or functionality may be included in the input/output module260. Thesignal processing module302 may provide digital and/or analog signal processing capability, which may include filtering, analog-to-digital conversion, signal isolation, signal conversion, etc.
• In the illustrated example, a digital input/output module310, and an analog input/output module312 are illustrated to represent processing, receipt and/or transmission of any form of digital and/or analog signals, such as pulse signals, 4-20 ma signals, 1-5 volt signals, and/or any other form of digital or analog signal. The digital input/output module310 and the analog input/output module312 may be coupled with the I/O ports150. The I/O ports150 may include connectors, terminals strips and/or any other form of coupling mechanism capable of providing a signal interface to devices external to themetering options module114. The digital input/output module310 and the analog input/output module312 also may be coupled with thelogic device304.
• Thelogic device304 may be any mechanism or device capable of providing an interface between the digital input/output module310 and the analog input/output module312 and the metering circuitry212 (FIG. 19). In one example, thelogic device304 is a programmable logic device that is programmed to operate as a multiplexer. In other examples, the logic device may be a buffer, a UART, etc. Thelogic device304 may be configured to communicate I/O signals between the digital input/output module310 or the analog input/output module312 and theelectrical connector170 mounted on a surface of the metering options module.
• Theoption key306 also may be coupled with theelectrical connector170. Theoption key306 may be in communication with the processor224 (FIG. 19) via theelectrical connector170. Theoption key306 may identify to theprocessor224 that the metering options module includes the I/O functionality. Thus, when the metering options module is coupled with the electrical connector130 (FIG. 5) on the meter housing102 (FIG. 1), the processor is able to determine what functionality has been added/changed. In one example, theoption key306 may include a plurality of option resistors which are configured to identify the additional functionality added by the metering options module. In other examples, a memory, a dip switch, or any other mechanism or device may be used to identify the metering options module to the processor. The option key may also define the I/O ports150, ranges of the I/O signals present on the I/O ports150, and/or provide any other information related to the processor224 (FIG. 19) cooperatively operating with the metering options module.
• Theelectrical connector170 may also provide one ormore supply voltages314. Thesupply voltages314 may be provided from the power supply244 (FIG. 19) included in the metering circuitry212 (FIG. 19) to power devices, providing wetting voltages, etc. In addition, thesupply voltage314 may provide power to abackup power supply316 included in the metering options module when the power supply244 (FIG. 19) is being powered. Thebackup power supply316 may include an energy storage device, such as a battery, that is maintained in a fully charged state by thesupply voltage314. The backup power supply may include a voltage sensing device to sense the voltage levels and quality of thesupply voltage314. Upon loss of power to thesupply voltage314, or degradation of the quality of power supplied to thesupply voltage316 below a predetermined level, thebackup power supply316 may be enabled to supply backup power to themeter100 and themetering options module114. As previously discuss, the backup power supply may energize all or portions of themeter100 and/or themetering options module114.
• Theelectrical connector170 may also be coupled with the digital input/output module310 and/or the analog input/output module312 via one or more dedicated signal lines318. The dedicated signals line(s)318 may also couple the digital input/output module310 and/or the analog input/output module312 to the I/O ports150. The dedicated signal line(s)318 may transmit signals directly between the I/O ports150, the digital input/output module310 and/or the analog input/output module312, and the metering circuitry212 (FIG. 19) without processing the signals in the respective digital input/output module310 and the analog input/output module312 or through thelogic device304.
• For example, the digital input/output module310 may selectively operate in three modes to process one or more input signals on one or more respective channels. The three modes may be operated simultaneously, and/or in any combination within the digital input/output module310. A first mode may be a pulse mode, and a second mode may be a KYZ mode. In the first and second modes the digital input/output module310 may operate to detect a DC level of a signal being received as an input. The input signal may be digitized by the digital input/output module310, and then further processing within the digital input/output module310 may occur based on the DC levels that were sampled.
• A third mode may be an “AC” mode in which time varying input signals are received and processed. In the third mode, the digital input/output module310 may operate to provide received AC input signal(s) to the metering circuitry212 (FIG. 19). Themetering circuitry212 may rectify the AC input signal(s) and then digitize the input signal(s) for further processing. The signal(s) may be further processed with themetering circuitry212 based on the sampling frequency applied during digitization. If an input signal is within a predetermined frequency range on a given channel, the status of that channel may be indicated as “ACTIVE” by themetering circuitry212.
• The AC input signals may be provided from the I/O ports150 on the dedicated signal line(s)318 to pass through the digital input/output module310 without processing to themetering circuitry212. The AC input signals may be rectified, digitized, and further processed using code, such as firmware stored in memory234 (FIG. 19). The firmware may be executable by the processor224 (FIG. 19) included in themetering circuitry212. For example, a sine wave input signal may be rectified, and a peak of each half cycle may be detected during sampling. In one example, AC input signals passed through the digital input/output module310 may be timestamped with a high accuracy timestamp similar to other DC digital inputs, before being passed to themetering circuitry212 to be processed. Because the timestamp can be implemented in the digital input/output module310, and the processing of the AC input signal may occur with firmware in the metering circuitry, both DC and AC digital inputs may be processed using the same hardware, namely, the digital input/output module310. In addition, since the AC input signals are processed with firmware in themetering circuitry212, processing of the AC input signals may be flexibly selected and varied by updating and/or changing the configuration of the code included in the firmware.
• Implementation of the third mode (AC input detection) by the metering circuitry212 (FIG. 19) may occur in firmware to also allow AC input detection functionality to be enabled without compromising the speed at which the digital input/output module310 can detect signals in the first (“Pulse”) mode or the second (“KYZ”) mode. Alternatively, the AC input signals may be processed within the digital input/output module310. However, implementation of processing of the AC input signals in the digital input/output module310, may use an RC-filter to convert the AC waveform into a DC signal that can be read by themetering circuitry212, which may limit the pulse rate that can be resolved in first (“Pulse”) mode and/or the second (“KYZ”) mode.
• Firmware implementation of the AC input processing in the third mode may also allow flexibility in adjusting a frequency range to be sensed by themetering circuitry212 by simply changing the code within the firmware. In one example, the frequency range of sensing may be set to a predetermined range of about 5 Hz to about 210 Hz. Adjustment of the frequency range may be implemented with a firmware upgrade, or the frequency may be a user selectable parameter when themeter100 is operational in the field. Alternatively, if AC input processing occurs with hardware within the digital input/output module310, a low-end frequency limit may be set.
• Thecommunications module262 may provide expanded/additional functionality related to communication with other devices external to themeter100.FIG. 21 is a block diagram illustrating the functionality of anexample communications module262 that includes acommunication interface module402 and an optionkey module404. The examplecommunication interface module402 includes a first interface that is a first serial interface, such as an RS232/RS485 interface406, a second interface that is a second serial interface, such as aRS485 interface408, a third interface that is amodem interface410, and fourth interface that is anetwork interface412. In other examples, fewer or additional interfaces, such as proprietary interfaces, may be included in thecommunication interface module402.
• The first and secondserial interfaces402 and404 may each include an RS485 communication interface. Themodem interface406 may be any communications device that converts a signal from one form to another form that is suitable for transmission over communication circuits, such as, from digital to analog and then from analog to digital signals. Themodem interface406 may be a wired or a wireless device that uses anantenna314. Theantenna314 may be included in thecommunications module262, or may be externally coupled with themetering options module114 via the I/O ports150. Thenetwork interface412 may be a wired or wireless interface to any form of LAN, WAN, etc. form of network. For wireless communication, thenetwork interface412 may use theantenna414. Thenetwork interface412 may include Ethernet communications, GPS time sync communication capabilities, wireless devices communications (e.g., 802.11 and the like), wireless mesh networks, Zigbee, Wi-Fi, and/or any other network communication standard and/or protocol. The Ethernet communications may be 10 BaseT Ethernet, 10 BaseFL Ethernet and/or any other Ethernet protocol. In addition, thenetwork interface412 may support proprietary protocols.
• Each of the interfaces406-412 may establish independent or separate communications with a device external to themeter100. Thus, the metering options module may enable multiple instances of communications with themeter100. The I/O ports150 may be internally coupled directly or indirectly through electrical, electronic and/or optical components and/or hardware, software, and firmware components included in thecommunication interface module402 to theelectrical connector170. As previously described, theelectrical connector170 may be coupled to the meter housingelectrical connector130 on themeter100 when themetering options module114 is installed on themeter100. Accordingly, the metering circuitry212 (FIG. 19) may be enabled to communicate with external devices through the I/O ports150 when the metering options module is installed on themeter100.
• Within thecommunication module262, the I/O ports150 may be communication ports that include optical communications ports (ST) that enable coupling and external communication using optical fiber, RJ11 (such as for modem communication) and RJ45 jacks (such as for Ethernet communication), Phoenix connectors (such as for RS485 communication), DB9 connectors (such as for RS232 communication), RCA jacks, and/or any other type of communication connector hardware. The electronic and/or optical components of theinterface module402 coupled with the I/O ports150 may include, switches, gates, processor, CPU's, application specific integrated circuits (ASIC's), controllers, diodes, capacitors, inductors, resistors, bridges and other electronic and electrical devices used in communications circuits.
• Referring toFIGS. 19 and 21, themetering circuitry212 also may be configured to assign a communications protocol to an I/O port150 in themetering options module114 independent of the type of hardware connector included with the port, and independent of the communications protocol assigned toother communications ports150. For example, themeter100 may be configured to have first and second I/O ports150 included in themetering options module114 assigned to communicate with other devices. Each of the first and second I/O ports150 may communicate independently of the other, and each may use a device language message specification (DLMS) protocol. In another example, each I/O port150 may be assigned a different communications protocol. For example, a first communication port may be assigned to communicate with other devices using DLMS, a second communication port may be assigned to communicate using Modbus® and a third communication port may be assigned to communicate with a device using ION® communications protocol.
• The communications protocol may be assigned to a communication port, or a communication port may be assigned to a communications protocol. Assignment may be performed by selecting an appropriate setting(s) on the options menu presented on thedisplay118, by factory settings, and/or by a controller in communication with themeter100. An I/O port150 also may be configured to communicate using two or more communications protocols substantially simultaneously. That is, for example, two communication protocols may co-exist at thesame communication port150. The communications protocols for thecommunication ports150 may be changed, modified, updated and/or reprogrammed.
• The communication capabilities available to themetering circuitry212 included in themeter100 from themetering options module114 may be almost unlimited. Themetering options module114 may be configured to provide an Ethernet communications for the rack-mountedmeter100. The Ethernet communications may include 10 BaseT and/or 10 BaseFL. The rack mountedmeter100 may also be configured to communicate over an open, distributed communications network with a web server or other devices on the network. Themeter100, using thecommunications module262, also may be configured to provide web server functions or functionality to serve other devices on the network. Thecommunication module262 may also provide for communication functionality using optical fiber, multiple serial ports and/or any combination thereof. Any combination of hardware related to communications is possible within thecommunication module262. Thecommunication module262 also may be configured to provide a SCADA polling system.
• Theinterface module402 may be coupled with themetering circuitry212 via theelectrical connector170. Alternatively, or in addition, theinterface module402 may wirelessly communicate with themetering circuitry212. Thepower supply244 may provide power to asupply voltage420 via theelectrical connector170. Thesupply voltage420 may provide power to theinterface module402, the I/O ports150 and/or any other power consuming device in thecommunication module262. In addition, thesupply voltage420 may supply power to abackup power supply422 included in themetering options module114. Thebackup power supply422 may supply power to themeter100 and/or themetering options module114 in the event of degradation and/or loss ofsupply voltage420, as similarly discussed with reference to thebackup power supply316 ofFIG. 20. Theoption key404 may provide an indication to themetering circuitry212 that thecommunication module262 is present. In addition, theoption key404 may define the signals to be expected on the I/O ports150.
• Theprotective relay module264 may be any form of hardware, circuitry, software and/or firmware capable of providing protection for at least a portion of themeter100. For example, theprotective relay module264 may provide fusing or other circuit interrupting capability for at least portions of themeter100. One or more analog signals may be routed through theprotective relay module264 to protect themeter100. Since the metering options module is readily removable, without disturbing any tamper-proof seals on themeter100, theprotective relay module264 may be readily replaced if an event causes the protective relay functionality, such as a fuse functionality, to occur.
• In addition, or alternatively, theprotective relay module264 may include power quality event tracking capability. For example, theprotective relay module264 may be equipped with functionality that interrupts potentially damaging signals from reaching themetering circuitry212, while continuing to record the event and/or disturbance that created the signals. In this scenario, theprotective relay module264 may include more robust circuitry and hardware capable of withstanding such an event without damage. Alternatively, theprotective relay module264 may include functionality to capture events from start to finish that otherwise interrupt the receipt and processing of electrical parameters by themetering circuitry212, such as when an event causes damage to themetering circuitry212. Signals with potential for such events may be routed through theprotective relay module264, or be provided as a parallel feed to theprotective relay module264.
• The accesskey module266 may enable additional functionality already present in themetering circuitry212 by providing some form of authorization. The authorization may be hardware and/or software based. Enabling functionality may include for example, additional power parameter processing or power quality analysis functionality. Other examples include increased sample rates, improved hardware functionality, enhanced user interface, such as additional buttons and/or controls, improved/expanded graphics capability, and/or any other operational functionality within ameter100 that is determined to be an optional feature.
• FIG. 22 is a block diagram of an example accesskey module266 that includes ahardware authorization502 and asoftware authorization504. The accesskey module266 may also include asupply voltage518 being supplied power from the power supply244 (FIG. 19) via theelectrical connector170. Thesupply voltage518 may provide power to the accesskey module266 and/or themetering options module114. In addition, thesupply voltage518 may supply power to abackup power supply520 included in themetering options module114. Thebackup power supply520 may supply power to themeter100 and/or themetering options module114 in the event of degradation or loss of thesupply power518, similar to thebackup power supply316 discussed with reference toFIG. 20.
• Thehardware authorization502 may represent a first layer of authorization that includes anoption key508, and an accesskey code510. Theoption key508 may be coupled with themetering circuitry212 via theelectrical connector170 to indicate that the accesskey module266 is present. In addition, theoption key508 may provide configuration information, authorization functionality in the accesskey module266 to be verified, or any other information related to authorization of the additional functionality. The accesskey module266 may be dip switches, resistors, and/or any other hardware based keying functionality.
• Thesoftware authorization504 may represent a second layer of authorization that can include acommunication circuitry512, aprocessor514 and amemory516. Thecommunication circuitry512 may be a UART, a buffer or any other device or mechanism for enabling communication between theprocessor514 and the metering circuitry212 (FIG. 19). In another example, direct communication between theprocessor514 and the metering circuitry212 (FIG. 19) may be possible, and thecommunication circuitry512 may be omitted. Theprocessor514 may direct communication with themetering circuitry212 and also access to thememory516. Theprocessor514 may include firmware that contains an access key code that is provided to themetering circuitry212 upon installation of the metering option module. The access key code may unpack, enable, and/or otherwise turn on additional features and/or functionality in themeter100.
• Theprocessor514 may also have the capability to track and maintain a database ofmeters100 upon which the accesskey module266 has been installed to activate additional functionality. For example, theprocessor514 may provide a predetermined number of functionality activations, and function as a counter to track the number of activations by storing them in thememory516. Alternatively, or in addition, theprocessor514 may perform verification that the previously non-activated portion of the software of themetering circuitry212 is an up to date version and update accordingly. Thememory516 may also include upgrade software that is downloadable to themetering circuitry212 by theprocessor514 to upgrade the base functionality of themeter100. In other examples, either thehardware authorization502 or thesoftware authorization504 may be separately implemented in a stand alone capacity to provide authorization and verification of the mounting and use of themetering options module114 on themeter100.
• In another example, thememory516 may include software to affect the changed functionality of themetering circuitry212. Thus, when themetering options module414 is installed, theprocessor514 may download the software into themetering circuitry212. In still other examples, thememory516 could include patches, fixes and revisions to the existing base functionality included in themetering circuitry212. The revisions could be downloaded by theprocessor514 when the metering options module is installed. Alternatively, the revisions/updates/improvements could be maintained in thememory516 and executed by the metering circuitry directly from thememory516.
• The functionality of the previously described modules260-266, as well as any other functionality, may be mixed or otherwise combined in themetering options module414. In addition, themetering options module414 may provide standalone functionality, such as monitoring the operation of themetering circuitry212 and providing an indication when an error or fault occurs within themetering circuitry212.
• Referring again toFIGS. 15-18, theelectrical connector170 on a surface of themetering options module114 may engage with theconnector130 on a surface of themeter house102 to change the operational functionality, such as the I/O functionality and/or the communications functionality, of themeter100. Ahousing182 of themetering options module114 may be a substantially rectangular box, or rectangular parallelepiped that is dimensioned to fit within the shelf dimensions or dimensional envelop of themeter100, and/or allow themeter100 to fit within a bay of an equipment rack when themetering options module114 is coupled thereto.
• Themetering options module114 may include one ormore flanges184. Theflange184 may be fixedly coupled and/or form a part of thehousing182. In the examplemetering option module114 illustrated inFIGS. 14-18, thehousing182 includes afirst surface186 and asecond surface188 that is opposite thefirst surface186. Thefirst surface186 may be positioned to be substantially flush with the first portion108aof the two tiered surface108 (FIG. 1) when themetering options module114 is coupled with themeter100. Thesecond surface188 may be contiguous with the second portion108bof the two-tiered surface108 (FIG. 1) when themetering options module114 is coupled with themeter100.
• Theflange184 may be positioned substantially parallel with thesecond surface188, and substantially perpendicular with the second connector panel106b(FIG. 4) of themeter housing102. Theflange184 may be formed to include at least oneaperture190. Theapertures190 may be aligned with thefastener117 on the meter housing102 (FIG. 2) when themetering option module114 is mounted on themeter house102. Theflange184 may also include one ormore tabs124. The tab(s)124 may be formed to be substantially perpendicular to theflange184 and substantially parallel to a surface of themeter housing102, such as the second connector panel106b(FIG. 4). Accordingly, when themetering options module114 is installed on the surface of the metering housing102 (FIG. 4), thetab124 may contiguously align with a portion of the second connector panel106b(FIG. 4).
• Thetab124 may include acoupling aperture194. Thecoupling aperture194 may be alignable with the ground lug126 (FIG. 4) on themeter housing102 when themetering options module114 is coupled with themeter housing102. Themetering options module114 may also include at least onealignment aperture196. Thealignment apertures196 may be formed to accommodate the alignment pins131 on the first connector panel106a(FIG. 5) when themetering options module114 is coupled with themeter housing102.
• Themetering options module114 may be grounded via theground lug126 as previously described. Themetering options module114 may also include a lug, a lance, a cleat, or some other feature to be used in conjunction with a tamper-proof seal to couple themetering options module114 to themeter100. Thehousing182 of themetering options module114 may also be separately sealable with a tamper proof seal, such as a revenue or verification seal that is separate from the tamper proof seal, such as a verification seal, of themeter100.
• FIG. 23 illustrates a top view of anexample meter100 mounted in abay171 of anequipment rack assembly172.FIG. 24 illustrates a perspective front view of an example of themeter100 mounted in thebay171 of theequipment rack assembly172.FIG. 25 illustrates a perspective rear view of an example of themeter100 mounted in thebay171 of theequipment rack assembly172. InFIGS. 23-25, theequipment rack assembly172 may be a 48.3 cm equipment rack designed in accordance with the requirements set forth by DIN43862. Themeter100 with themetering options module114 affixed thereto may fit within the dimensions of a standard 48.3 cm equipment rack. Themeter100 may plug into a bayelectrical connector174, such as an Essailec connector, located in a determined position, such as at the back of theequipment rack assembly172. Themeter100 may be mounted to therack assembly172, with or without themetering options module114.
• Themeter100 may be easily or readily removed or mounted to theequipment rack assembly172. When inserted, the rackelectrical connector128 on the second connector panel106bof the meter100 (FIG. 6) may engage the bayelectrical connector174 in therack assembly172. When theconnectors128 and174 are engaged, themeter100 may be powered by one of the connections, and receive signals to allow themeter100 to perform revenue metering as well as power quality monitoring for an electrical circuit, such as multi-phase high voltage power supplied over a conductor to a dynamic load circuit.
• The metering circuitry included in themeter100 may log a time that themeter100 is installed in theequipment rack assembly172, as well as a time that themeter100 is removed from theequipment rack assembly172. The log may be accessed using the user interface of the control panel116 (FIG. 3) of themeter100, and/or through one of the communications ports, such as a communication port150 (FIG. 14) provided by themetering options module114. The metering circuitry may be configured to detect whether themeter100 is installed in theequipment rack172 using an analog or digital I/O connection for themeter100. When connection or disconnection of any of the I/O between themeter100 and theequipment rack172 is detected, the corresponding event may be time stamped and stored in memory in an event log.
• The metering circuitry of themeter100 also may determine whether removal of themeter100 is appropriate and set an alarm or indicator when an attempt to remove themeter100 from therack assembly172 is made when removal is inappropriate. For example, the metering circuitry may detect that themeter100 is being removed, such as due to a disengagement/disconnection of therack connector128 and thebay connector174. In response to the detection, themeter100 may automatically set a visual and/or audible alarm(s) indicating that disengagement/disconnection is inappropriate. Themeter100 also may include a mechanical interlock that actuates to latch or engage therack assembly172 after themeter100 is installed in thebay171. The interlock may be released only when themeter100 is in a state in which themeter100 may be removed, as determined by the metering circuitry based on the I/O received by themeter100.
• In one example configuration, a secondary electrical connector (not shown), also or alternatively, may be used on theequipment rack assembly172. The secondary connector may be configured to be positioned between thebay connector174 and the rackelectrical connector128. Alternatively, the secondary connector may be used in place of thebay connector172 or the rackelectrical connector128. The secondary connector may provide a make-before-break functionality to short those inputs that should be shorted, such as current transformer (CT) inputs, and open those inputs that should be opened, such as potential transformer (PT) inputs. Accordingly, with the secondary connector, the rack-mountedmeter100 may be removed and installed in thebay171 while the conductor themeter100 is monitoring is live or under power. The secondary connector may operate in reverse when themeter100 is installed in thebay171.
• The metering circuitry of themeter100 also may be configured to approximate power usage during a reset of themeter100, such as after a power failure. Since themeter100 includes a clock, themeter100 may determine when themeter100 last read energy usage and how long themeter100 may have been de-energized. For example, if themeter100 is removed from theequipment rack172, or is otherwise de-energized or removed from service, themeter100 can record the event. When themeter100 is reset and powered back up, the metering circuitry can compare the time that themeter100 last measure power parameters to the present time to calculate an amount of time that themeter100 was powered down or otherwise out of service. The metering circuitry can also review power usage before it was taken out of service to interpolate or approximate an amount of power usage while themeter100 was out of service. The metering circuitry may also record the approximation of the amount of power usage, and mark or flag the event for future review.
• The configuration of the rack-mountedmeter100 with the externally mountedmetering options module114 provides a capability to incorporate features and functionality of themeter100 in a separable module having its own housing. Themetering options module114 may be field replaceable without disturbing a tamper proof seal, such as a verification or utility seal included on themeter100. The replaceablemetering options module114 may provide additional communications functionality and connections, input/output functionality and connections, and/or any other functionality and connections for themeter100. Communications connectors and/or input/output connectors may be directly included on the housing of themetering options module114, rather than on the connector panel of themeter100. As communications or other input/output needs change, themetering options module114 may be changed or replaced accordingly, without requiring modification to themeter100 and/or disturbance of the tamper proof seals.
• Themetering options module114 that is removably installed flush with the first portion108aof the two-tiered surface108 of themeter100 enables changing of the functionality of themeter100 without disturbing the seal on themeter100. Themetering options module114 may be mounted outside themeter housing102 and may be changed without having to modify or open themeter100. Without themetering options module114, a field retrofit of the communication or input/output connectors may not be possible, especially if tamper-proof seals were disturbed. Therefore, a meter configuration having a separablemetering options module114 offers great flexibility in providing various alternatives in future designs, without requiring a redesign or complicated retrofitting of themeter100. Themetering options module114 may be used to expand operation of the meter for options other than communication or input/outputs. For example, themetering options module114 may be changed out to change or provide additional calculated power parameters, perform additional power quality monitoring, etc.
• When racked into thebay171 of theequipment rack assembly172, the rack-mountedmeter100 may receive power for operating as well as signals corresponding to electrical parameters of one or more conductors feeding a circuit or load that is to be monitored. In one example, the metering circuitry included in the rack-mountedmeter100 may be configured to measure and/or approximate a voltage that may appear on a grounded line by a comparison of reference voltage V_refthat is connected to a neutral line of the circuit or load being monitored with an internal dc voltage. Ordinarily the reference voltage V_refshould be OV. However, the reference voltage V_refmay vary in different places in a building. The reference voltage V_refmay vary with current and resistance in the neutral line. The reference voltage V_refcan also indicate 3^rdharmonics, power surges, problems with the power system, possible wiring problems, and the like. In one example, a ground voltage V_Gmay be calculated, by comparing the reference voltage V_refto an internal dc reference voltage V_biasthat is referenced to earth ground. The internal dc reference voltage V_biasmay be supplied by a constant voltage supply. Fluctuations in the ground voltage to neutral may be determined from V_bias. An existing spare or unused op-amp included in the metering circuitry of themeter100 can be biased with a resistor circuit to provide the reference voltage V_refat an output based on the comparison to the V_biasvoltage. Using the spare op-amp utilizes existing circuitry and reduces a number of terminals or inputs to the meter.
• The input signals provided to the rack-mountedmeter100 may be scaled based on the strength of the signal. The signals from theequipment rack assembly172 often vary over a wide range of voltages. The metering circuitry included in themeter100 may detect the strength of the input signal(s) and process the signals through a multi-gain stage circuit before the signals are further processed. The metering circuitry included in themeter100 may be configured to monitor the amplitude of an input signal. Based on the amplitude, the metering circuitry may adjust the gain of the input signal to provide an input signal for themeter100 having an appropriate signal to noise ratio. The metering circuitry may select an appropriate scaling based on the amplitude of the input signal. Accordingly, themeter100 may be used over a wide dynamic range of input signals.
• When the signals are received, the metering circuitry may sample the signal to provide a sampled or digital equivalent signal representing the analog signal. The signals may be sampled at a sampling frequency that is determined based on the analog frequency of the input signal. That is, the rack-mountedmeter100 has a sampling clock that may be adjusted according to the frequency of the power system being monitored.
• The sampled signal is processed using metering circuitry that includes a controller, a logic unit, a processor, an ASIC and/or combinations thereof configured to determine electrical parameters of the circuit based on the sampled signals. The sampled signals may be processed according to Fast Fourier Data Processing techniques. The use of Fourier transforms to process the signals solves issues of high computational intensity due to continuous harmonic analysis on the sampled input signals. The input signals may be continuously sampled and averaged with the metering circuitry. The averaged signals may be converted or transformed to the Frequency domain with the metering circuitry. A frequency average may be determined by averaging in the time domain and transforming the average once. The Fast Fourier data processing technique translates/manipulates the data to Radix 2 numbers to process the data using Fourier transforms.
• Themeter100 may display compliance of a monitored conductor to multiple power quality standards. The compliance may be displayed on thescreen118, and updated as service complies or fails to comply with a power quality standard. Examples of a power quality standard to which compliance may be displayed include EN5160, EEC 61000-4-30. The compliance display may be updated in real time.
• Various embodiments of a rack-mounted power meter having an externally mounted removable metering options module have been described and illustrated. However, the description and illustrations are by way of example only. Many more embodiments and implementations are possible within the scope of this invention and will be apparent to those of ordinary skill in the art. The various embodiments are not limited to the described environments, and can be applied to a wide variety of activities.
• It is intended in the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention. Therefore, the invention is not limited to the specific details, representative embodiments, and illustrated examples in this description. Accordingly, the invention is not to be restricted except as necessitated by the accompanying claims and their equivalents.

Claims (33)

1. A power meter configured to measure electrical parameters of electrical energy present in a conductor, the power meter comprising:

a meter housing configured to be rack mounted in a bay of an equipment rack; and

a metering options module configured to be removably mounted on an externally accessible surface of the meter housing to be within the dimensions of the bay,

the meter housing comprising a first electrical connector, and the metering options module comprising a second electrical connector, the first electrical connector configured to be engaged with the second electrical connector only when the metering options module is removably mounted on the meter housing.

2. The power meter ofclaim 1, comprising a first rack electrical connector positioned on an external surface of the meter housing, the first rack electrical connector positioned to engage a second rack electrical connector in the equipment rack when the meter housing is installed in the bay.

3. The power meter ofclaim 1, wherein the first electrical connector is mounted on an external surface of the meter housing, and the second electrical connector is mounted on an external surface of the metering options module.

4. The power meter ofclaim 3, wherein the external surface of the meter housing is positioned proximate the external surface of the metering options module so that the first electrical connector and the second electrical connector engage when the metering options module is removably mounted on the meter housing.

5. The power meter ofclaim 1, further comprising a tamper proof seal coupled with the meter housing and configured to indicate when the meter housing has been opened, wherein the metering options module is removably mountable on the meter housing without disturbance of the tamper proof seal.

6. The power meter ofclaim 1, wherein the externally accessible surface of the meter housing comprises a first portion and a second portion, the first portion formed as a slot to accommodate the metering options module.

7. The power meter ofclaim 6, wherein the first portion is recessed with respect to the second portion, and a first planar surface of the metering options module is substantially contiguously aligned with a planar surface of the first portion when the metering options module is mounted, and a second planar surface of the metering options module is in substantially the same plane with a planar surface of the second portion of the meter housing.

8. The power meter ofclaim 1, wherein the metering option module comprises a tab configured to be coupled with the meter housing, wherein a ground lug included on the meter housing is configured to ground the metering options module and fixedly mount the metering options module on the meter housing via the tab.

9. The power meter ofclaim 1, wherein the metering options module comprises a flange configured to be substantially contiguous with the meter housing when the metering options module is mounted on the meter housing, the flange further configured to be coupled with the meter housing by a fastener.

10. The power meter ofclaim 1, wherein the metering options module further comprises an options rack electrical connector configured and positioned on the metering options module to engage an options rack electrical connector included in the equipment rack when the meter housing with the metering options module removably mounted thereto is rack mounted in the bay of the equipment rack.

11. A power meter configured to measure electrical parameters of electrical energy present in a conductor, the power meter comprising:

a meter housing dimensioned to be mounted in a bay of an equipment rack, the meter housing having a first electrical connector positioned on a surface of the meter housing to engage a second electrical connector positioned in the equipment rack when the meter housing is mounted in the bay;

metering circuitry disposed in the meter housing that is configured to receive one or more electrical parameters via the second electrical connector, the metering circuitry operable to measure and process one or more electrical parameters;

a tamper proof seal coupled with the meter housing and configured to indicate the occurrence of access to at least one of the meter housing or the metering circuitry, or a combination thereof;

a slot formed with the meter housing, the slot configured to receive a metering options module without disturbance of the tamper proof seal; and

a third electrical connector disposed in the slot and electrically connected with the metering circuitry, the third electrical connector configured to be coupled with the metering options module to change the functionality of the metering circuitry.

12. The power meter ofclaim 11, wherein the metering options module is positionable in the slot to extend outwardly no further than about flush with an outermost external dimension of an externally accessible surface of the meter housing.

13. The power meter ofclaim 11, wherein the third electrical connector is mounted in an externally accessible surface of the meter housing.

14. The power meter ofclaim 11, further comprising a bus operable to couple the third electrical connector with the metering circuitry.

15. The power meter ofclaim 14, wherein the bus is a printed circuit board that is coupled with an edge connector included in the metering circuitry.

16. The power meter ofclaim 11, further comprising a removable cover formed to cover an opening to the slot.

17. The power meter ofclaim 11, wherein the first and second electrical connectors each comprise a pluggable panel mount connector.

18. A power meter configured to measure electrical parameters of electrical energy present in a conductor, the power meter comprising:

a meter housing dimensioned to be mounted in a bay of an equipment rack;

a processor disposed in the meter housing and operable to process measured electrical parameters to perform revenue metering and power quality metering;

a tamper proof seal coupled with an external surface of the meter housing and positioned to indicate the occurrence of access to the meter housing;

a first electrical connector mounted on an external surface of the meter housing, the first electrical connector coupled with the processor and configured to engage an electrical connector in the equipment rack; and

a second electrical connector mounted on a surface of the meter housing, the second electrical connector coupled with the processor and configured to engage an electrical connector mounted on a surface of a metering options module, the metering options module mountable on the meter housing without disturbance of the tamper proof seal, to change a functionality of the processor.

19. The power meter ofclaim 18, wherein the metering options module includes an input/output module configured to increase the input/output capability of the processor.

20. The power meter ofclaim 18, wherein the metering options module includes a communications module configured to increase the communication functionality of the processor.

21. The power meter ofclaim 18, wherein the metering options module includes at least one of a hardware authorization or a software authorization each configured to enable additional functionality already existing, but previously disabled, in the processor when sensed by the processor.

22. The power meter ofclaim 18, wherein the metering options module includes an option key, the option key readable by the processor to indicate to the processor the functionality change providable by the removable options module.

23. The power meter ofclaim 18, wherein the second electrical connector is operable to supply power to the metering options module only when the metering options module is mounted on the meter housing.

24. A power meter configured to measure electrical parameters of electrical energy present in a conductor, the power meter comprising:

a metering options module configured to be removably coupled to a surface of a meter housing; and

an electrical connector positioned on a surface of the metering options module, the electrical connector positioned to engage an electrical connector included on a surface of the meter housing when the metering options module is coupled to the surface of the meter housing;

wherein an external housing of the metering options module is formed to be mounted external to the surface of the meter housing and to be substantially within an outermost dimension of the meter housing.

25. The power meter ofclaim 24, further comprising a flange coupled with the metering options module, wherein the flange is configured to fixedly couple the metering options module to the surface of the meter housing.

26. The power meter ofclaim 24, wherein the combination of the metering options module removably coupled to the meter housing is dimensioned and configured to be rack mounted in a bay of an equipment rack.

27. The power meter ofclaim 26, wherein the electrical connector is positioned on a first surface of the metering options module and an options rack electrical connector is positioned on a second surface of the metering options module, wherein the options rack electrical connector is positioned to engage an options rack electrical connector positioned in the equipment rack when the metering housing, with the metering options module removably coupled thereto is positioned in the bay of the equipment rack.

28. The power meter ofclaim 24, wherein the electrical connector is positioned on a first surface of the metering options module and a communications connector is positioned on a second surface of the metering options module.

29. The power meter ofclaim 24, wherein the electrical connector is positioned on a first surface of the metering options module and an input/output connector is positioned on a second surface of the metering options module.

30. The power meter ofclaim 24, wherein the metering options module is configured with functionality that is removably combinable with functionality present in metering circuitry included within the meter housing.

31. The power meter ofclaim 24, wherein the metering options module is configured with access key functionality, the access key functionality operable to enable pre-existing functionality present in metering circuitry included within the meter housing.

32. The power meter ofclaim 24, wherein the metering options module is configured with protective relay functionality.

33. The power meter ofclaim 24, wherein the metering options module is formed to include alignment apertures, the alignment apertures are configured to engage corresponding alignment pins included on the meter housing.

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