CA2014915A1 - Modular construction for electronic energy meter - Google Patents

Abstract

ABSTRACT OF INVENTION

A modular versatile electronic energy meter is provided with current voltage and register modules which may be selected and readily interconnected along with a selected output circuit board and including a plurality of features which may be customized late in the manufacturing cycle or after manufacture, including jumpers adapted to be selectively cut and attachable switch restrictors.
Reduction and standardization of components and uncomplex interconnections are provided, along with means to assure proper assembly and testing of the modular meter.

Description

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ME-2~8 MODULAR CONSTRUCTXON FOR ELECTRONIC ENERGY METER

BACKGROUND ON INVENTION
The present invention r~lates to electric energy meters, and particularly electronic electric energy meters and the construction of such meters.
Wlth the use of Plectronics in electric energy meters, including microprocessors and digital signal processing, the capabilities and potential for increased featureq, output information, and built-in te~ting has been greatly expanded. It is possible to of~er and meet customer requirements for a large number of optional features and ~unctions lncluding self-check test functions, demand metering with versatility in setting and displaying demand periods, and other functions and modes of lS operation. However, with such increased versatllity comas greatly increased problems of manufacturing, stocking and repairing a large numbe~ of different energy meters. In addit~on, meters must be capable of meetlng customer requirements as to voltage rating, class ~or ~urrent rating), and form. The form ls typlcally an application description according to a~ ~m~rican National St~ndards Institute (ANSI) standard such as C12.10-1978.
The result is literally hundreds of potentially dlfferent meters each differin.g in combinations of features and attributes.
This has led to considerable concern and interest in simplifying ' ' .

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ll-ME-238 the manufacture of electric energy meters, which, would decrease the cost of manufacture and assembly, minimize the number of parts required and thus lower thb cost and problems associated with stocking spare parts and providing repairs. At the same time it is necessary to provide a versatile energy meter construction which can readily be differently configured to meet a large variety o~
customer re~llrements. In order to maximize the use of mass production techniques and minimize the amount of manpower required for such customized energy meters, the need exists for improved energy meter designs and constructlon arrangements which meet the above ob~ectives, whlle at the same time provlding a basic Pnergy meter design which may be manufactured and stocked, and subsequently readily customized to meet a large number of specific customer requirements.
OBJECTS AND SUMMARY (:)F INVENTION
It is an ob~ect of the present inventlon to provlde a~
improved electronic energy meter which is slmpllfled and less costly to manufacture, yet which provldes increa~ed versatility in its features and applicatlons.
It ls another ob~ect of the present lnventlon to provide an slectronic energy meter with increased interchangeability of components to provide different functions and features to meet a lar~e number of customer specifications.

ll-M~-238 It is yet another ob~ect of the present invention to provide an electronic eneryy meter with optimized interchangeability of components while simplifying el.ectrical and mechanical interconnection~.
5It ls still another ob~ect of the present invention to provide an electric energy meter utlliæing modular construction, the modules of whlch may be manufactured and stocked, and subsequently customized, enabling late polnt feature identlflcation.
It is a further ob~ect of the present inventlon to provlde an 10electronic energy meter which meets industry standards, is versatile in providing increased features and functions, a~d yet wh~ch is interchangeable wlth meters in exl~tl~g installatlons.
It is a still further ob~ect of the present inventlon to provide an electronic energy meter with great versatillty in 15features and functlons, and yet which slmplifles the assembly and accurate testlng of the assembled meterO
In arcordance with one ~mbodiment of the present invention a flexible three module electronlc power meter is provlded including a base module, a voltage module, and a meter-register assembly 20module. Detachable mechanlcal and electrical connectlons are provided. The base module includes terminals adapted to be connected in clrcult with the power source and load to b~ metered and comprises a family of module~ including diff~rent current sensors and ratings,. The voltage module family includes a planar 9~

ll-ME-238 support member parallel to the base Oll which one or more selected transforms are mounted providlng dif.ferent voltage ratlngs and power to the electronics. Siynals provided from the current and voltage modules are nonmalizPd enabling the use of the various s meter-reglster assembly modules with any comblnatlon of current and voltage modules.
The selected current module, the selected voltage module, and the desired meter-register assembly are detachably and readily interconnected by flexible electrical conductors and connectors, and mechanical spacers and support means.
Additional customizing ls posslble late in the manufacturlng cycle or even subsequent thereto by an optlo~al family of output clrcuit boards, to provide slgnal connections between the reglster assembly and the outside of the electronic meter, and further i5 including VARS-Q switching mea~s. In addition, ~umpers are provlded which may be cut to provide thQ deslred nonmalized signals after the current and voltage modules are select~d. Still further fl~xibllity ls provided by s~ltch re~trictors to enable selectlon of those functions accessible to the meter reader from outside the cover.
Bar coding is provlded on various assemblies and other means, lncluding color coding, are provlded to ensure proper assembly and testing of the selec:ted components and modules, providlng a de~lgn which minimizes part:s while ma~imizin~ flexibility and the abllity .

ll-ME-238 to customize electronlc Pnergy meters late in the manufacturing cycle.
DRAWINGS AND BRIEF DESCRIPTION OF INVENTION
FIG, 1 is a front view of ~n electronic energy meter i~corpora$ing tha present invention wlth the shield and cover removed.
F~G. 2 ls a top view of ~IG. 1 with the shield included.
~ IG. 3 ls a side vlew of FIG. 2 with the shield and cover i~cluded.
FIG. 4 ls a rokated slde vlew of a portlon of FIG. 1.
FIG. 5 ls a top view of FIG. ~.
FIG~ 6 iS a cutaway side vie~ o~ a portion of FIG~ 1 showing connectio~s through the base.
FIG. 7 is a top view, i~ reduGed slz~, of the ba~e portlon of FIG. 1.
FIG. 8 is a cross sectlonal side view of the m~ter-register a~sembly portion of FIGo 1~
FIG. 9 is a bottom view of the voltage module of FIG. 1.
FIG. 10 is a side view of the voltage module of FIG. 9.
2Q Referring first to FIG. 1. ~IG~ 1 sho~s an electronic ~nergy meter 10 in~ludiQg a base or current module 12. The base 14 l~cludes 4 positioning tabs molded integral with the base, two of whlch, 16 and 18, are shown. A plurality of terminals such as 22 pass throu~h the base 14 to conQect the meter in clrcuit with a ~ ME-23~

source of power and a load which is to be metered. The base 14 includes a central rim 24 surrounded by the circular step 26 with a narrow "tread" 28~
As best sho~n in FIG. 2, the base 14 also includes three cutouts 32, 34 and 36 e~ually spaced around the perlpheral rlm 40 for inserttng tabs (not shown) in the rim of the cover 156 ~see FIG. 3) to secure the cover to the ba~e. The multiple termlnals such as 22 and base 14 are configured in accordance with the industry standard ANS~ C12.10, 1978 to insure interchangeability and proper fit and orientatlon with ANSI standard meter sockets.
Notwithstanding additional functions and modes of operation provided by the electronic energy metsr 10, it i~ important to be able to directly substitute the electronic energy meter for a less sophisticated electro-mechanlcal en~rgy meter in an exl~tl~g installation.
Two or three current sensors such as ~0, 42 and ~4, are mounted on the terminal extensions above the base 14 as better illustrated and described ln connection with FIG. 4 below. The current se~sors may be of the type described in Unlted States patent application serial number 259,234 filed October 18, 198B by D.F. Bullock, which patent application is assigned to tha same assignee as the present invention, and which is hereby incorporated by reference. The specific current sensors 40, ~2 and ~4 are selected to providE3 the desixed meter ~lass according to ANSI

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ll-ME-238 standards such as class 20 ~20 ampere current flow) and class 200 ~200 ampere current flow). Separate base or curr~nt modules 12 may be manufactured and stucked to meet various meter class requirements and selectively used as building blocks in fabricating customized energy meters as described in more detail below~
As shown in FIG. 1, also molded within the base 14 is a connector cavity 50 including a raisPd pocket 52 above the base 14 and a re-entrant pocket cavity ~4 ~best shown ln FIG. 6) molded within the base. Connector cavity 50 enables the optional connection of a selected output circuit board 58 positioned between the connector caYity and register module 60. The output circutt board 58 provides the flexibility of selecting approprlate slgnal processing and connecting circuitry to enable the interconneGtion of ths electronics associated with re~ister module 60 and cir~uitry outside the meter, through the connector cavity 50, as is described ln more detail below in coDnectlon wlth FIG. 6, and also in unlted States patent applicatlon serial number ~docket ~ E-236) flled by W.R. Germer, J. Stillwagon and P.F. Coryea, a~d assi~ned to the same asslgnee as the present inYention, and whlch is hereby i~corporated by reference.
The base 14 also includes three support receptacles ~4, 66, and 68; two of whlch, 64 and 66, are shown in FI~. 1. The support receptacles each include a bore, such as bore 7~ in support receptacle 64. Three cylindrical aluminum supports 74, 76 and 78 9~

ll-ME-238 are secured within the support receptacles 64, 66 and 68, respectively. As shown in FIG. 1, the. support 74 extends through the bore 72 in support receptacle 64 and includes a central extension 8~ which passes through washer ~6 into a hollow in base 14, and is headed over into header 88 to be secured in place withln the support receptacle 64. The upper end 90 of cylindrical support 74 includes a centrally threaded bore 92.
Posltloned on the supports 74, 76 and 78 ls transverse support member 96. The transverse support member 9~ includes a radlally extsnding tab 100 whlch extends through an aperture in the output clrcuit board 58 to position and support the output circuit board as described in more detail in the aforesaid Unlted States patent applicatlon serial number (docket ll-M~-236). The transverse support member 9~ also supports the transformers such as 100 and 102 within openings and depressions as better shown by, a~d discussed below in connection with, FI~S. 9 and 10. Transformers 100 and 102 are positloned betwee~ the tran~verse support member 96 and the voltage module clr~uit board 110. Depend~ng from the voltaye module circuit board 110 are three electrolytic capacitors 11~, 116 a~d 118. The electronlc clrcuitry and operatlon of the voltage module 112 is described in more deta~l in Unlted States patent application, serial number ~docket ll-ME-249) filed by Warren R. Germer, as~igned to the same assignee as the present invention, and hereby incorporated by reference.

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ll-ME-238 FIG. 2 is a top view sho~ing the layout of the meter register assembly module 60, ancl which includes a readout window 122 in bezel 124. A slot 126 through the nameplate 128 provldes access to an integral test mode actuator and lndicator described in detail ln copending Unlted States patent application, serial number ~docket 11-ME-235), filed by W.R. Germer, E.F. Coryea, A.A.
Keturakis, D~o Masery, a~d T.~. Stevens, and as~igned to the same assignee as the present i~ventions. A plurality of axlally depressible swltches 132, 1~4, and 136 are provided at the top of 10 the meter-register to enable selective actuatlon of a plurality of control functions, such as monthly reset, regis~er display and self chsck. Flexibility as to whtch of these controls can be actu~t d from outside the tran~parent housing by the meter reader through a rotatable and depre~slble switch actuator is described in detall 15 in United States patent application, serial number ~docket ll-ME
237), filed by P.R. Coryea and W.R. G~nmer, assigned to the 5ame assignee as the present invention, a~d hereby i~corporated by r2ferenc~. That patent applicatlon describes swltch restrictors which may be selectlvely applied to one or more of the switches 20 132, 134, and 136 to restrict operation from outside of the transparent housi~g 156 of the energy me~er 10, and thus effectively restrlct what may be actuated by the meter reader who does not remove the meter cover, as contrasted wlth the servlceman or repairman who has the ability to, and may, remove the cover~

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ll-ME-238 The ability of the customer to selectively and readily change which of these switches are to be accessibl.e to the meter reader, and which to the serviceman, furthers the purpose of the present invention to provide maximum flexibillty withln a standardized but modular energy meter configuration.
As shown in FIG. 2, tho nameplate 128 is held in place by plastic nameplate snaps 129, molded as part of the bezel 124, and screws 131 whlch also ground the nameplate. Also, as shown in FIGS. 2 and 3, an electromagnetic ~EMI) and thermal shield 138 extends from the register 60 to the base 14. The sh~eld lncludes a plurality of spring fastener~ 144, 146 and 1~ spaced about the csntral reglon of the EMI and thermal shield which grlp contact portions or extenslons 150 of the transverse support member 96.
The EMI and thermal shleld 138 also includes a ~utout 152 whlch is gPnerally rectangular in shape and whlch provides optlcal visibility through the EMI and thermal shield to tAe bar coded nameplate a~d retainer member 142 positioned on the volta~e module 112. The EMI a~d thermal shleld 138 ls tapered to fit snugly around th~ regist r moduls 60 and extend to the base 14 to flt ~0 sn~gly around the circular step 25 and seat on the narrow tread 28 shown in FIG. 1. The E~I and thenmal shleld 13~ thus mechanlcally interconnects and provides added strength to the modular assembly comprisi~g the base module 12, the voltage module 112, and the regiSter module 60, in addition to providlng th~rmal protectlon, ll-ME-23~

EMI protection and also aesthetically obscuring the electronics within the meter from view from outside the transparent case 156.
In addition, when the case 156 is removed, the shleld which ls grounded through transverse support mlember 96 provides a safety barrier against the serviceman or repalrman accidentally t~uching the voltages within the circuitry positioned wlthln the EMI and thermal shield 138. The details of constructlon of the EMI and thermal shield 138, and lts use within an electronlc energy meter is described in more detall ln United States patent application serial number ~docket ll-ME-253), flled by A. Palmer, M. B~utin, and P.F. Coryea assigned to the same assignee as the present invention, and hereby lncorporated by reference.
A~ b~st shown in FTGS. 1 and 4, the curr~nt senso~s 40, 42 and 44 are connectPd by multi-conductor cables 160, 162, and 164, respectively to connectors 170, 172, and 174 respectlvely, whlch connect the current or ba~e module 12 to the meter-register assembly module 60. The connectors 170, 172 and 174 enable th~
current module 12 to be selectively connected to differen~ meter-register assemblles 60, thus providing still addltional flexibillty in the assembly of an electronic energy meter having all of the required characteristics. It is to be noted that the multiconductor cables 160, 162 and 1~ pass through an openlng in the transverse support member 96 and th~ voltage module 112 behlnd the selectively removable bar coded nameplate and retainer member , ' '' ' . , .

142. The bar coded nameplate and retainer memb~r 14~ lncludes a palr of tabs 176 and 178 at tha top which extend through openings in the voltage module circuit board 110, and are retained at the bottom by the spring fingers 180 and 182 which l~clude a detent whlch reslliently retalns the bar codPd nameplate and retainer member. The bar coded nameplate a~d retainer member 142 is positioned in place after the multi-conductor cables 160, 162 and 164 are placed in posltion extend~ng beyond the circuit board llû.
The function of the multi-conductor cables 160, 162 and 164 can be further understand by reference to FIGS. 1 and 5, and, in particular to FIG. 1 which shows the cables conn cted through connectors 170, 172, and 174, respectively, to the meter-register module 60.
Proper an~ular posltioning of EMI and thermal shlsld 138 is provided to ensure, amon~ other things, that the cutout 152 ls ln alignment with the bar coded nameplate and retainer member 142 to provide optical vislbllity of the bar coded nameplate. Tha angular positlonlng of 2MI and thenmal shleld 138 on the electro~ic meter 2 is facilitated by the gulde 161 (see FIG.2) which extends upward from ~tep 26 (see FIG. 1) a~d which is molded as part of base 14.
A rectangular cutout 163 which is approximately twice the width, and approximately the same height, as ~uide 161 in the bottom edge of the EMI and thermal shleld 138 pa~ses around the guide to provlde the proper angular positioning. The EMI and thermal shleld .~

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ll-ME-238 138 is position~d and rotated about the guide 161 with the assembled posltion of th~ EMI and thermal shleld relative to the guide shown in FIG. 3. FIG. 9, shows the aluminum transverse support member 96. In the assembled position, the teeth of spring 5fasteners 144, 146, and 148 grip the clrcumferential area of the transverse support member 96.
Slnce the width of the cutout 163 is approximately twice that of the guide 161, it provides positive stops for rotation of the EMI and thermal shield 138, first on one side 191 for the assembled 10position shown in FIG. 3, and then on the other side 193 when the side 195 of the cutout 163 of the EMI and thermal shield 138 is rotated i~ the counterclockwis~ direction to disengage the spring fasteners 144, 146 and 148 ln preparatlon for removing the EMI and thermal shield. A~s~mbly of the EMI and the~mal shleld 138 is 15accompllshed by sliding the EMI and th~rmal shield down over the meter-register assembly 60 and volta~e module 112 to base 14 with the side 195 of cutout 1~3 ad~acent the slde 1~3 of gulde 161.
After the EMI and thermal shield 138 is seated i~ th~ c~rcu~ar step 26, it ls rotated clockwise so that the fasteners 144, 146 and 148 20are slid into frlctional grlpplng engagement wlth the bottom and top of the transverse support member as described in detail in the aforesaid United Sta~es Patent application, serlal number ~ ME-253). At the s~me tlme, the cutout 152 is rotated int~ alignment with the bar coded nameplate and retainer members 142 to provide 9 ~l r ~

ll-ME-238 optical visibllity of the bar coded nameplate.
The close fit between the EMI and thermal shield 138 and the planer transverse support member 96 provides strength and rigidity to the EMI and thermal shield and helps prevent denting of the relatively thin EMI and thermal shield when the energy meter 10 i5 handled or serviced with the cover 156 removed. The steel EMI and thermal shield 138 thus provides electromagnetlc shieldiny by grounding through transverse support member 96, provides support and strength to the electronic energy meter 10~ is thermally reflective, aesthetlcally covers and obscures the i~terior of the energy meter even with a transparent cover 156, and in additlon provldes a grounded safety shield when the cover ls removed by a servlceman, preventing ths flngers of the serviceman from contacting the voltages present at many places within the electronic energy meter 10.
The meter-register assembly mndule 60 1s spaced from, and support~d on, a transverse support member 96 through resilient upper support posts 184, 186, and 188, respectlvely. The upper support post 184, 186 and 1~8, as shown in FI~. 4 includ~s at the lower end a shoulder 190 which fits withln a matching opening in the transverse support member 96 and a smaller diameter threaded rod 192 which is threaded into the centrally threaded bore g2 withln the cylindrical support 74. Thus, the support post 184 i~
inserted through the transverse support member 96 and threaded into .

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ll-ME 238 the support 74 to secure the voltage module 112 in place, whlle at the same timP providing detachable support for the meter-r2glst~r 50 as described below. Thb upper support posts lR4, 186 and 188 lnclude a resllient U-shaped upper end (be~t shown in FIG. 4~
lncluding lnwardly tapering edges 196 and 198 and annular groov0 200, whlch provides a resillent, selectlvely detachable, support for mating sockets ln the bottom of the bezel 124 of the register module 60 as described below in connection with FIG. 8. The support posts 184, 186 and 188 may be fabricated of aluminum, or a molded plastlc. If plastlc support posts are used, the ground connectlon from th~ voltage module to the register module 62 may be made through ribbon cable 324.
FIG. 4 also illustrates the interconnection of the current sensors 40, 42 and 4~ to the tenminals ln th~ mater base.
Referring to FIG. 4, lt ls to be noted that current sensor 42 is directly supported o~ and connected to tenmlnal 206 and is connected to tenmlnal 208 by the a~gularly extendlng bar 210 such that current flow in a power lin~ under measurement passes through the current sensor ~2 by ~ay of terminals 206 and 208. The base module 12 may be either self-co~tained, or transformer rated, to match the particular basic fonm of the energy meter a~cordi~g to the application description of ANSI standard C12.10 and establish the desired clas5 or current ratlng. A ce~tral row of term1nals such as 214 are auxillary terminals, and in transformer rated 3~i meters provide auxiliary access to the energy meter 10 such as for the potential connections. In some transformer rated versions of the ANSI standard S-based meter, the pulse initiator KYZ
connections may be made through spare ones of these auxiliary terminals, such as 21~ shown ln FIG. ~. There may be a many as seven auxiliary terminals in a row through the central re~lon of the meter base, and three of these auxiliary termlnals may be used to provide the KYZ connections. In order to be able to selectively couple the K~Z tenminals to the electronic energy me,ter 10, they are wired via conductors 220, 222, and 224 which detachably mate with pins 230, 232 and 234 of the edye con~ector 236 lncluded on the output circuit board 58 ~see FI~. 6).
FIG. 6 also shows the connection of one of a family of output circuit boards 58 which provlde selectively attachable (and detachable3 signal intercon~ectlon and conditionlng bet~ean a connector 59 on the register module 60 and the outside of th~
electronic energy meter 10 (see FIG~ 1) as d~srrlbed in detall t~
copending United States patent applicatlon, serial number (ll-ME-236) filed by W.R. Germer, J. Stillwagon a~d P.F. Coryea, a~d assigned to the same asslgn~e a~ the present invention, and which is hereby incorporated by reference. The output clrcuit board includes a plurality of connector pins 238 ~hlch extend through the base 14 of electron:ic energy meter 10 to a re-entrant pocket 243 in the base. Connections may be made to the conneotor pins through .

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' 9~'.a ll-ME~~38 a plug connector 240 which is inserted into the re-entrant pocket 243 and which then connects the register module 60 with the outside of the energy meter throu~h cable 244. A pivoted resilient latch 216 on the plug connector includes a proje~tion 245 whlch extends into an aperture in the wall of th~s cavity 54 when tha plug connector is pos~tioned in the re-entrant pocket 243. The plug connector 240 may be disconnected by pressing against the bottom of latch 216 to move the pro~ection 245 out of the aperture, and pulling the plug connector downward out of contact with connector plns 238.
The specific electroni~s included on the output printed board 50 will depend on the speciflc funrtlons and modes of operation desired, or required, by the customer, and by the spe~ific lnstallation. There are many potential options such as the provision of a sig~al to indlcate the end of the demand interval, a demand threshold alert, pulse inltiatlon, a~d varlous lndlcating and built-in test ~unctions. However, wlth only 6 or 8 output clrcuit boards wlde flexibility and versatility may be reallzed in meeting substantially all of the common slgnal requirements.
Thus, the ba~ic energy meter may be built and stocked wlth late polnt identification of speclfic features for a specific meter, including later selecting or changing the output eircuit board to meet new or different customer requirements and features~ Removal, and insertion of the same, or a different, output circuit board ls ll-ME-238 slmple and qulckly accomplished. Thls also slmpllfies repalr a~d maintenance of the boards, a~d of the energy meter.
The output circuit board 58 may also include a vAR-Q switch, shown as a slidlng swltch 246 i~ FIG, 6. Alternatively, a ~umper arrangement could be provlded to hard wire in the VAR or Q hour operation. That is J the family of output clr~uit boards 58 whlch may ~e selectively connected to provide signal connection and conditioning between the meter-reglster module 60 and the outslde of the electronic energy meter 10 may be provided with even increased flexlbility through switch ~46 to enable selective operation to provide VARS or Q hour output. ~ descrlption of the circuitry for use in VAR-Q switchlng is described i~ copendl~g United States Patent Application serial Qumber (ll-ME-~52) filed by B. whlte, M. Negabah~, M.J. Ouellette, and W.R. Germer, and ~ssigned to the same assigne~ as the pre~ent l~ventio~.
FIG. 7 is a top view of one base 14 used in a transformer rated meter and showing the conn~ctlon of the KYZ connector 226 through leads 220, 222 and 224 to the i~ er~al portions of the auxiliary t~rminals 250, 252, 254, respectlvely. In additlo~, a plurality of indlvidual connectlons ar~ made to the varlous other auxiliary terminals, with each of the individual connections including a lead terminating ln a re~ilient socket connector. I~
the particular arrangement shown ln FIG. 7, which is an ~N~I
standard form 9S meter, lead 260 is connected betwe~n the female 1~

ll-ME-238 socket connector 270 and the auxiliary terminal 261, lead 262 is connected between the socket conne~tor 272 and auxiliary terminal 267, lead 264 is connected be ween socket termlnal 274 and auxiliary terminal 267, lead 266 is connected betw~en sockst 5terminal 276 and auxiliary tenminal ~7, lead 2~8 is connected between socket terminal 27~ and auxiliary terminal 2fi5, and lead 269 is connected between soc~et termlnal 279 and auxillary terminal 263. That is, there is a lead and connector to each of the four auxiliary terminals whlch do not include the KYZ connector, and 10tenminal 267 includes two additional leads and connectors.
The v~rious base or current modules 12 provide the energy moter 10 with the capabillty to be completely intercha~geable w~th, and th~s replace, existing and installed ener~y meters, and which may, for example, uttlize the KYZ tenmlnals ln the meter base.
15That is, form, fit, and function of the meters are made interchangeable, even though the electronic energy meter 10 ha~
greatly expanded capabllitle~ and functlons such as built-in test and other functions described above~
Leads 260, 262, 264, 266, 268, and 26g provide voltages to th~
20voltage module 112 to po~er the voltaye module and clr~uitry in energy meter 10, and ~or the measurement of those voltages, and are connected to their respective male connectors through socket tenminals 270, 272, 274, 276, 278, and 279 which pass through openings or slots in the transverse support member g6. As shown ll-ME-238 in FIG. S,. opening 284 is provided in support member 96 below terminals 286 and 28~ which extend downward or depend from the voltage module circuit board 110. Terminals 292 and 296 extend downward from the voltage module circuit board 110 through openln~
292 in the transverse support member 96, terminal 302 extends downward from voltage module circult board 110 through the slot 300 in the support member, and terminal 306 similarly extends downward from the voltage module circuit board through th~ slot 304 in the transverse support member.
As shown i~ FIG 5, the upper surface of the voltage module circuit board 110 includes indicia of the color nf the lead to be connected to the termlnal which extends below the indicla.
Ad~acent terminal 286 is the indicia 287 ~GRN~" ad~acent terminal 288 is the lndicla 289 "BLU," ad~acent termlnal 29~ ls the lndicla 295 "WHT," ad~acent tenminal 296 is the indlcla 2g7 ~YEL,~ ad~acent tenminal 302 is the indicla 303 ~ORG, n and ad~acent tarmlnal 306 is the indicia 307 "RED." These indicla indic~te the color of the lead to be connected to the connector u~der the circult board 110 at that point, which colors are respectively, green, blue, white, yellow, orange, and red. The indicia 287, 2~9, 2~5, 29~, 303 and 307 are formed by deposltion on the surface on the voltage module clrcuit board 110 at the same time that the conductors or runs are deposited on the circuit board. Leads 260, 262, 26~, 266, 268 and 269 are similarly color coded to mi~lmize the possibillty of .
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ll-ME-238 incorrect connections between the base module 12 from th~ auxiliary terminals 261, 263, 265, and 267 to t.he voltage module 112. The same color codln~ is used for the fami.ly of base modules 12 whlch conform to the ANSI standard such that the same color coded voltage module 112 may be used with the various base modules even though particular base modules may have fewer leads than 260, 262, 264, 266, 268 and 269.
It is to be noted that the top surface of the voltage module circuit board 110 includes bar code indlcla 308 and as shown in FIG. 4 the voltage module 112 also includes a bar code 310 on the bar coded nameplate and retainer memb~r 142. These bar codes are readable by an optical scanner during the manufacture or repair of the meter to accurately identify the particular configuration of module compo~en~s whlch have been conn~ctsd in order that the automatlc test equipment will perform the proper test for that particular configuration~ Th~ ~utout 15~ in the EUI and thermal shleld 138 (see FIG. 3) is positioned ad~acent the bar code 310 on the member 142 when the meter ls assembled such that the proper test procedures can be applied to the partlcular meter by opt~cally scannlng the bar codç through the EMI ~nd thermal shleld through the transparent cover 138, without removing the cover at the tlme of test. Thls bar coding identifies the basic meter lOl, that ls the meter lO less the register module 60, as shown in ~IG. 4, and identifies and enab.les proper testing of various connections a~d 3~L~

~ ME-238 voltage ratings. The various other modules of electronic energy meter 10 also include bar coding which is positioned to be visible to be both machine readable and human readable. The bar coding 308 for the voltage module 112 which is provided on the top of voltage module circuit board 110 (see FIG. 5) identifies the voltage rating and number of transformers included in the particular voltage module. The plastic shield 103 over output circuit board ~8 (see FIG. 1) includes other bar coding which identifles various functions resident on the particular output clr~uit board.
Sim~larly the register module 60 includes bar coding on the top of bezel 124 (see FIG. 8~ to identify the register and its fu~ctions. Bar coding may also be placed on the n~meplate 128 (see FIG. 8) to identify the completed electronlc energy meter 10 and its functlons resulting from the flexlbla selectio~ of the various modules. Thus, it is to appreciated that conslderable attention has been provided in the de~ign of the electronic e~ergy meter 10 to prevent errors in the i~terronnectlon of the various modular and versatlle assem~lies whlch flexlbly provide the various functions and modes of operatlon re~uIred by the custom~r.
Still further versatillty is provided by the ~umpers 314, 316, 318, and 320, (best sho~n i~ F~. 5~ which are connected in the circuitry of the voltage module clrcuit board 110 across notches 315, 3~7, 319, and 321, respectively. The de~ired comblnation of ~umpers are cut duri~g assembly to form a digital word descrlbing ~v~

~ ME-238 the required multlpllcation for the particular meter to meet the required form. A form of a meter is an applicatlon description according to ANSI standard C12.10 whlch lncludes the definition for each clr~uit application, that is how the voltages and currents axe to be multiplied together to pro~ucl~ the requir~d watts output.
In an analog electro-mechanical eneryy meter, thi function is hard wired lnto the energy meter, requiri~g the provislon of dlfferent models for dlfferent circult applications. In the digital electronic meter 10 of the present inventlon, the multiplication of the digital representatlon of the input slgnals can b~
controlled to conform to the application as required through the ~oftware involvedO The plac~ment of the ~umpers 314, 316, 31a and 320 on the voltage module 112 e~ables the ~umpers to be cut to ta~lor the basic meter (that shown ln FI~, 4~ in light of a specific configuration of current sensors prese~t in the selected current module 12 and voltage module 112 to normalize and provlde standard slgnals from the basic meter. One ~ump r dascribes and~or selects the prop~r slgnal pxocessing dependlng on whether the basic meter is self co~tained or transformer rated whlle the remainlng ~umpers deflne th~ partlcular meter type. Accordingly, the ~umpers 314, 316, 318 and 320 are provided i~ the cir~uit board 110 in order to provide increased flexibility by enabling selectlve cutting of the approprlate wire ~umpers durlng a~semb~y to form the appropriate digital word to describe the required multipllcations ~49~

~ MB-238 which will match the required ~orm. That digital word becomes an additional input supplied by the voltage module 112 to the re~ister module 60. Providing normallzed standard signals from the basic meter, which is customized from the point of view of current and voltage ratings and configurations, and which describes a particular ANSI meter form, enables the selective use of unlversal meter-registers which are suitable for use with the various customized basic meters 101. Rsglsters suitable for use with any of the customized basic meters may include demand registers, various time of use registers, KVA registers, a~d recording demand registers. These various types of registers with various ra~ges may be manufactured and stocked as modules. The select2d meter-register module may then be readlly attached to the customized basic meter to further customlze the completed eneryy meter, addl~g a further element of flexibility in accordance with the prsse~t invention.
In addition, the reglster and meter fu~ctions are t~u~
combined in the meter-reglster a~sembly module 60 so that the ba~lc modules are reduced to only 3, the base or current module 12, the voltage module 112, and the register assembly or module ~0. The-~e are readily and selectively interconnected mechanlcally and electrically/electronically as described in connection with the present invention.
Connections from the voltage module 112 to the register module .

~ .
.

3~

~ ME-238 60 is provided by the multi-connector ribbon cable 324 shown in FIGS 1 and 5. Referring to FIGS 1 and 5, the conductors such as 326 extend through thP voltage module circuit board 110 and are connected in cir~uit with leads ~nd/or components on both sldes of the circuit board, which are connecte.d through the ribbon cable 324 to connector 328 wh1ch is used to connect a basic meter 101 comprising the base module 12 and the voltage module 112 to the selected register assembly module 60. ~s a result, the modular construction of the present invention enables and facilitates the interchangeability of the three layers or modules of ~h~ el~ctronic energy meter 10 thrnugh the use of detachable connectors a~d supports between the current module and voltage module, between the voltage module and the register module, and between the base module and the register module. This provides greatly expanded capabilities to select, interconnect, assemble, customize and test ths electronic energy meter with a minimum effort and chance of error, even wlth the large number of combinations and features and modes of operation provided. The i~terchangeable electrical and mechanical interconnectlon arrangement of the present invention ~0 minimizes the tlme and expensa of assembly, and also minimlzes the potential of interconnection error.
Base module 12 also includes a ground connection to the electronic circuitry of the energy meter. Referrlng to FIG 7, a ground lead 330 is provided with a spade lug 332 at its free end, 9~

~ ME-233 and a spade lug 334 at its inner end. The spade lug 334 is riveted through the base 14 to a spring clip (not show~) underneath the meter and grounds to the base of the meter socket (not sho~n) when the meter is inserted in its socket. The free end of the ground lead 330 is connected through spade lug 332 to ground the tr~lsverse support member 96 of the voltage module 112 by positioning the spade lug between the alumlnum support 74 and the resilient support post 184, thus providing a detachable ground connection between the outside of the energy meter 10 and the 10 el~ctronics of the energy meter.
The details of construction of the voltage module 10 are best shown in FI~S. 9 and 10. R~erring to FIGS. 9 and 10, lt is to be noted that th~ transformers 101, 102, 104, a~d 106 are positioned ~ithin openings such as 338 and 340 within the transverse support 15 member 96 with thelr cores 342 and 344, respectively, abutting the transverse support member 96 as best shown in FIG 9, and thelr coils 346 and 348, respectively~ extending both above and below the transverse support member. The transfonmers are held in place, with bifurcated clamps 352 and 35~ posltioned to overlap the cores 20 of transfonmers 104, 106 and 101, 102, respectlvely. The opposlt@
corner of transformer 104 is secur~d by clamp segment 356, the opposite corner of transformer 102 is secured by clamp segment 35~, the opposite corner of transformer 101 is secur2d by cl~mp segment 362, and the opposite corner of transformer 106 is secured by clamp ;

~q3~

ll-ME-238 segment 360. Clamp segments 356, 358,,and 360, 362 are also formed as a pair o~ bifurcated clamps. Thus, diagonally opposite corners of each transformer are secured in place by clamps which extend from the transverse support member 96 to the bottom of each transformer, securing the transfonmer between the tra~sYerse member and the d amp. Coils 346 and 348 of transformers 102 and 104, respectively, are positioned on elther side of the cores 342 and 344, respectively, wlth a portion of each coil posltloned between the transverse support member ~6 and the voltage module clrcuit board ~110. Each of th~ four ~lamps namely bifurcated clamp 352;
blfurcated clamp 35~; clamps 356, 3~8; and clamps 360, 3~2 ar~
s~cured to a spacer post such as 366, 368, and 370 (shown ln FIG
10) whlch are positioned between, and se~ure, the transverse support member 96 and the voltage module printed ~lrcuit board 110.
The spacer posts, such as 366, include a ~hreaded base to receiv~
screw 378 and a threaded central extenslon 3~6 havlng a smaller dlameter than th~ post extends through the voltage module circuit board 110, and is secured by nut 380. ~n annular rim 382 on the spacer 366 ad~acen the transverse support member 96, and the 20 shoulder 384 formed by the reduced dlameter step of the threaded extenslon 376 maln1:ains the spaclng and dlstance between the transverse support memb~r and the circuit board 110. As a result~
the transfonmers 100, 102, 10~, and 106 may be selectively positioned and retained within the voltage module 112, and their ll-ME-238 voltage characteristlcs and ratings are selected to meet the particular customer requirements. ~lhere may be two or three voltage sensing transfonmers as required by the ANSI standard C12.10 form description. The fourth transformer such as that shown in FIGS 8 and 9 comprises the power transformer of a built-in power supply circuit, the electronlc components of whlch are attached to the voltage module circuit board 110. The voltage ratings of the transformer primary windings establish the voltage of the module, and also that of the electronic energy meter 10. The selected voltage module 112 and current sensors 40, 42 and 44 reduce and normalize the voltage and current inputs to the energy meter 10 to a lsvel sultable for direct applicatlon of the electronic circuits to the energy meter. As pointed out above, an objectlve of the electronic energy meter 10 ls to provide a standard modular ener~y meter configuratlon with maximum bullt in fle~ibillty to meet customer requirements and speclfications.
A meter-register module 60 suttable for use with the flexible basic meter assembly 101 shown in FIG. 4 having d~lned functlons such as Maximum D~mand, Tim~ of Use and other functions is selectively connected to the basic meter. The electrical co~nsctions to the meter-register module 60 have been described above, and are provided through attachable (and detachabls) connectors which connect the register module to the voltage module 112, and also to the base or current modul~ 12. Mecha~ical support ~'~D~

~ ME-238 upon, and spacing from, th~ voltage module 112 ls provided by the support posts 184, 186, and 188. The inwardly tapering edges 196 and 198 at the ends of the support posts, and annual grove 200 (best show~ in FIG. 4) mate with apert:ures in the register module 60.
Referring next to FIG. 8, the bezel 124 of the rPgister module 60 is spaced from the meter-register circuit board 386 by the rim 388 of the bezel 124, and secured in place by a plurality of resilient fasteners such as 392 and 394. Fasteners 392 and 394 are molded integral with the bezel 124 and include Pxtensions ~uch as 39~ and 400 with tapered and rounded end ~aws 402 and 404 connected to the extenslons by a step or ridge 406~ When the register clrcuit board 386 is pressed down around the resilient faste~ers, such as 392 and 394, the tapered ~aws ~02 and 40~ are forced toward one another until they pass through the apertures in the register circuit board, after whlch they-sprlng outwardly with the ridge 40~
positloned securely about the ap~rture, and agal~st the bottom of the register circult board.
Three apertures, such as 410 shown in FI~. 8, are provided in appropriate posit~ons to cooperate with the upper support posts 184, 186, and 188 ~see FIG 4), and are dimen~ioned to securely fit around the annular grove 200 in the resilient support post. I~
securing the appropriate meter-register moduls 60 to the basic meter 101, that is; the register appropriate for the meter as ~3~3.17 ~:~

ll-ME-238 configured to meet the customer re~irements and late feature identification described above, the register module is positioned ovar the upper support post 184, 186, and 18~ as shown in FIG 4 such that the apertures 410 conkact the inwardly tapering edges such as 196 and 198. Downward pressure on the register module 60 forces the open jaws formed by the tapering edges toward one another until the aperture 410 is pressed into the region of the annular grove 200, at which point the resillency of the compressed tapered ~aws causes the jaws to spring outward, flrmly seating the annular grove 200 around the rim of the aperture ~10 on either slde of the register circuit board 386. The connector~ 170, 172, 17~, and 324 are then attached to connect the register module 60 in circuit w~th the basic meter assembly.
Thus, the present lnvention i~corporates ~ flexible modular constructlon ln which each of the modules are provided wlth a baslc vsrsatile structure which ls readily ~ustomized in those areas where variable fu~ctlons and modes of operation requir~
customization. Detachable compo~ents and coDnector~ shorten the t~me and effort required to cu~tomlze the meter, while at the same time minimlzi~g chances of error. Th electronic energy meter 10 ls readily adaptable to mass productlon of basic components whlch are then selectively combined to meet sub~tantially all foreseeable customer requirements wlth a mln~mum of parts and maximum flexibility. This allows the manufacture and stocking of basic ' ~ ME-238 modules and components, with late pc~int feature identification whlch can be readily incorporated to c:ustomtze the basic meter to meet the differing customer speclfications and requirements. Thls simplified and less costly electronlc energy meter is efficient not only in man~facture, but also in the stocking of spare parts and ~n the repair and maintenance of the meter.
Thus, whlle the present invent~on has been described through preferred embodiments, such embodiments are provided by way of axample only. ~umerous variatlons, changes and substltutions, including those discussed abova will occur to those skilled in the art-without departing from the scope of the present invention and the following clalms.

-,,- ,, , . ~

~ . . . . .. . . .

Claims (67)

1. A modular flexible electronic energy meter adapted to enable manufacture of basic components with the late point identification of features and functions, and with built in provisions to later customize the power meter to incorporate such features and functions comprising:

a current module selected from a plurality of current modules of various ratings including a base with terminals extending through said base from outside said power meter and adapted to connect said electronic power meter in circuit with a source of power and a load to be metered;

said current module including means to secure and connect one or more current sensors to the interior of said current module to provide the desired current capability class;

a voltage module selected from a plurality of voltage modules of various ratings and including a substantially planar support member substantially parallel to said base and a means to secure and connect one or more selected transformers;
said voltage module being detachably supported on said current module; and a meter-register assembly selected from a family of meter and meter-register assemblies of various functions being detachably supported on said voltage module;
said meter-register assembly being provided with normalized standard signals from said current and voltage modules and being compatible with the various combinations of current and voltage modules.

2. A modular flexible electronic energy meter of claim 1 wherein flexible conductors with connectors adjacent said register assembly are provided to interconnect the circuitry of said register assembly and said voltage and current modules.

3. A modular flexible electronic energy meter of claim 2 wherein said voltage module includes a voltage circuit board with connectors to enable selectively detachable connections to the circuitry of said voltage circuit board from said current module.

4. A modular flexible electronic energy meter of claim 3 wherein at least some of the selectively detachable connectors pass through said planar support member.

5. A modular flexible electronic energy meter of claim 4 wherein at least some of said selectively detachable connections pass through openings in said support member to connect to connectors positioned on said voltage circuit board.

6. A modular flexible electronic energy meter of claim 5 wherein said voltage circuit board includes a power supply for providing power to at least some of the electronic circuitry within said power meter.

7. A modular flexible electronic energy meter of claim 6 wherein said planar support member includes openings configured to receive one ox more transformers.

8. A modular flexible electronic energy meter of claim 7 wherein a transformer for said power supply is positioned within one of said openings of said planar support member.

9. A modular flexible electronic energy meter of d aim 8 wherein detachable securing members are provided to secure said one or more transformers to said planar support member.

10. A modular flexible electronic energy meter of claim 9 wherein there are openings in said planar support member to receive up to four transformers.

11. A modular flexible electronic energy meter of claim 10 wherein said one or more transformers each include a core and said detachable securing members are clamps provided at the intersections of two adjacent transformers.

12. A modular flexible electronic energy meter of claim 11 wherein a plurality of spacers are provided between said planar support member and said voltage circuit board, and each of said clamps are secured to said planar support member by fasteners which pass through said planar support member into a threaded bore in one of said spacers.

13. A modular flexible electronic energy meter of claim 12 wherein said spacers include a threaded central extension which extends through said voltage circuit board and is secured thereto by an internally threaded member on the opposite side of said voltage circuit board.

14. A modular flexible electronic energy meter of claim 13 wherein said voltage circuit board is secured between shoulders formed on said spacers around the threaded central extension and said internally threaded nut.

15. A modular flexible electronic energy meter of claim 14 wherein said transformers include coils extending substantially perpendicular to said cores, with a portion of said coil positioned between said planar support member and said voltage circuit board, and said core and the opposite portion of said coil being positioned beneath said planar support member.

16. A modular flexible electronic energy meter of claim 7 wherein said planar support member includes a dished rim around at least a substantial portion of each of said openings to receive and position a transformer.

17. A modular flexible electronic energy meter of claim 16 wherein the top of said voltage circuit board includes a bar code identifying the nature of said voltage circuit board to facilitate the identification thereof.

18. A modular flexible electronic energy meter of claim 17 wherein said voltage circuit board is connected to said register assembly through a ribbon cable, the conductors at one end of which are wired in circuit with said voltage circuit board, and the other end of which is wired to a connector positioned adjacent said register assembly.

19. A modular flexible electronic energy meter of claim 4 wherein the detachable connectors which connect said current module to said register assembly pass through openings in the periphery said planar member and the periphery of said voltage circuit board and are retained in position by a planar retainer detachably positioned between said planar support member and said voltage circuit board.

20. A modular flexible electronic energy meter of claim 19 wherein said openings in the periphery of said planar support and voltage circuit board are edge slots.

21. A modular flexible electronic energy meter of claim 20 wherein said retainer includes one or more extensions from one edge which pass through openings through said voltage circuit board, and said planar support includes one or more resilient fingers which support and position the edge opposite said one edge of said retainer member.

22. A modular flexible electronic energy meter of claim 21 wherein said retainer member has a retainer bar code identification identifying the nature of said electronic energy meter to facilitate the identification and proper testing procedure thereof.

23. A modular flexible electronic energy meter of claim 22 wherein said printed circuit board includes one or more capacitors which extend downward through openings in said voltage circuit board.

24. A modular flexible electronic energy meter of claim 23 wherein said electronic energy meter includes an electromagnetic interference and thermal shield surrounding said voltage module and extending from said register assembly to said base, and said electromagnetic interference and thermal shield includes an aperture to enable said retainer bar code to be visible from outside said electromagnetic interference and thermal shield.

25. A modular flexible electronic energy meter of claim 24 wherein said electronic energy meter includes a transparent housing extending from said base and surrounding said voltage module and said register assembly with said retainer bar code being visible from outside said meter.

26. A modular flexible electronic energy meter of claim 3 wherein said base includes a plurality of hollow supports extending upward and integral therewith.

27. A modular flexible electronic energy meter of claim 26 wherein a second support is positioned in each of said hollow supports and secured to said base, said second supports extending to said planar support member to detachably support said voltage module above said current module.

28. A modular flexible electronic energy meter of claim 27 wherein each of said second supports includes a threaded bore at the end adjacent said planar support member, and said planar support member includes holes over each said threaded bore through which a fastener, having a threaded central portion, passes to secure said planar support member to said second supports.

29. A modular flexible electronic energy meter of claim 28 wherein said fastener is at the first end of third supports which extend between said voltage module and said meter-register assembly.

30. A modular flexible electronic energy meter of claim 29 wherein said third supports are detachable, and include resilient fingers having tapered edges at their other end, and an annular groove around the periphery of said third supports below said tapered edges, said taper extending inwardly toward the other end of said third supports remote from said voltage module.

31. A modular flexible electronic energy meter of claim 30 wherein said register includes a plurality of apertures in the bottom thereof positioned to mate with said resilient fingers of said third supports when said register is pressed over said third supports such that said tapered edges press said fingers toward one another until the apertures pass said fingers to be retained in said annular groove with the tapered edges overlying the top of said groove.

32. A modular flexible electronic energy meter of claim 31 wherein said register assembly includes a register circuit board at the bottom thereof, and said apertures are in said register circuit board.

33. A modular flexible electronic energy meter of claim 32 wherein said register circuit board includes the electronic circuitry for both the meter and register functions.

34. A modular flexible electronic energy meter of claim 33 wherein said register assembly includes a bezel having a plurality of resilient fasteners extending downward to support and position said register circuit board below said bezel.

35. A modular flexible electronic energy meter of claim 34 wherein said resilient fasteners have tapered segments at the ends adjacent said register circuit board, and an annular groove around the periphery of said resilient fasteners above said tapered segments, said taper extending inwardly toward the bottom of said resilient fasteners remote from said bezel.

36. A modular flexible electronic energy meter of claim 35 wherein said register circuit board includes a plurality of apertures positioned to mate with said resilient fasteners of said bezel when said register circuit board is pressed over said tapered segments which presses the tapered segments toward one another until the apertures pass over said tapered segments to surround and be retained by said annular groove with the tapered segments overlying the bottom of said groove.

37. A modular flexible electronic energy meter of claim 4 wherein said base includes a circular step, and a removable electromagnetic and thermal heat shield surrounds said voltage module and extends from said circular step to the circumference of said register assembly, said electromagnetic and thermal shield including fasteners to secure the shield to said substantially planar support member and provide rigidity and strength to said electronic energy meter.

38. A modular flexible electronic energy meter of claim 37 wherein said electronic energy meter includes a selectively detachable output circuit board to provide desired signal connection and conditioning between the outside of said electronic energy meter and said register assembly, said output circuit board

39 including a connector at the top and bottom thereof, the bottom, connector of which passes through said base and the top connector of which mates with a connector in said register assembly, such that said output circuit board may be selectively connected in circuit with said register assembly.
39. A modular flexible electronic energy meter of claim 38 wherein said output circuit board is surrounded closely by an electromagnetic and thermal shield which retains said output circuit board in position with said top connector in contact with the connector in said register assembly.

40. A modular flexible electronic energy meter of claim 3 wherein said voltage circuit board includes four notches at the periphery thereof across each of which a jumper is positioned and connected in circuit with conductors on either side of said jumper, such that one or more of said four jumpers may be cut to flexibly convert said electronic energy meter to a different form for the multiplication of currents sensed by said current module and voltages sensed by said voltage module.

41. A modular flexible electronic energy meter of claim 34 wherein said register circuit board includes a plurality of edge connectors, the pins of which extend substantially parallel to said register circuit board.

42. A modular flexible electronic energy meter of claim 41 wherein said edge connectors on said register circuit board are positioned within apertures in the bezel of said register assembly.

43. A modular flexible electronic energy meter of claim 42 wherein said electronic energy meter includes a transparent housing, said meter-register assembly includes a plurality of axially depressible shafts for push button switches positioned on the top thereof below said transparent housing, an actuator extends through said transparent housing and is positionable to depress a selected one of said switches, and one or more switch restrictors selectively and detachably positioned about one or more of said switches to preclude actuation by said actuator enabling selection of which switches can be actuated from outside said housing.

44. A modular flexible electronic energy meter of claim 43 wherein said one or more switches having their actuation from outside said housing restricted by said one or more switch restrictors may be actuated by manually depressing said one or more switches when said housing is removed, whereby said restrictors selectively enable a separation of those meter functions which may be actuated by a person having access to said actuator from outside said electronic energy meter, and those meter functions which may be actuated by a person having access to the inside of said electronic energy meter.

45. A modular flexible electronic energy meter of claim 44 wherein said actuator includes a locking arrangement to control and limit the access to the operation of said actuator.

46. A modular flexible electronic energy meter of claim 45 wherein each of said switch restrictors comprise a removable sleeve having an interference fit in a groove around a shaft in said bezel of said register assembly and which surround only an arcuate portion of the circumference of said shaft enabling the depressing of such shafts in the arcuate portion which is not surrounded by said switch restrictor.

47. A method of assembling a modular and flexible electronic energy meter compatible with late point identification of features to enable customizing of the power meter to later incorporate a variety of features and functions comprising the steps of:
fabricating a family of current modules by molding a base including a plurality of terminals attached to and passing through said base for connecting said electronic energy meter in circuit with a source of power and a load to be metered in accordance with industry standards, and including a plurality of vertical support members;
providing means to fasten selected current sensors to said terminals;
fabricating a family of voltage modules including a planar support member and further including means for receiving one or more selected transformers by said support member, and providing connecting means on said planar support member which substantially correspond in position to said vertical support members;
fabricating a family of meter and meter-register assembly modules including a register face on the top surface thereof and providing spaced connecting means thereon;
stocking said modules;
subsequently customizing one or more of said modules by selectively performing the following steps on the selected one or more of said modules;
connecting one or more selected current sensors of the desired ratings to said current module to selected one or more of said terminals, and connecting electrical leads from said current sensors to one or more current module connectors spaced from said current sensors an adequate distance to reach said meter-register module when said modules are assembled;
providing a voltage circuit board for said voltage module and positioning one or more selected transformers of desired ratings on said planar support member and connecting said transformers in circuit with said voltage circuit board; and connecting multiple electrical leads from said voltage circuit board to one or more voltage module connectors spaced from said voltage circuit board an adequate distance to reach said register module when said modules are assembled;
spacing a meter-register assembly circuit board from the face of said register assembly module and fabricating electronic circuitry thereon which in combination with said register assembly circuit board provides selected meter functions; and connecting a plurality of connectors to said meter-register assembly circuit board configured to mate with said one or more current module connectors and with said one or more voltage module connectors; and subsequently assembly said voltage module to said current module through said vertical support members to secure said voltage module in spaced relation substantially parallel to said current module; and securing said meter-register assembly module to said voltage module through detachable spacers between said planar support member and said register assembly module; and connecting said current module connectors and said voltage module connectors to said plurality of connectors in said register assembly module.

48. The method of fabricating and subsequently customizing an electronic energy meter of claim 47 with the additional step of connecting detachable leads from said current module to said voltage module through connectors at the end of said detachable leads and connectors provided on said voltage circuit board.

49. The method of fabricating and subsequently customizing an electronic energy meter of claim 48 including the additional step of aligning the connecting means of said register module to substantially correspond in position to said vertical support members of said current module.

50. The method of fabricating and subsequently customizing an electronic energy meter of claim 49 wherein said register assembly module is assembled to said voltage module by aligning said spaced connecting means on said register module with said vertical support members of said current module, providing apertures in said planar support member of said voltage module aligned with said vertical support members, and detachably attaching said current module by passing threaded ends of said detachable spacers through said apertures in said planar support member to connect to said vertical support members and secure said planar support member between said vertical support members and said detachable spacers.

51. The method of fabricating and subsequently customizing an electronic energy meter of claim 50 wherein a voltage circuit board is provided for said voltage module, and a power supply circuit for electronic circuitry for said electronic energy meter is carried by said voltage circuit board, and energization for said power supply is provided through one or more of said detachable leads from said current module to said voltage module.

52. The method of fabricating and subsequently customizing an electronic energy meter of claim 51 wherein capacitors are connected to said voltage circuit board and extended through apertures in said planar support member.

53. The method of fabricating and subsequently customizing an electronic energy meter of claim 52 wherein said power supply is configured to provide the power ratings required by the selected register assembly module.

54. The method of fabricating and subsequently customizing an electronic energy meter of claim 50 wherein a connector receptacle including a plurality of spaced holes is molded in said base, an edge connector is fastened to the register circuit board, an output circuit board is selected to provide the desired signal connections and signal processing, and said output circuit board is positioned and connected between said base and said current module and said register circuit board.

55. The method of fabricating and subsequently customizing an electronic energy meter of claim 54 wherein said selected output circuit board is detachably connected by positioning the connector on the bottom of said output circuit board in position with said connector receptacle in said base and rotating the top of said output circuit board about said connector receptacle until a connector at the top of said output circuit board is connected to said edge connector of said register circuit board.

56. The method of fabricating and subsequently customizing an electronic energy meter of claim 55 wherein a projection is provided on said planar support member and a mating aperture is provided in said output circuit board, and when the top of said output circuit board is rotated toward said edge connector said slot extends through said mating aperture to position said output circuit board across the periphery of said electronic energy meter.

57. The method of fabricating and subsequently customizing an electronic energy meter of claim 48 wherein an electromagnetic and thermal shield is slid down over said register assembly module and past said voltage module onto a circular step molded in said base to closely surround said register assembly module and retain said output circuit board in place.

58. The method of fabricating and subsequently customizing an electronic energy meter of claim 57 wherein said electromagnetic and thermal shield is stamped to provide a plurality of resilient spring fasteners around the central circumference thereof which grip said planar support member when said electromagnetic and thermal shield is slid into position.

59. The method of fabricating and subsequently customizing an electronic energy meter of claim 58 wherein said electromagnetic and thermal shield is fabricated from sheet ferrous material into a tapered tube with tabs extending from one axial edge under the other axial edge, and said tabs are welded in place.

60. The method of fabricating and subsequently customizing an electronic energy meter of claim 59 wherein a transparent housing is positioned over said register assembly module and slid over said voltage module and secured to said base.

61. The method of fabricating and subsequently customizing an electronic energy meter of claim 48 wherein an electromagnetic shield is positioned around said voltage module extending from said register assembly module to said base, an aperture is provided in said electromagnetic interference and thermal shield, and a bar code is positioned behind said aperture on said voltage module defining the customized voltage and current modules, and optically reading said bar code to identify ratings of said meter.

62. The method of fabricating and subsequently customizing an electronic energy meter of claim 61 wherein optically reading the bar code is used to control the testing procedures applicable to that customized combination of modules.

63. The method of fabricating and subsequently customizing an electronic energy meter of claim 61 wherein said base includes an upwardly extending angular positioning member adjacent the bottom of said electromagnetic and thermal shield, and said electromagnetic and thermal shield includes a cutout wherein said cutout is positioned about said positioning member to position said aperture in said electromagnetic and thermal shield adjacent said bar code to enable viewing of said bar code through said aperture.

64. The method of fabricating and subsequently customizing an electronic energy meter of claim 63 wherein said cutout is in the order of twice the angular length as said angular positioning member and said electromagnetic and thermal shield is rotated until one end of said cutout contacts one end of said angular positioning member to position said aperture in said electromagnetic and thermal shield adjacent said bar code to enable viewing of said bar code through said aperture.

65. The method of fabricating and subsequently customizing an electronic energy meter of claim 64 wherein said rotation of said electromagnetic and thermal shield rotates said plurality of resilient spring fasteners on said electromagnetic and thermal shield to grip said planar support member.

66. The method of fabricating and subsequently customizing an electronic energy meter of claim 64 wherein said angular positioning member is provided in said circular step.

67. The invention as defined in any of the preceding claims including any further features of novelty disclosed.