CA1291213C - Circuit condition monitoring system - Google Patents
Circuit condition monitoring systemInfo
- Publication number
- CA1291213C CA1291213C CA000561664A CA561664A CA1291213C CA 1291213 C CA1291213 C CA 1291213C CA 000561664 A CA000561664 A CA 000561664A CA 561664 A CA561664 A CA 561664A CA 1291213 C CA1291213 C CA 1291213C
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- Canada
- Prior art keywords
- test point
- connector
- electrically
- point socket
- circuit condition
- Prior art date
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Abstract
CIRCUIT CONDITION MONITORING SYSTEM
Abstract of the Disclosure A circuit condition monitoring system for an electrical power distribution system includes a system connector component having an integrally molded test point socket within which a circuit module is received to provide fault current or voltage loss monitoring of a system conductor within the connector. The test point socket provides capacitive coupling to the monitored conductor without the use of a metallic test point, and a ground return to the electrically conductive outer sheath of the connector. An electrically conductive end cap may be provided to cover the projecting end of the module when the module is installed in the socket. Adapters installed on the other end of the module enable the module to be installed on prior metallic contact-type test points.
Abstract of the Disclosure A circuit condition monitoring system for an electrical power distribution system includes a system connector component having an integrally molded test point socket within which a circuit module is received to provide fault current or voltage loss monitoring of a system conductor within the connector. The test point socket provides capacitive coupling to the monitored conductor without the use of a metallic test point, and a ground return to the electrically conductive outer sheath of the connector. An electrically conductive end cap may be provided to cover the projecting end of the module when the module is installed in the socket. Adapters installed on the other end of the module enable the module to be installed on prior metallic contact-type test points.
Description
SPECIFICATION
Backqround of the Invention The present invention i~ directed generally to circuit condition monitoring system~ for power distribution systems, and more particularly to a connector component for such sy~tems haYing an integral test point socket for receiving a circuit condition te~t module.
In the operation of electrical power distribution sy6tems it i~ frequently neces&ary to monitor circuit parameter~ ~uch as current and voltage at a particular location to detect the occurrence of a fault current or 108 of voltage at the location. To thl6 end, distribution sy~tems have been provided with te~t point~ at variou~
locations by ~ean~ of which monitoring devices such a~ fault indicators are capacitively coupled to conductors of the ~y8tem8. Typically, such test points are in the fo~m o~
expoRed metallic contacts imbedded in the houslng of a sy6tem connector component, such a~ elbow-typ~ connectors illu~trated, fo~ e~ample, in ~.S. ~atents 4,263,5S0 and 4,375,617 of the present inventor, and available comme~cially, for example, as the El~timold type 376LR
connector, or similar connector manufactured by ~TE
Corporation~ Such elbow connectors are typi~ally used for connectlng a ~ystem cable to the terminal o a system component, such A~ a trans~orner Qr relay.
V~rlou~ typ&~ of circult conditlon indic~ting modules have bean in~t~lled on ~uch test polnts, includin~, * Trade-mark ~f Elastimold Division of ~merace Corp.
~ 2 ~ ~
for example, fault indicators as described in U.S. Patents 4,234,847, 4,438,403, 4,424,512 and 4,458,198 of the present inventor, and voltage indicators a~ described in U.S.
Pa~ent~ 4,152,643, 4,251,770, 4,550,288 and ~,641,220 of the s present inventor.
One drawback of prior test point constructions i~
the use of the metallic contact on the surface of the connector. Thi~ not only increases the c08t of manufacture of the te&t point, but also creates a need to c~p the contact when the test point was not in use to avoid the perception of a shock hazzard. The pre~ent invention provides a sy~tem for monitoring Yoltage and/or current on a system conductor which by providing a test point 80 cket of novel construction avoids the need for an exposed metallic contact and the attendant complexity of con~truction. The system further provides a circuit condition monitoring module which can be installed on prlor metallic contact-type te~t points as well as on te6t point ~ockets constructed in accordance with the invention, and which in at least one embodiment completely avoid~ the need for exposed contacts on the module housing thereof.
Summar~ o~ the Invention The lnventlon i~ dlrected to a connector ~or establishing a monitored electrical connection between electrical terminal~ of component~ of an electrical power distribution sy~te~. Tbe connector inQlude~ A connectox body ~ormed o~ electric~lly non-conductive material, fir~t a3 and second terminal means fo~ electrically and mechanically engaging the electrical terminals of the componen~s, electrical conductor means e~tending within the body portion between the first and second terminal means for providing an electrical current path therebetween, the conductor mean6 being ~ubstantially ~urrounded by the body portion, and a sheath formed of an electrically-conductive material overlying the surface of the body portion. A recess forming a te~t point socket i~ defined on the outside surface of the connector for receiving a circuit condition indicatinq module, the ~idewalls of the socket being formed primarily of the electrically-conducti~e material of the ~heath, and at least a portion of the bottom of the te~t point socket being formed of the non-ele~trically conductive material of the connector body, whereby the monitoring module when received within the test point socket i8 capacitively coupled to the monitored conductor.
The invention is further directed to a circuit condition monitoring system for an electrical power 20 di~tribution system for providing a monitored connection between the terminals of electrical componentfi of the distribution system. The system comprises a connector body Pormed of electrically non-conductive material, ~irst and ~econd terminal means for electrlcally and mechanic~lly engaging the electrlc~l termlnal~ o~ the ~ystem componenta, electrical conductor me~n~ extending withln the body between the first and second terminal means for providing an ~29~2~3 electrical current path therebetween, said conductor means being substantially ~urrounded by the ~ody portion, and a sheath formed of an electrically-conductive material overlying ~he surface of the ~ody portion. A re~es~ i defined on the curface of the connector form6 a test point socket for receiving a circuit condition indicating module, the sidewalls of the socket being formed primarily of the electrically-conductive material of the sheath, and at least a portion of the bottom of the test point 60cket being formed of the non-electrically conductive material of the connector body whereby the monitoring module when received within the te~t point socket i8 capacitively coupled to the monitored conductor. A circuit condition monitoring module operable from a capactitive coupling to the conductor and a ground return connection i8 provided. The module includes a capacitive coupling plate at one end for interacting with the coupling means, and ground coupling means o~
establishing a ground return connection~ m e te~t point 60cket i5 dimensioned to receive the module with the one end thereof extending directly toward the conductor means, and the ground coupling means coupling to the 6idewall of the test point socket, whereby, in the presence of an alternating voltage on the conductor, a voltage i8 induced within the module.
A circuit condltion mon1toring module for in~tallation in ~ te~t p41nt 80cket havlng a 8id2-wnll a~
least partially electrlcally conductlve and connected to ~ 2~ ~
ground, and a bottom end at least partially electrically non-conductive, and in proximity to a monitored electrical conductor, comprise~ a circuit condition monitority circuit operable fram ~n applied ~lternating voltage, a housing S formed of electrically non-conductive material for containing the circuitry, the housing being dimen~ioned to fi~ within the test point socket with an interior end thereof adjacent the bottom end, a first capacitive coupling element within the hou~ing at the interior end thereof for electrically coupling the monitoring circuit to the monitored conductor, and ground return coupling means for electrically coupling the monitorlng circuit to ground whereby the circuit is powered by alternating current on the monitored conductor.
Brie _ DescriE~tion of the Dra_~gs The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reerence to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numeral~ identiPy like elements, and in which:
Figure 1 1~ a ~ide elevational view partially in flection oP an elbow type connector including a te~t point ~ocket and in~t~lled ~ault indic~tor module con~tructad in accordance wi~h the inv~ntion.
~ 2 ~ ~
Figure 2 i8 a cro~s-sectional view of the front of the elbow connector taken along line 2-2 of Figure 1.
Fi~ure 3 i~ an enlarged exploded perspective view showing the test point socket, fault indica~or ~odule and psotective end cap of the circuit condition monitoring ~ystem of the invention.
Figure 4 is an enlarged cross-sectional vie~
~howing the test point socket and installed fault indicator module of the elbow connector of Figure 1.
Figure 5 is an enlarged exploded perspective partially fragmented view ~hcwing the faul~ indicator module and protective end cap of Figure 3 combined with an adapter sleeve for installation on a conventional prior design metallic contact-type test point.
Figure 6 is a side elevational view partially in section showing a conventional elbow connector of prior con~truction w~erein a fa~lt in~icator module, pr~tective end cap and adapter ~leeve have been in~talled in accordance with the invention~
Figu~e 7 is an enlarged cross-sectional view showing the ~ault indicator module, protective end cap and adapter sleeve of Figure 6.
Figure 8 i8 a side elevational view partially in ~ection showing a conventional elbow connector of alternate prior con~truction to that ~hown in Figure 6 wherein a ault lndicator ~odul~, protectl~& end cap and ~lternnte adapt~r ~leeve have been in~talled ~n accordance with tha invention.
Figure 9 i8 an enlarged cross-sectional view of the fault indicator module, pro~ective end cap and alternate adapter sleeve shown in Figure 8.
Figures lOa and lOb are diagrammatic vi~w~ of the princip~l components of the indicator flag as~embly of the fault indicator module in a reset state.
Fi~ure~ lla and llb are diagrammatic views similar to Figures lOa and lOb, respectively, showing the principal components of the indicator flag assembly in transition between a reset state and a trip state.
Figure 12a and 12b are diagrammatic views similar to Figure lOa and lOb, respectively, showing the principal components of ~he indicator flag assembly in a trip state.
Figure 13 i8 an electrical schematic diagram of the circuitry of the fault indicator module of Fi~ures ,,_9.
Figure 14 is an exploded perspective view aimilar to Figure 3 showing an alternate construction for a fault indicator module constructed in accordance wi~h the invention.
Figure 15 i8 an enlarged cross-~ectional view of the fault indicator module of Figure 14~
Figure 16 is a ~ros~-sectional view of a test adapter for ~ test polnt socket constructed in accordance with the invention~
Flgure 17 ia ~ cros~-secti~nal viæw of a plug for in~erting in a te~t point 60c~et constructed in accordance with the invention.
Figure 18 i8 a cros6-sectional view o an alternate construction for a te~t point socket constructed in accordance with the invention.
cription of the Preferred ~mbodiment Referring to the drawings, and particularly to Figures 1-4, a plug-in type elbow connector for use in high voltage alternating current power distribution ~yR~em~ for establi6hing a plug-in connection to a tran~former or other ~ystem co~ponent (not shown) i~ identified generally by reference n~1meral 10. AB 6hown, the connector 10 includes generally a conductor 11 extending generally axially through an electrically non-conductive body portion 12 encaRed in an electrically-conductive sheath 13, the ~heath being grounded in accordance with conventional practice. An electrically-conducti~e contact me~ber 1~ extend6 from condu~t~r 11 ~o mate with a complementary contact on the associated system component. An arcuate member 15 having ends anch~red in the conductive sheath 13 extends from the connector to receive the hooked end of a lineman's tool. The axial conductor 11 i~ connected, in accordance with conventional practice, to the conductor 16 of a flexible cable 17 o~ the type commonly utilized in power di~trlbution 8y8tem8. A layer 17'of semi-conductive material may ~e provided around conductor 11 to provide 0t~e~a relle~ within the conductQ~ ln a aanner well known to tbe art, .
To provide for detecting fault cuerents or voltage lo~s in conductor 11 connector 10 includes, in accordance witb the invention, a test poin~ socket 18 for receiving a circuit condition indicating module. in this ca~e a fault indicator module 20. The te~t point socket 18 may preferably be formed by a portion of the electrically-conductive outer sheath 13 ~hich projects radially from the central axis of a central body portion of the connector. In particular, this projecting po~tion 21 i8 preferably cylindrical in form and of an axial extent such that the depth of test point ~ocket 18 i~ approximately half the length of fault indicator module 20~ Thus. when module 20 i8 ~eated in the test point socket 18 as shown in Figure 4 approximately half of the module is received within the socket. Since test point socket 18 is formed by the el~ctrically conductive sheath 13 the Ridewalls of the socket are electrically conductive. Howe~er, since sheath 13 does not extend across the bottom of socket 18 the botto~
of the socket i8 not electrically conductive.
The ~ault indicator module 20, which is representative of variou o~her typeR of circuit condition monitoring modules which can be u~ed in conjunction with the te~t point ~ocket, i8 seen to include an electrically non-conducti~e tran~parent plastic hou~ing 22 withln which the electrical CQmponents o the Pault indlcator are aonta~ned~ In pArticu~ar, within hou~lng 22 tha fault indicator module include3 a disc-~haped in~ulator board 23 ~ -3 positioned perpendicularly to the axis of the housing at a location intermediate the ends thereof, and a layer 24 of epoxy material at the in~ide end of the hou6ing for ~ecurin~
the insulator board in place. Additional electrical S components included in housing 22 include a first capacitive coupling elemPnt in the form of a metallic plate 25 for capacitively coupling the circuitry of the fault indicator to conductor 11, a reed switch 26 for sensing the occurreDce of a fault current in the conductor, an electro-mechanical indicator flag assembly 27 for vi~ually indicating the occurrence of a fault current through the transparent outside end of hou~ing 22, and a magnetic winding assembly 28 for actuating the indicator flag asse~bly.
The fault indicator module 20 may be protected by an electrically~conductiYe ~emi-flexible rubber end cap 30 which i8 dimensioned to slide over the projecting out~ide end of module housing 22. The axial length o~ end cap 30 i8 such that when the end cap is fitted over housing 22 a~
shown in Figure 4 and the module is seated in te~t point socket 18, the rim por~ion 31 of cap 30 is caused to engage the rim portion 32 of the test point socket. To this end, rim portion 31 may include an annular overlying flange which ~lides over a complementarily dimensioned underling flange on rim portion 32, as best s~own in Figure 4~ A window 33 in end ~p 30 ~llows the u~er to vlaw lndicator flag a~embly 27 th~ough the transparent ~nd 34 o~ hou~i~g 22.
tab portion 35 at the clo~ed end of end cap 30 having an aperture 36 therethrouqh i~ provided to facilitate the removal of the fault indicator module from connector 10 with a conventional lineman' 8 tool.
Operating power for the circuitry of fault S indicator module 20 i~ derived from conductor 11 by means of the metallic plate 2~, which when module 20 iB seated in te~t point ~ocket 18 i8 sufficiently clo~ely spaced to the conductor to provide a level of capacitive coupling whereby adequate alternating voltage i8 derived from the conductor for operation of the fault indicator circuitry. A necessary ground return for thi~ circuitry may be provided, as shcwn in Figures 1-5, by an electrical conductor 37 which extends through the ~idewall of hou~ing 22 and along the out~ide ~idewall of the housing~ When housing 22 i8 seated in test point socket 13 conductor 37 i8 brought into electrical communication with the electrically-conductive sidewall o~ -the socket, thus establishing the ground return through the electrically grounded sheath 13 of ~he connector.
By rea~on of the novel construction of test point soeket 18, connector 10 is manufactured without the use of a metallic contact member such as utili~ed in prior connector constructions. In~tead, the connector has on its exterior surface only the te~t point socket formed of electrically-conductiYe rubber sheath material. Since sheath 13 does not extend acros~ the bottom of the socket any aircuit condltion ~onitoring modul~ (~uah ~8 ~ault lndicator module ~0) ~eated in the socket 18 automatlcally coupled by means o~ lts ~ 3 internal metallic plate 25 to conductor 11. The surrounding electrically-conductive sheath material of the ~leeve portion 21 o~ the test point socket provides an efficient ground return path which ~ay conveniently e~tablished by either an exposed conductor, such as conductor 37 on the exterior of hou~ing 22, or by a second capacitive coupling element, as will be di~cribed in connection with ~igures 14 and 15.
In accordance with another aspect of the invention, the same circuit condition monitoring module 20 and protective end cap 30 utilized in conjunction with test point socket 18 can be utilized in conjunction with prior connectors using a metallic-contact type te~t point. To this end, the monitoring system of the invention utilizes, as shown in Figures 5-7, an adapter sleeve 40 which i~
dimen~ioned to fit over the inside end of housing 22 and extend between en.d cap 30, when installed on the housinq, and the metallic te~t point 41 of a prior connector 42. As be~t shown in Figure 7~ connector 42 includes a conventional metallic contact 43 which is exposed at test point 41 to provide capacitive coupling to a conduotor 44. Contact 43 forms an annular flange at test point 41. The adapter sleeve 40, which i8 formed of electrically-conductiYe rubber, include~ an electrically non-conductive lnterior ~5 ~leeve insert 45 which engage~ the annular ~lang~ of contact 43 ~o ~ain~Ain th~ adapter ln po~ition.
The ~dequate ~xcita~ion for the ~ault indicator module circuitry i8 obtained, in accordance with the invention, by capacitiYe coupling between metallic plate 25 and embedded con~act 43, and between the embedded contact and conductor 4~. The conductive body portion of sleeve 40 5 i8 in contact with the electrically conductive ~heath 46 of connector 42 to prvvide a ground return path for fault indicator module 20 in the manner previously described. The non-conductive interior sleeYe 45 preven~ contact 43 from ~eing grounded to the body of ~leeve 40. An a~nular rim portion 47 on 61eeve 40 engage~ the rim portion 31 of end cap 30 when module 20 i8 installed on the test point, as shown in Figures 6 and 7.
By reason of the u~e of other adapter sleeves other prior te6t point constructions can be accommodated ~y the circuit condition module of the invention. For example, in Figures 8 and 9 an alternate prior test point conatruction i8 shown wherein a connector 50 having a central conductor 51 has a generally washer-shaped metallic contact 52 embedded in a projecting test point portion 53 of the connector. In this in~tance, an alternate ~orm of sleeve-shaped adapter 53 engages a rim portion 54 molded into the connector hou~ing. No connection i 8 made between the adapter ~leeve 53 and contact 52. An annular rim portion on the sleeve a~sures a secure engagement ~ith connector 50 and the nece~sary ground retu~n path i8 e~tabll~hed th~ough the ~l~cttically conductive sheath SS o~
the connector. A~ be~ore, adequate AC exaitRtlon fo~ the ~ 3 fault indicator module circuitry i8 achievedin accordance with the invention, by capacitive coupling between the metallic plate 25 and the embedded contact 52, and between the embedded contact and conductor 51 of connector 50O
S With the Pxception of the provision of ~pecific for coupling to a monitored conductor and to ground, fault indicator module 20 may ~e conventional in con6truction and operation. In particular, to provide an indication of the occ~rrence of a fault current in conductor 11, the fault indica~or includes, as part of the previously identi~ied flag indicator a~sembly 27, a disc-shaped target 65 ~hich i~
mounted for rotation on a plvot 65. The ~ace of the target disc ha~ a red segment 65a ~Figures 10-12) and a white segment 65b, only one of which i~ visible at a time through window 33 and the transparent end 34 of housing 22.
Secured to and pivotal with target 65 is a targe~
permanent magnet 70, which i~ ~ormed o~ a magnetic material having a high coercive ~orce, such as ceramic, and i8 magnetically polarized to form two magnetic pole~ of opposite gender, as indicated in Figure~ 10-12, with opposite magnetic polaritieE along a diameter of the magnet.
The target di~c 65 and its permanent magnet 70 are biased to the position ~hown in Figures lOa and lOb when the fault indicator is in ~ non-tripped or reset condition ky mean~ of a stationary uw~haped mngnettc pole piece 71, whlch i~
prc~erabl~ ormed o~ a magnetlc mate~ial havlng a relatlvely low coercive forca, ~uch as a chrome ateel.
When ~he fault indicator i8 in a reset state, the projecting ends of the pole piece are bia~ed ~o the magnetic polarities indicated in Figures 10a and 10b. As a re~ult.
the opposite polarity magnetic pole~ of the target magnet 70 are attracted to position the target disc 65 as shown. In thi~ po~ition the red segment 65a of the target disc i~ not vi~ible through window 33, and all that is seen is the whi~e segment 65b.
On the occurrence of a fault current in conduc~or 11, which fault current may, for example~ exceed 400 amperes, pole piece 71 i8 remagnetized to the magnetic polarities shown in Figures 11 and 12 by momentary energization of a trip winding 72 on the center section of the pole piece. As a result, the poles of magnet 70 ~re repelled by the adjacent like gende~ pole~ ~f the pole piece and the target disc i8 caused to rotate 18Q to the tripped position shown in Figure~ 12a and 12b. In this position.
the red ~e~ment 65a o~ the target disc i8 visible through window 33, and a lineman viewing the ~ault indicator i8 advised that ~ fault current has flowed ~hrough conductor 11 .
The target dlsc remains in the fault indicating po~ition until the end~ of pole piece 71 are subsequently remagnetized to the magnetic polarities shown in Figures lDa ~5 and 10b ~y momentary energi2atlon o~ A reset windlng 73 on the ent~r ~ectiQn ~f ~he polc piece. A~ a ra~ult, the target ma~net 70, and hence the target di~c 65, ~re causea ~ 3 to rotate from the tripped position ~hown in Figure 12 to the re~et position sh~wn in Figure 10 and the fault indicator i8 conditioned ~o respond to a ~ub~equent fault current.
~nergization of winding 72 upon occurrence of a fault current in conductor 11, and energization of winding 73 upon restoration of current in conductor 11 following a fault, i8 accomplished by mean6 of circuitry contained within the fault indicator housing 22. Referring to the schema~ic diagram shown in Figure 13, windings 72 and 73 are connected end-to-end for independent energization upon occurrence of fault and re~et conditions, re~pectively.
Operating power for these windings is o~tained by means of a bridge rectifier network 80, con~iRting of diodes 81-84 .
One input terminal R thi~ network, formed at the juncture of the anode of diode 81 and the cathode o~ diode 82, i8 connected to the capacitive coupling pla~e 25. The othe~
input terminal, formed at the juncture of the anode of diode 83 and the cathode o~ diode 84, is coupled to ground through ~o the electrically conductive sheath 13 of connector 10, either by direct connection, as shown in Figures l-S, or by capacitive coupling, as shown in Figure 18. With this arrangement, high voltage alternatlng current carried in conductor 11 is c~pacitively coupled to the brldge recti~ier network, re~ulting in the productlon of a pulsatlng unidlrectional curr~nt ~t the output tarminal~ Q~ the neSwork.
The positive polarity output terminal of the bridge rectifier network, formed at the cathode~ of diodes 81 and 83, i~ connected to one contact of a reed switch 26, to the end termina~ 8 of winding~ 72 ~nd 73, and to 5 respective terminals of capacitors 87 and 88. m e negative polarity output terminal of the bridge rectifier network~
formed at the juncture of the anode of diodes 82 and 84, i8 connected directly to ~he remaining terminal of capacitor 87, and through a forward-biased diode 89 to the remaining terminal of capacitor 88. With this arrangement, capacitors 87 and B8 are charge~ by the pulsating unidirectional current developed by bridge rectifier network 80 in the presence o~ voltage on conductor 11.
To provide for periodic energization of reset winding 73 during normal current flow in conductor 11, the remaining end term~nal of winding ~3 i8 connected through a ~ilicon controlled rectifier (SCR) !~0 to the negative polarity terminal of capacitor 87. Periodic conduction through SCR 90 i8 obtained by connecting the gate electrode of that device to the positive polarity output terminal of bridge rectifler network 80 through a re6istor 91 and a bilateral diode 92, and to the cathode of SCR 90 by a resistor 93. With this arrangement, SCR 90 i8 periodically triggered into conduction when the voltage developed across bilateral diode 92 as a resul~ of capacitor 87 being charged by bridge reatifier B0 xeaches the threshold level of the bilateral diode.
~ 2 In operation, under normal current flow conditions, the vol tage developed acros~ capacitor 87 as the capacitor is charged by bridqe rectifier network 80 .progressively increases wi~h time, until the threshold ~reakdown voltage of bilateral diode 92 i~ reached, at whi~h time SCR 90 is triggered and capacitor 87 discharges through winding 73. Diode 89 prevents capacitor 88 from being di~charged through SCR 90 and winding 73, leaving the capacitor available for energizing winding 72 in response to a fault condition. In practice, the breakdown voltage of bilateral diode 92 may be in the order of 34 volts, and the time required for capacitor 88 to reach thi~ threshold level with a voltage level of 4,4~0 Yolts on conductor 11 may be approximately 2 minutes. In any case, the voltage level within conductor 11 is not critical to the operation o~ the reset circuit, and ha6 only the ~ffect of changing the frequency of the re~et ~yc}e.
Trip winding 72 i~ energized upon occurrence of a fault current in conductor 11 by discharge of capacitor 88 through a ~econd silicon controlled rectifier 100.
Conduction i8 established through SCR 100 by closure of the contacts of reed switch 26, which i~ positioned within housing 22 so as to be in proximity to conductor 11 when tbe module i8 seated in te~t socket 18. The gate electrode o~
SCR 100 ls connected through a bilateral diode 101 and re~i~tor 102 to the cQnt~ct~ of ~eed swltch B6, and by ~
~esistor 103 to the SCR cathode. ~he ~uncture o~ re~istor ~_f2~1.2 J_~3 and bilateral diode 104 i8 connected by a capacitor 104 to capacitor 88.
Upon occurrence of a fault current in conductor 11, the positive polarity output terminal of bridge rectifier network 80 i5 connected thro~gh the then closed contacts of reed fiwitch 26 and the circuit comp~i~ing resi~tor 102, bilateral diode 101, re~istor 103, and capacitor 104 to the gate electrode of SCR 100, cau~ing that device to be rendered conductive following a predetermined time delay. At this time ~apacitor~ 87 and 88 are caused to discharge through SCR 10~ and energize winding 82. The resulting magnetic f1UY in the ~-shaped pole piece 71 reverses the magnetic pole polaritie~ of the pole piece and causes rotation of the taryet as previously de~cribed.
To avoid the possibility of rotor 85 becoming stalled upon reversal of the ~agnetic polarities o~ pole piece 71, as might happen with a rotor being perfectly centered between the poles of pole pieces 71 and having a degree of bearing f riction, the ~ault indicator includes an auxiliary U-shaped pole piece llQ positioned adjacent target means 70 coaxial with and at an angle to pole piece 71.
The existence of a magnetic field betwePn the poles of pole piece 71 results ln the productlon of induced magnetic pole~ on auxiliary pole piece 110 of opposite gender to the mo~t adjacent pole~ of pole ple~e 71~ Thi~ i8 illustrated ln Fi~ure~ 10-1~ and ra~ult~ ~y rea~on of the auxlliary pole piec~ llC beco~ing included in he magnetlc l2~3 flux path between the poles of pole piece 71. The effect of the induced magnetic pole6 ic that upon rever~al of the gender of the poles of pole piece 80 following occurrence of a fault current the auxiliary poles exert a rotational force on the most adjacent poles of the permanent rotor magnet 70 as~ociated with target 65. Thi~ results in a rotational moment being exerted on the target, tending to turn the target in a predetermined ~counter-clockwise in Figure~
10-12) direction such that the target i8 pre~luded fr~m remaining in its reset po~ition, even if it should be perfectly positioned and have a degree of bearing friction.
Once rotation has been establi6hed, as shown in Figure 11, the greater force of the main pole piece 71 overcomes the effect of the auxiliary pole piece 110 and rotation continues until the target i8 aligned as shown in Figure 12.
Other fault indicator circuit~ having different or additional operating features, such a~ the fault indicator circui-ts described in the U.S. Patents Nos. 4,795,982 and 4,686,518 may be utilized in place of the circuit shown by replacing the prior spring contact metallic coupling element with a capacitive coupling element, and adapting the ground return means in accordance with the intended use.
In an alternative embodiment o~ the in~ention '~ ~.2 ~
~hown in Figures 14 and 15 the external wire 37 utilized to establi~h electrical communication with the ~idewall of test point 60cket 18 i8 replaced by a second capacitive coupling element in the form of a bras~ ring or cylinder 106 on the S inside surface of housing 22. Thi8 ring capacitively couples the fault indicator circuitry through the hou~in~
wall to the electrically conductive socket sidewall 21 and the overlying cap member 30, which are connected to yround through sheath layer 13. Thu~, the requisite ground return path i~ establi~hed without an external contact on the housing. Since the coupling to conductor 11 is also obtained in accordance with the invention, without an ex~ernal contact the fault indicator module is desirably entirely free of exposed contacts.
While a ring-shaped coupling element 106 has been shown, it will be appreciated that other construction~ for thi~ element are possible, including a single plate positioned against the inside surface of the module housing opposite ~idewall 21.
As shown in Figure 15, should an electrically conductive surf ace be desi red on the bottom wall 107 of test point ~ocket 18 for any reason, it would ba possi~le to deposit or otheewise apply a thin resistive coating lOB
formed of a conductlve paint or rubber on the bottom wall 107 providad ~uch coating does not contact the electrically conductive ~idew~ 21 o~ the socket.
In certain appllcatlon~, such as where te~t z~
equipment i8 to be temporarily coupled to a monitored conductor, a contact a~sembly 110 can be temorarily in~erted in test point 30cket la to provide a metallic test point ~o which the in~trumentation can be connected. In particular, as shown in Figure 16, the contact assembly may include a body 111 formed of electrically non-conductive rubber dimensioned to fit within the ~ocket. A metallic capacitiYe coupling element in the form of a plate 112 is positioned within the body 80 as to couple to conductor 11, while avoiding contact with the electrically conductive sidewalls of the socket. A combination electrical terminal and hook member 113 extends axially within housing 111 from plate 112 ~o a location external to the housing, where it can be connected to or used to install or remove the contact 1~ as~embly.
When the te~t paint socket i8 not in u~e it may be desirable to install a plug member in the socket. This not only prevents the collection of dirt in the socket, but al~o eliminates any perception of a shock haza~d from the exposed bottom wall of ~he hou~ing. As shown in Figure 17, the plug member, generally designated 120, may comprise an electrically conductive rubber body 121 have a rim portion formed therein Por engaging the rim portion 3~ of test point socket 18, and a projecting handle portion 1~3 having an aperture 124 ~or enga~ement ~ith the hook end of a conventional llneman'~ tool~
In a further modificatlon of the invention sho~n ~ 3 in Figure 18, the coupling between the fault indicator circuit and monitored conductor 11 i8 increa~ed by formin~
test point socket 18 partially in the body portion of the connector. Consequently, when the fault indicator is seated in the body portion 125 of the socket, against the recessed bottom surface 126, the capacitive couling plate 25 of the module i8 positioned clo~er to conductor 11. A11 other construction feature~ of the invention may remain unchanged, and the alternate constructions of Figure~ 14 and lS, the test adapter of ~igure 16 and the elec~rically conductive cap member 121 remain applicable.
The components of the circuit condition monitoring ~ystem of the invention may be manufactured using conventional technique and material~. In particular, connector 10 may have an insulating layer formed of EPDM
material and conductive sheath formecl of the same material impregnated with carbon. The module housing may be ~ormed of Lexan (Trademark o~ General Electric Compan~) or an acrylic, and the end cap and adapter may be formed of a carbon-impregnated EPDM rubber.
Thu8, a ~ystem ha~ been ~hown which incorporate6 a novel teRt point socket in a connector by which various circuit condition monitoring modules can be brought into elect~ical communication with a monitored conductor without the need ~or provlding expo~ed electrical contacts ~or ~ecuring capacitiv& coupllng tQ the conductor. Moreover, novel cons~ruction for the circuit condition monitoring ~t~ 3 module ha~ been shown which enables the module, when used in coniunction with appropriate adapter sleeves, to be installed on either a test point socket constructed in accordance with the invention, or on a prior te~t point construction of the type having an exposed metallic contact.
No change~ are required in the module and the need for exposed contact~ on the module is obviated in favor of internal capacitive coupling means.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that change~ and modifications may be made therein without departing from the invention in its broader aspects, and, therefore, the aim in ~he appended claims is to cover all such changes and modification~ as fall within the true spirit and ~cope of the invention.
Backqround of the Invention The present invention i~ directed generally to circuit condition monitoring system~ for power distribution systems, and more particularly to a connector component for such sy~tems haYing an integral test point socket for receiving a circuit condition te~t module.
In the operation of electrical power distribution sy6tems it i~ frequently neces&ary to monitor circuit parameter~ ~uch as current and voltage at a particular location to detect the occurrence of a fault current or 108 of voltage at the location. To thl6 end, distribution sy~tems have been provided with te~t point~ at variou~
locations by ~ean~ of which monitoring devices such a~ fault indicators are capacitively coupled to conductors of the ~y8tem8. Typically, such test points are in the fo~m o~
expoRed metallic contacts imbedded in the houslng of a sy6tem connector component, such a~ elbow-typ~ connectors illu~trated, fo~ e~ample, in ~.S. ~atents 4,263,5S0 and 4,375,617 of the present inventor, and available comme~cially, for example, as the El~timold type 376LR
connector, or similar connector manufactured by ~TE
Corporation~ Such elbow connectors are typi~ally used for connectlng a ~ystem cable to the terminal o a system component, such A~ a trans~orner Qr relay.
V~rlou~ typ&~ of circult conditlon indic~ting modules have bean in~t~lled on ~uch test polnts, includin~, * Trade-mark ~f Elastimold Division of ~merace Corp.
~ 2 ~ ~
for example, fault indicators as described in U.S. Patents 4,234,847, 4,438,403, 4,424,512 and 4,458,198 of the present inventor, and voltage indicators a~ described in U.S.
Pa~ent~ 4,152,643, 4,251,770, 4,550,288 and ~,641,220 of the s present inventor.
One drawback of prior test point constructions i~
the use of the metallic contact on the surface of the connector. Thi~ not only increases the c08t of manufacture of the te&t point, but also creates a need to c~p the contact when the test point was not in use to avoid the perception of a shock hazzard. The pre~ent invention provides a sy~tem for monitoring Yoltage and/or current on a system conductor which by providing a test point 80 cket of novel construction avoids the need for an exposed metallic contact and the attendant complexity of con~truction. The system further provides a circuit condition monitoring module which can be installed on prlor metallic contact-type te~t points as well as on te6t point ~ockets constructed in accordance with the invention, and which in at least one embodiment completely avoid~ the need for exposed contacts on the module housing thereof.
Summar~ o~ the Invention The lnventlon i~ dlrected to a connector ~or establishing a monitored electrical connection between electrical terminal~ of component~ of an electrical power distribution sy~te~. Tbe connector inQlude~ A connectox body ~ormed o~ electric~lly non-conductive material, fir~t a3 and second terminal means fo~ electrically and mechanically engaging the electrical terminals of the componen~s, electrical conductor means e~tending within the body portion between the first and second terminal means for providing an electrical current path therebetween, the conductor mean6 being ~ubstantially ~urrounded by the body portion, and a sheath formed of an electrically-conductive material overlying the surface of the body portion. A recess forming a te~t point socket i~ defined on the outside surface of the connector for receiving a circuit condition indicatinq module, the ~idewalls of the socket being formed primarily of the electrically-conducti~e material of the ~heath, and at least a portion of the bottom of the te~t point socket being formed of the non-ele~trically conductive material of the connector body, whereby the monitoring module when received within the test point socket i8 capacitively coupled to the monitored conductor.
The invention is further directed to a circuit condition monitoring system for an electrical power 20 di~tribution system for providing a monitored connection between the terminals of electrical componentfi of the distribution system. The system comprises a connector body Pormed of electrically non-conductive material, ~irst and ~econd terminal means for electrlcally and mechanic~lly engaging the electrlc~l termlnal~ o~ the ~ystem componenta, electrical conductor me~n~ extending withln the body between the first and second terminal means for providing an ~29~2~3 electrical current path therebetween, said conductor means being substantially ~urrounded by the ~ody portion, and a sheath formed of an electrically-conductive material overlying ~he surface of the ~ody portion. A re~es~ i defined on the curface of the connector form6 a test point socket for receiving a circuit condition indicating module, the sidewalls of the socket being formed primarily of the electrically-conductive material of the sheath, and at least a portion of the bottom of the test point 60cket being formed of the non-electrically conductive material of the connector body whereby the monitoring module when received within the te~t point socket i8 capacitively coupled to the monitored conductor. A circuit condition monitoring module operable from a capactitive coupling to the conductor and a ground return connection i8 provided. The module includes a capacitive coupling plate at one end for interacting with the coupling means, and ground coupling means o~
establishing a ground return connection~ m e te~t point 60cket i5 dimensioned to receive the module with the one end thereof extending directly toward the conductor means, and the ground coupling means coupling to the 6idewall of the test point socket, whereby, in the presence of an alternating voltage on the conductor, a voltage i8 induced within the module.
A circuit condltion mon1toring module for in~tallation in ~ te~t p41nt 80cket havlng a 8id2-wnll a~
least partially electrlcally conductlve and connected to ~ 2~ ~
ground, and a bottom end at least partially electrically non-conductive, and in proximity to a monitored electrical conductor, comprise~ a circuit condition monitority circuit operable fram ~n applied ~lternating voltage, a housing S formed of electrically non-conductive material for containing the circuitry, the housing being dimen~ioned to fi~ within the test point socket with an interior end thereof adjacent the bottom end, a first capacitive coupling element within the hou~ing at the interior end thereof for electrically coupling the monitoring circuit to the monitored conductor, and ground return coupling means for electrically coupling the monitorlng circuit to ground whereby the circuit is powered by alternating current on the monitored conductor.
Brie _ DescriE~tion of the Dra_~gs The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reerence to the following description taken in conjunction with the accompanying drawings, in the several figures of which like reference numeral~ identiPy like elements, and in which:
Figure 1 1~ a ~ide elevational view partially in flection oP an elbow type connector including a te~t point ~ocket and in~t~lled ~ault indic~tor module con~tructad in accordance wi~h the inv~ntion.
~ 2 ~ ~
Figure 2 i8 a cro~s-sectional view of the front of the elbow connector taken along line 2-2 of Figure 1.
Fi~ure 3 i~ an enlarged exploded perspective view showing the test point socket, fault indica~or ~odule and psotective end cap of the circuit condition monitoring ~ystem of the invention.
Figure 4 is an enlarged cross-sectional vie~
~howing the test point socket and installed fault indicator module of the elbow connector of Figure 1.
Figure 5 is an enlarged exploded perspective partially fragmented view ~hcwing the faul~ indicator module and protective end cap of Figure 3 combined with an adapter sleeve for installation on a conventional prior design metallic contact-type test point.
Figure 6 is a side elevational view partially in section showing a conventional elbow connector of prior con~truction w~erein a fa~lt in~icator module, pr~tective end cap and adapter ~leeve have been in~talled in accordance with the invention~
Figu~e 7 is an enlarged cross-sectional view showing the ~ault indicator module, protective end cap and adapter sleeve of Figure 6.
Figure 8 i8 a side elevational view partially in ~ection showing a conventional elbow connector of alternate prior con~truction to that ~hown in Figure 6 wherein a ault lndicator ~odul~, protectl~& end cap and ~lternnte adapt~r ~leeve have been in~talled ~n accordance with tha invention.
Figure 9 i8 an enlarged cross-sectional view of the fault indicator module, pro~ective end cap and alternate adapter sleeve shown in Figure 8.
Figures lOa and lOb are diagrammatic vi~w~ of the princip~l components of the indicator flag as~embly of the fault indicator module in a reset state.
Fi~ure~ lla and llb are diagrammatic views similar to Figures lOa and lOb, respectively, showing the principal components of the indicator flag assembly in transition between a reset state and a trip state.
Figure 12a and 12b are diagrammatic views similar to Figure lOa and lOb, respectively, showing the principal components of ~he indicator flag assembly in a trip state.
Figure 13 i8 an electrical schematic diagram of the circuitry of the fault indicator module of Fi~ures ,,_9.
Figure 14 is an exploded perspective view aimilar to Figure 3 showing an alternate construction for a fault indicator module constructed in accordance wi~h the invention.
Figure 15 i8 an enlarged cross-~ectional view of the fault indicator module of Figure 14~
Figure 16 is a ~ros~-sectional view of a test adapter for ~ test polnt socket constructed in accordance with the invention~
Flgure 17 ia ~ cros~-secti~nal viæw of a plug for in~erting in a te~t point 60c~et constructed in accordance with the invention.
Figure 18 i8 a cros6-sectional view o an alternate construction for a te~t point socket constructed in accordance with the invention.
cription of the Preferred ~mbodiment Referring to the drawings, and particularly to Figures 1-4, a plug-in type elbow connector for use in high voltage alternating current power distribution ~yR~em~ for establi6hing a plug-in connection to a tran~former or other ~ystem co~ponent (not shown) i~ identified generally by reference n~1meral 10. AB 6hown, the connector 10 includes generally a conductor 11 extending generally axially through an electrically non-conductive body portion 12 encaRed in an electrically-conductive sheath 13, the ~heath being grounded in accordance with conventional practice. An electrically-conducti~e contact me~ber 1~ extend6 from condu~t~r 11 ~o mate with a complementary contact on the associated system component. An arcuate member 15 having ends anch~red in the conductive sheath 13 extends from the connector to receive the hooked end of a lineman's tool. The axial conductor 11 i~ connected, in accordance with conventional practice, to the conductor 16 of a flexible cable 17 o~ the type commonly utilized in power di~trlbution 8y8tem8. A layer 17'of semi-conductive material may ~e provided around conductor 11 to provide 0t~e~a relle~ within the conductQ~ ln a aanner well known to tbe art, .
To provide for detecting fault cuerents or voltage lo~s in conductor 11 connector 10 includes, in accordance witb the invention, a test poin~ socket 18 for receiving a circuit condition indicating module. in this ca~e a fault indicator module 20. The te~t point socket 18 may preferably be formed by a portion of the electrically-conductive outer sheath 13 ~hich projects radially from the central axis of a central body portion of the connector. In particular, this projecting po~tion 21 i8 preferably cylindrical in form and of an axial extent such that the depth of test point ~ocket 18 i~ approximately half the length of fault indicator module 20~ Thus. when module 20 i8 ~eated in the test point socket 18 as shown in Figure 4 approximately half of the module is received within the socket. Since test point socket 18 is formed by the el~ctrically conductive sheath 13 the Ridewalls of the socket are electrically conductive. Howe~er, since sheath 13 does not extend across the bottom of socket 18 the botto~
of the socket i8 not electrically conductive.
The ~ault indicator module 20, which is representative of variou o~her typeR of circuit condition monitoring modules which can be u~ed in conjunction with the te~t point ~ocket, i8 seen to include an electrically non-conducti~e tran~parent plastic hou~ing 22 withln which the electrical CQmponents o the Pault indlcator are aonta~ned~ In pArticu~ar, within hou~lng 22 tha fault indicator module include3 a disc-~haped in~ulator board 23 ~ -3 positioned perpendicularly to the axis of the housing at a location intermediate the ends thereof, and a layer 24 of epoxy material at the in~ide end of the hou6ing for ~ecurin~
the insulator board in place. Additional electrical S components included in housing 22 include a first capacitive coupling elemPnt in the form of a metallic plate 25 for capacitively coupling the circuitry of the fault indicator to conductor 11, a reed switch 26 for sensing the occurreDce of a fault current in the conductor, an electro-mechanical indicator flag assembly 27 for vi~ually indicating the occurrence of a fault current through the transparent outside end of hou~ing 22, and a magnetic winding assembly 28 for actuating the indicator flag asse~bly.
The fault indicator module 20 may be protected by an electrically~conductiYe ~emi-flexible rubber end cap 30 which i8 dimensioned to slide over the projecting out~ide end of module housing 22. The axial length o~ end cap 30 i8 such that when the end cap is fitted over housing 22 a~
shown in Figure 4 and the module is seated in te~t point socket 18, the rim por~ion 31 of cap 30 is caused to engage the rim portion 32 of the test point socket. To this end, rim portion 31 may include an annular overlying flange which ~lides over a complementarily dimensioned underling flange on rim portion 32, as best s~own in Figure 4~ A window 33 in end ~p 30 ~llows the u~er to vlaw lndicator flag a~embly 27 th~ough the transparent ~nd 34 o~ hou~i~g 22.
tab portion 35 at the clo~ed end of end cap 30 having an aperture 36 therethrouqh i~ provided to facilitate the removal of the fault indicator module from connector 10 with a conventional lineman' 8 tool.
Operating power for the circuitry of fault S indicator module 20 i~ derived from conductor 11 by means of the metallic plate 2~, which when module 20 iB seated in te~t point ~ocket 18 i8 sufficiently clo~ely spaced to the conductor to provide a level of capacitive coupling whereby adequate alternating voltage i8 derived from the conductor for operation of the fault indicator circuitry. A necessary ground return for thi~ circuitry may be provided, as shcwn in Figures 1-5, by an electrical conductor 37 which extends through the ~idewall of hou~ing 22 and along the out~ide ~idewall of the housing~ When housing 22 i8 seated in test point socket 13 conductor 37 i8 brought into electrical communication with the electrically-conductive sidewall o~ -the socket, thus establishing the ground return through the electrically grounded sheath 13 of ~he connector.
By rea~on of the novel construction of test point soeket 18, connector 10 is manufactured without the use of a metallic contact member such as utili~ed in prior connector constructions. In~tead, the connector has on its exterior surface only the te~t point socket formed of electrically-conductiYe rubber sheath material. Since sheath 13 does not extend acros~ the bottom of the socket any aircuit condltion ~onitoring modul~ (~uah ~8 ~ault lndicator module ~0) ~eated in the socket 18 automatlcally coupled by means o~ lts ~ 3 internal metallic plate 25 to conductor 11. The surrounding electrically-conductive sheath material of the ~leeve portion 21 o~ the test point socket provides an efficient ground return path which ~ay conveniently e~tablished by either an exposed conductor, such as conductor 37 on the exterior of hou~ing 22, or by a second capacitive coupling element, as will be di~cribed in connection with ~igures 14 and 15.
In accordance with another aspect of the invention, the same circuit condition monitoring module 20 and protective end cap 30 utilized in conjunction with test point socket 18 can be utilized in conjunction with prior connectors using a metallic-contact type te~t point. To this end, the monitoring system of the invention utilizes, as shown in Figures 5-7, an adapter sleeve 40 which i~
dimen~ioned to fit over the inside end of housing 22 and extend between en.d cap 30, when installed on the housinq, and the metallic te~t point 41 of a prior connector 42. As be~t shown in Figure 7~ connector 42 includes a conventional metallic contact 43 which is exposed at test point 41 to provide capacitive coupling to a conduotor 44. Contact 43 forms an annular flange at test point 41. The adapter sleeve 40, which i8 formed of electrically-conductiYe rubber, include~ an electrically non-conductive lnterior ~5 ~leeve insert 45 which engage~ the annular ~lang~ of contact 43 ~o ~ain~Ain th~ adapter ln po~ition.
The ~dequate ~xcita~ion for the ~ault indicator module circuitry i8 obtained, in accordance with the invention, by capacitiYe coupling between metallic plate 25 and embedded con~act 43, and between the embedded contact and conductor 4~. The conductive body portion of sleeve 40 5 i8 in contact with the electrically conductive ~heath 46 of connector 42 to prvvide a ground return path for fault indicator module 20 in the manner previously described. The non-conductive interior sleeYe 45 preven~ contact 43 from ~eing grounded to the body of ~leeve 40. An a~nular rim portion 47 on 61eeve 40 engage~ the rim portion 31 of end cap 30 when module 20 i8 installed on the test point, as shown in Figures 6 and 7.
By reason of the u~e of other adapter sleeves other prior te6t point constructions can be accommodated ~y the circuit condition module of the invention. For example, in Figures 8 and 9 an alternate prior test point conatruction i8 shown wherein a connector 50 having a central conductor 51 has a generally washer-shaped metallic contact 52 embedded in a projecting test point portion 53 of the connector. In this in~tance, an alternate ~orm of sleeve-shaped adapter 53 engages a rim portion 54 molded into the connector hou~ing. No connection i 8 made between the adapter ~leeve 53 and contact 52. An annular rim portion on the sleeve a~sures a secure engagement ~ith connector 50 and the nece~sary ground retu~n path i8 e~tabll~hed th~ough the ~l~cttically conductive sheath SS o~
the connector. A~ be~ore, adequate AC exaitRtlon fo~ the ~ 3 fault indicator module circuitry i8 achievedin accordance with the invention, by capacitive coupling between the metallic plate 25 and the embedded contact 52, and between the embedded contact and conductor 51 of connector 50O
S With the Pxception of the provision of ~pecific for coupling to a monitored conductor and to ground, fault indicator module 20 may ~e conventional in con6truction and operation. In particular, to provide an indication of the occ~rrence of a fault current in conductor 11, the fault indica~or includes, as part of the previously identi~ied flag indicator a~sembly 27, a disc-shaped target 65 ~hich i~
mounted for rotation on a plvot 65. The ~ace of the target disc ha~ a red segment 65a ~Figures 10-12) and a white segment 65b, only one of which i~ visible at a time through window 33 and the transparent end 34 of housing 22.
Secured to and pivotal with target 65 is a targe~
permanent magnet 70, which i~ ~ormed o~ a magnetic material having a high coercive ~orce, such as ceramic, and i8 magnetically polarized to form two magnetic pole~ of opposite gender, as indicated in Figure~ 10-12, with opposite magnetic polaritieE along a diameter of the magnet.
The target di~c 65 and its permanent magnet 70 are biased to the position ~hown in Figures lOa and lOb when the fault indicator is in ~ non-tripped or reset condition ky mean~ of a stationary uw~haped mngnettc pole piece 71, whlch i~
prc~erabl~ ormed o~ a magnetlc mate~ial havlng a relatlvely low coercive forca, ~uch as a chrome ateel.
When ~he fault indicator i8 in a reset state, the projecting ends of the pole piece are bia~ed ~o the magnetic polarities indicated in Figures 10a and 10b. As a re~ult.
the opposite polarity magnetic pole~ of the target magnet 70 are attracted to position the target disc 65 as shown. In thi~ po~ition the red segment 65a of the target disc i~ not vi~ible through window 33, and all that is seen is the whi~e segment 65b.
On the occurrence of a fault current in conduc~or 11, which fault current may, for example~ exceed 400 amperes, pole piece 71 i8 remagnetized to the magnetic polarities shown in Figures 11 and 12 by momentary energization of a trip winding 72 on the center section of the pole piece. As a result, the poles of magnet 70 ~re repelled by the adjacent like gende~ pole~ ~f the pole piece and the target disc i8 caused to rotate 18Q to the tripped position shown in Figure~ 12a and 12b. In this position.
the red ~e~ment 65a o~ the target disc i8 visible through window 33, and a lineman viewing the ~ault indicator i8 advised that ~ fault current has flowed ~hrough conductor 11 .
The target dlsc remains in the fault indicating po~ition until the end~ of pole piece 71 are subsequently remagnetized to the magnetic polarities shown in Figures lDa ~5 and 10b ~y momentary energi2atlon o~ A reset windlng 73 on the ent~r ~ectiQn ~f ~he polc piece. A~ a ra~ult, the target ma~net 70, and hence the target di~c 65, ~re causea ~ 3 to rotate from the tripped position ~hown in Figure 12 to the re~et position sh~wn in Figure 10 and the fault indicator i8 conditioned ~o respond to a ~ub~equent fault current.
~nergization of winding 72 upon occurrence of a fault current in conductor 11, and energization of winding 73 upon restoration of current in conductor 11 following a fault, i8 accomplished by mean6 of circuitry contained within the fault indicator housing 22. Referring to the schema~ic diagram shown in Figure 13, windings 72 and 73 are connected end-to-end for independent energization upon occurrence of fault and re~et conditions, re~pectively.
Operating power for these windings is o~tained by means of a bridge rectifier network 80, con~iRting of diodes 81-84 .
One input terminal R thi~ network, formed at the juncture of the anode of diode 81 and the cathode o~ diode 82, i8 connected to the capacitive coupling pla~e 25. The othe~
input terminal, formed at the juncture of the anode of diode 83 and the cathode o~ diode 84, is coupled to ground through ~o the electrically conductive sheath 13 of connector 10, either by direct connection, as shown in Figures l-S, or by capacitive coupling, as shown in Figure 18. With this arrangement, high voltage alternatlng current carried in conductor 11 is c~pacitively coupled to the brldge recti~ier network, re~ulting in the productlon of a pulsatlng unidlrectional curr~nt ~t the output tarminal~ Q~ the neSwork.
The positive polarity output terminal of the bridge rectifier network, formed at the cathode~ of diodes 81 and 83, i~ connected to one contact of a reed switch 26, to the end termina~ 8 of winding~ 72 ~nd 73, and to 5 respective terminals of capacitors 87 and 88. m e negative polarity output terminal of the bridge rectifier network~
formed at the juncture of the anode of diodes 82 and 84, i8 connected directly to ~he remaining terminal of capacitor 87, and through a forward-biased diode 89 to the remaining terminal of capacitor 88. With this arrangement, capacitors 87 and B8 are charge~ by the pulsating unidirectional current developed by bridge rectifier network 80 in the presence o~ voltage on conductor 11.
To provide for periodic energization of reset winding 73 during normal current flow in conductor 11, the remaining end term~nal of winding ~3 i8 connected through a ~ilicon controlled rectifier (SCR) !~0 to the negative polarity terminal of capacitor 87. Periodic conduction through SCR 90 i8 obtained by connecting the gate electrode of that device to the positive polarity output terminal of bridge rectifler network 80 through a re6istor 91 and a bilateral diode 92, and to the cathode of SCR 90 by a resistor 93. With this arrangement, SCR 90 i8 periodically triggered into conduction when the voltage developed across bilateral diode 92 as a resul~ of capacitor 87 being charged by bridge reatifier B0 xeaches the threshold level of the bilateral diode.
~ 2 In operation, under normal current flow conditions, the vol tage developed acros~ capacitor 87 as the capacitor is charged by bridqe rectifier network 80 .progressively increases wi~h time, until the threshold ~reakdown voltage of bilateral diode 92 i~ reached, at whi~h time SCR 90 is triggered and capacitor 87 discharges through winding 73. Diode 89 prevents capacitor 88 from being di~charged through SCR 90 and winding 73, leaving the capacitor available for energizing winding 72 in response to a fault condition. In practice, the breakdown voltage of bilateral diode 92 may be in the order of 34 volts, and the time required for capacitor 88 to reach thi~ threshold level with a voltage level of 4,4~0 Yolts on conductor 11 may be approximately 2 minutes. In any case, the voltage level within conductor 11 is not critical to the operation o~ the reset circuit, and ha6 only the ~ffect of changing the frequency of the re~et ~yc}e.
Trip winding 72 i~ energized upon occurrence of a fault current in conductor 11 by discharge of capacitor 88 through a ~econd silicon controlled rectifier 100.
Conduction i8 established through SCR 100 by closure of the contacts of reed switch 26, which i~ positioned within housing 22 so as to be in proximity to conductor 11 when tbe module i8 seated in te~t socket 18. The gate electrode o~
SCR 100 ls connected through a bilateral diode 101 and re~i~tor 102 to the cQnt~ct~ of ~eed swltch B6, and by ~
~esistor 103 to the SCR cathode. ~he ~uncture o~ re~istor ~_f2~1.2 J_~3 and bilateral diode 104 i8 connected by a capacitor 104 to capacitor 88.
Upon occurrence of a fault current in conductor 11, the positive polarity output terminal of bridge rectifier network 80 i5 connected thro~gh the then closed contacts of reed fiwitch 26 and the circuit comp~i~ing resi~tor 102, bilateral diode 101, re~istor 103, and capacitor 104 to the gate electrode of SCR 100, cau~ing that device to be rendered conductive following a predetermined time delay. At this time ~apacitor~ 87 and 88 are caused to discharge through SCR 10~ and energize winding 82. The resulting magnetic f1UY in the ~-shaped pole piece 71 reverses the magnetic pole polaritie~ of the pole piece and causes rotation of the taryet as previously de~cribed.
To avoid the possibility of rotor 85 becoming stalled upon reversal of the ~agnetic polarities o~ pole piece 71, as might happen with a rotor being perfectly centered between the poles of pole pieces 71 and having a degree of bearing f riction, the ~ault indicator includes an auxiliary U-shaped pole piece llQ positioned adjacent target means 70 coaxial with and at an angle to pole piece 71.
The existence of a magnetic field betwePn the poles of pole piece 71 results ln the productlon of induced magnetic pole~ on auxiliary pole piece 110 of opposite gender to the mo~t adjacent pole~ of pole ple~e 71~ Thi~ i8 illustrated ln Fi~ure~ 10-1~ and ra~ult~ ~y rea~on of the auxlliary pole piec~ llC beco~ing included in he magnetlc l2~3 flux path between the poles of pole piece 71. The effect of the induced magnetic pole6 ic that upon rever~al of the gender of the poles of pole piece 80 following occurrence of a fault current the auxiliary poles exert a rotational force on the most adjacent poles of the permanent rotor magnet 70 as~ociated with target 65. Thi~ results in a rotational moment being exerted on the target, tending to turn the target in a predetermined ~counter-clockwise in Figure~
10-12) direction such that the target i8 pre~luded fr~m remaining in its reset po~ition, even if it should be perfectly positioned and have a degree of bearing friction.
Once rotation has been establi6hed, as shown in Figure 11, the greater force of the main pole piece 71 overcomes the effect of the auxiliary pole piece 110 and rotation continues until the target i8 aligned as shown in Figure 12.
Other fault indicator circuit~ having different or additional operating features, such a~ the fault indicator circui-ts described in the U.S. Patents Nos. 4,795,982 and 4,686,518 may be utilized in place of the circuit shown by replacing the prior spring contact metallic coupling element with a capacitive coupling element, and adapting the ground return means in accordance with the intended use.
In an alternative embodiment o~ the in~ention '~ ~.2 ~
~hown in Figures 14 and 15 the external wire 37 utilized to establi~h electrical communication with the ~idewall of test point 60cket 18 i8 replaced by a second capacitive coupling element in the form of a bras~ ring or cylinder 106 on the S inside surface of housing 22. Thi8 ring capacitively couples the fault indicator circuitry through the hou~in~
wall to the electrically conductive socket sidewall 21 and the overlying cap member 30, which are connected to yround through sheath layer 13. Thu~, the requisite ground return path i~ establi~hed without an external contact on the housing. Since the coupling to conductor 11 is also obtained in accordance with the invention, without an ex~ernal contact the fault indicator module is desirably entirely free of exposed contacts.
While a ring-shaped coupling element 106 has been shown, it will be appreciated that other construction~ for thi~ element are possible, including a single plate positioned against the inside surface of the module housing opposite ~idewall 21.
As shown in Figure 15, should an electrically conductive surf ace be desi red on the bottom wall 107 of test point ~ocket 18 for any reason, it would ba possi~le to deposit or otheewise apply a thin resistive coating lOB
formed of a conductlve paint or rubber on the bottom wall 107 providad ~uch coating does not contact the electrically conductive ~idew~ 21 o~ the socket.
In certain appllcatlon~, such as where te~t z~
equipment i8 to be temporarily coupled to a monitored conductor, a contact a~sembly 110 can be temorarily in~erted in test point 30cket la to provide a metallic test point ~o which the in~trumentation can be connected. In particular, as shown in Figure 16, the contact assembly may include a body 111 formed of electrically non-conductive rubber dimensioned to fit within the ~ocket. A metallic capacitiYe coupling element in the form of a plate 112 is positioned within the body 80 as to couple to conductor 11, while avoiding contact with the electrically conductive sidewalls of the socket. A combination electrical terminal and hook member 113 extends axially within housing 111 from plate 112 ~o a location external to the housing, where it can be connected to or used to install or remove the contact 1~ as~embly.
When the te~t paint socket i8 not in u~e it may be desirable to install a plug member in the socket. This not only prevents the collection of dirt in the socket, but al~o eliminates any perception of a shock haza~d from the exposed bottom wall of ~he hou~ing. As shown in Figure 17, the plug member, generally designated 120, may comprise an electrically conductive rubber body 121 have a rim portion formed therein Por engaging the rim portion 3~ of test point socket 18, and a projecting handle portion 1~3 having an aperture 124 ~or enga~ement ~ith the hook end of a conventional llneman'~ tool~
In a further modificatlon of the invention sho~n ~ 3 in Figure 18, the coupling between the fault indicator circuit and monitored conductor 11 i8 increa~ed by formin~
test point socket 18 partially in the body portion of the connector. Consequently, when the fault indicator is seated in the body portion 125 of the socket, against the recessed bottom surface 126, the capacitive couling plate 25 of the module i8 positioned clo~er to conductor 11. A11 other construction feature~ of the invention may remain unchanged, and the alternate constructions of Figure~ 14 and lS, the test adapter of ~igure 16 and the elec~rically conductive cap member 121 remain applicable.
The components of the circuit condition monitoring ~ystem of the invention may be manufactured using conventional technique and material~. In particular, connector 10 may have an insulating layer formed of EPDM
material and conductive sheath formecl of the same material impregnated with carbon. The module housing may be ~ormed of Lexan (Trademark o~ General Electric Compan~) or an acrylic, and the end cap and adapter may be formed of a carbon-impregnated EPDM rubber.
Thu8, a ~ystem ha~ been ~hown which incorporate6 a novel teRt point socket in a connector by which various circuit condition monitoring modules can be brought into elect~ical communication with a monitored conductor without the need ~or provlding expo~ed electrical contacts ~or ~ecuring capacitiv& coupllng tQ the conductor. Moreover, novel cons~ruction for the circuit condition monitoring ~t~ 3 module ha~ been shown which enables the module, when used in coniunction with appropriate adapter sleeves, to be installed on either a test point socket constructed in accordance with the invention, or on a prior te~t point construction of the type having an exposed metallic contact.
No change~ are required in the module and the need for exposed contact~ on the module is obviated in favor of internal capacitive coupling means.
While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that change~ and modifications may be made therein without departing from the invention in its broader aspects, and, therefore, the aim in ~he appended claims is to cover all such changes and modification~ as fall within the true spirit and ~cope of the invention.
Claims (37)
1. A connector for establishing an electrical connection between the electrical terminals of components of an electrical distribution system, said connection being monitored by a removable circuit condition monitoring module requiring simultaneous electrical coupling to said electrical connection and to electrical ground, said connector comprising:
a connector body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the electrical terminals of said components;
electrical conductor means extending within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being substantially surrounded by said body portion:
an electrically grounded sheath layer formed of an electrically-conductive material overlying the surface of said body portion; and means defining on the surface of said connector a recess forming a test point socket for receiving the circuit condition monitoring module, at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said body portion said test point socket further being complementarily dimensioned to the circuit condition monitoring module whereby the monitoring module, when received in said socket, is fixedly positioned and simultaneously electrically coupled through said non-conductive body portion to said monitored conductor means and through said sheath layer to electrical ground.
a connector body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the electrical terminals of said components;
electrical conductor means extending within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being substantially surrounded by said body portion:
an electrically grounded sheath layer formed of an electrically-conductive material overlying the surface of said body portion; and means defining on the surface of said connector a recess forming a test point socket for receiving the circuit condition monitoring module, at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said body portion said test point socket further being complementarily dimensioned to the circuit condition monitoring module whereby the monitoring module, when received in said socket, is fixedly positioned and simultaneously electrically coupled through said non-conductive body portion to said monitored conductor means and through said sheath layer to electrical ground.
2. A connector as defined in claim 1 wherein the circuit condition monitoring module and said test point socket are generally cylindrical in form and aligned generally radially relative to said conductor means.
3. A connector as defined in claim 1 wherein at least a portion of said test point socket is formed of said electrically conductive material and the circuit condition monitoring module is coupled through said conductive portion to ground.
4. A connector as defined in claim 3 wherein said conductive portion comprises at least a portion of the sidewall of said test point socket.
5. A connector as defined in claim 3 wherein the circuit condition monitoring module includes a capacitive coupling electrode for establishing electrical coupling to electrical ground, and said electrically conductive portion of said test point socket is capacitively coupled thereto when the module is seated in said test point socket.
6. A connector as defined in claim 5 wherein said electrically conductive portion of said test point socket comprises a portion of the sidewall of said socket.
7. A connector as defined in claim 5 wherein the bottom of said test point socket is flat and formed substantially of said non-conductive material of said body portion, and the monitoring module has a complementary flat end surface.
8. A connector as defined in claim 1 wherein said test point socket includes around the open end thereof a rim portion formed at least partially of said electrically conductive material of said sheath layer, said rim portion being dimensioned to mechanically engage the circuit condition monitoring module when seated in the test point socket whereby an ohmic connection is established between said module and ground.
9. A connector as defined in claim 8 wherein the circuit condition monitoring module includes an electrically conductive housing, and said rim portion is dimensioned to mechanically and electrically engage said housing.
10. A connector as defined in claim 8 including a removable plug member formed of an electrically conductive material dimensioned when seated in said test point socket to extend from the bottom of said socket to the open end thereof in mechanical and electrical engagement with said sheath layer whereby the electric field of said conductor means is contained within the connector.
11. A connector as defined in claim 1 wherein at least a portion of the exterior surface of the circuit condition monitoring module received in said test point socket is electrically conductive and in ohmic contact with said sheath layer when the module is seated in said socket.
12. A connector as defined in claim 11 wherein at least a portion of the sidewall of said test point socket is formed by said sheath layer, and said conductive portion of said exterior surface of said module is in ohmic electrical communication therewith.
13. A connector for an electrical power distribution system for establishing an electrical connection between terminals of components of the system said connection being monitored by a removable circuit condition monitoring module requiring capacitive coupling at one end thereof to said electrical connection and ohmic electrical connection between an electrically conductive portion along the side thereof and electrical ground, said connector comprising:
a connector body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending within said connector body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being surrounded by said body;
an electrically grounded sheath layer formed of electrically-conductive material overlying said body;
means defining on the surface of said connector a recess defining a test point socket extending from said surface in a generally radial direction relative to said conductor means for receiving the circuit condition monitoring module; and at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said connector body portion, said test point socket further being complementarily dimensioned to the circuit condition monitoring module whereby said module when received within said test point socket is fixedly positioned relative to said body portion, capacitively coupled to said conductor means and ohmically connected to said sheath layer.
a connector body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending within said connector body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being surrounded by said body;
an electrically grounded sheath layer formed of electrically-conductive material overlying said body;
means defining on the surface of said connector a recess defining a test point socket extending from said surface in a generally radial direction relative to said conductor means for receiving the circuit condition monitoring module; and at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said connector body portion, said test point socket further being complementarily dimensioned to the circuit condition monitoring module whereby said module when received within said test point socket is fixedly positioned relative to said body portion, capacitively coupled to said conductor means and ohmically connected to said sheath layer.
14. A connector as defined in claim 13 wherein said test point socket includes around the open end thereof a rim portion formed at least partially of said electrically conductive material of said sheath layer, said rim portion being dimensioned to mechanically engage the circuit condition monitoring module when seated in the test point socket.
15. A connector as defined in claim 14 wherein the circuit condition monitoring module includes an electrically conductive housing, and said rim portion is dimensioned to mechanically and electrically engage said housing.
16. A circuit condition monitoring system for an electrical power distribution system providing a monitored connection between the terminals of electrical components within the distribution system, said system comprising:
a connector including a body portion formed of electrically non-conductive material:
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being substantially surrounded by said body portion;
said connector further including an electrically grounded sheath layer formed of an electrically-conductive material overlying the surface of said body portion;
a circuit condition monitoring module including a monitoring circuit operable from a capacitive coupling to said conductor means and an electrical coupling to electrical ground; and means defining on the surface of said connector a recess forming a test point socket for receiving said circuit condition monitoring module, at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said connector body portion, said test point socket being complementarily dimensioned to said circuit condition monitoring module whereby said monitoring module when received within said test point socket is fixedly positioned and simultaneously capacitively coupled to said monitored conductor and electrically coupled to electrical ground.
a connector including a body portion formed of electrically non-conductive material:
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being substantially surrounded by said body portion;
said connector further including an electrically grounded sheath layer formed of an electrically-conductive material overlying the surface of said body portion;
a circuit condition monitoring module including a monitoring circuit operable from a capacitive coupling to said conductor means and an electrical coupling to electrical ground; and means defining on the surface of said connector a recess forming a test point socket for receiving said circuit condition monitoring module, at least a portion of the bottom of said test point socket being formed of said electrically non-conductive material of said connector body portion, said test point socket being complementarily dimensioned to said circuit condition monitoring module whereby said monitoring module when received within said test point socket is fixedly positioned and simultaneously capacitively coupled to said monitored conductor and electrically coupled to electrical ground.
17. A monitoring system as defined in claim 16 wherein said circuit condition monitoring module includes an internal capacitive coupling element at one end for establishing said capacitive coupling to said conductor when said module is seated in said test point socket, and ground return means for establishing electrical coupling between said monitoring module and ground, said test point socket is dimensioned to receive said monitoring module with said one end thereof extending toward said conductor means and said ground return means being operable through said sheath layer, whereby in the presence of an alternating current voltage on said conductor a voltage is induced within said module.
18. A monitoring system as defined in claim 16 wherein the circuit condition monitoring module and said test point socket are generally cylindrical in form and aligned generally radially relative to said conductor means.
19. A monitoring system as defined in claim 16 wherein at least a portion of said test point socket is formed of said electrically conductive material and the circuit condition monitoring module is coupled through said conductive portion to ground.
20. A monitoring system as defined in claim 19 wherein said conductive portion comprises at least a portion of the sidewall of said test point socket.
21. A monitoring system as defined in claim 19 wherein the circuit condition monitoring module includes a capacitive coupling electrode for establishing electrical coupling to electrical ground, and said electrically conductive portion of said test point socket is capacitively coupled thereto when the module is seated in said test point socket.
22. A monitoring system as defined in claim 21 wherein said electrically conductive portion of said test point socket comprises a portion of the sidewall of said socket.
23. A monitoring system as defined in claim 22 wherein said capacitive coupling electrode comprises a metallic ring within said module.
24. A monitoring system as defined in claim 19 wherein said test point socket includes around the open end thereof a rim portion formed at least partially of said electrically conductive material of said sheath layer, said rim portion being dimensioned to mechanically engage the circuit condition monitoring module when seated in the test point socket whereby an ohmic connection is established between said module and ground.
25. A monitoring system as defined in claim 24 wherein the circuit condition indicating module includes an electrically conductive housing, and said rim portion is dimensioned to mechanically and electrically engage said housing.
26. A monitoring system as defined in claim 24 including a removable plug member formed of an electrically conductive material dimensioned when seated in said test point socket to extend from the bottom of said socket to the open end thereof in mechanical and electrical engagement with said sheath layer whereby the electric field of said conductor means is contained within the connector.
27. A monitoring system as defined in claim 16 wherein at least a portion of the exterior surface of the circuit condition monitoring module received in said test point socket is electrically conductive and in ohmic contact with said sheath layer when the module is seated in said socket.
28. A connector as defined in claim 27 wherein at least a portion of the sidewall of said test point socket is formed by said sheath layer, and said conductive portion of said exterior surface of said module is in ohmic electrical communication therewith.
29. A monitoring system as defined in claim 16 wherein the bottom of said test point socket is flat and formed substantially of said non-conductive material of said body portion, and the monitoring module has a complementary flat end surface.
30. A monitoring system providing a monitored connection between the terminals of electrical components within an electrical power distribution system, said system comprising:
a connector including a body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending generally axially within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being surrounded by said body portion;
said connector further including an electrically grounded sheath layer formed of electrically-conductive material overlying said body portion;
a circuit condition monitoring module operable from a capacitive coupling to said conductor means, and an ohmic electrical connection to ground; and means defining on the surface of said connector a recess forming a test point socket aligned in a generally radial direction relative to said conductor means for receiving said circuit condition monitoring module, at least a portion of the bottom of said recess being formed of said electrically non-conductive material of said connector body portion, said test point socket further being complementarily dimensioned to said circuit condition monitoring module whereby said monitoring module when received within said test point socket is fixedly positioned relative to said body portion, capacitively coupled to said conductor means and ohmically coupled to said sheath layer.
a connector including a body portion formed of electrically non-conductive material;
first and second terminal means for electrically and mechanically engaging the component terminals;
electrical conductor means extending generally axially within said body portion between said first and second terminal means for providing an electrical current path therebetween, said conductor means being surrounded by said body portion;
said connector further including an electrically grounded sheath layer formed of electrically-conductive material overlying said body portion;
a circuit condition monitoring module operable from a capacitive coupling to said conductor means, and an ohmic electrical connection to ground; and means defining on the surface of said connector a recess forming a test point socket aligned in a generally radial direction relative to said conductor means for receiving said circuit condition monitoring module, at least a portion of the bottom of said recess being formed of said electrically non-conductive material of said connector body portion, said test point socket further being complementarily dimensioned to said circuit condition monitoring module whereby said monitoring module when received within said test point socket is fixedly positioned relative to said body portion, capacitively coupled to said conductor means and ohmically coupled to said sheath layer.
31. A monitoring system as defined in claim 30 wherein said test point socket includes around the open end thereof a rim portion formed at least partially of said electrically conductive material of said sheath layer, said rim portion being dimensioned to mechanically engage the circuit condition monitoring module when seated in the test point socket.
32. A monitoring system as defined in claim 31 wherein the circuit condition monitoring module includes an electrically conductive housing, and said rim portion is dimensioned to mechanically and electrically engage said housing.
33. A circuit condition monitoring module for installation on a connector having an electric conductor, a non-conductive body portion over the conductor, an electrically conductive sheath layer overlying the body portion and a test point socket formed in the sheath layer, the test point socket having a bottom end within the electric field of the conductor and being formed at least in part of the electrically non-conductive material forming the connector body portion, said module comprising:
a circuit condition monitoring circuit operable from an applied alternating voltage;
a housing for containing said circuit, said housing being dimensioned to fit within said test point socket with an interior end thereof adjacent the bottom end of the socket;
first electrical coupling means comprising a capacitive coupling element within said housing at said interior end thereof for electrically coupling said monitoring circuit to the monitored conductor; and second electrical coupling means for electrically coupling said monitoring circuit to the sheath layer whereby said monitoring circuit is powered by alternating current on the monitored conductor when seated in the test point socket.
a circuit condition monitoring circuit operable from an applied alternating voltage;
a housing for containing said circuit, said housing being dimensioned to fit within said test point socket with an interior end thereof adjacent the bottom end of the socket;
first electrical coupling means comprising a capacitive coupling element within said housing at said interior end thereof for electrically coupling said monitoring circuit to the monitored conductor; and second electrical coupling means for electrically coupling said monitoring circuit to the sheath layer whereby said monitoring circuit is powered by alternating current on the monitored conductor when seated in the test point socket.
34. A circuit condition monitoring module as defined in claim 33 wherein said capacitive coupling element comprises a metallic plate positioned at the interior end of said housing.
35. A circuit condition monitoring module as defined in claim 33 wherein at least a portion of the sidewall of said housing is electrically conductive, and said second electrical coupling means comprise a capacitive coupling element for coupling said circuit to said electrically conductive portion of said sidewall of the test point socket.
36. A circuit condition monitoring module as defined in claim 33 wherein said second electrical coupling means comprise an ohmic electrical connection between said monitoring circuit and said electrically conductive portion of said sidewall of the test point socket.
37. A circuit condition monitoring module for installation on a connector having an electric conductor, a non-conductive body portion overlying the conductor, an electrically conductive sheath layer overlying the body portion, and a test point socket formed in the sheath layer, the socket having a bottom end within the electric field of the conductor and being formed at least in part of the electrically non-conductive material forming the connector housing, said module comprising:
a circuit condition monitoring circuit operable from an applied alternating voltage;
a housing formed of electrically non-conductive material for containing said circuit, said housing being dimensioned to fit within said test point socket with the interior end of said housing adjacent said bottom end of the test point socket;
a first capacitive coupling plate within said housing adjacent said interior end thereof for electrically coupling said monitoring circuit to the monitored conductor; and ground return coupling means comprising a capacitive coupling ring around the inside surface of said housing at an axially-spaced location relative to said capacitive coupling plate for coupling said monitoring circuit to the electrically conductive sheath layer of said connector when the module is seated in said test point socket whereby said circuit is powered by alternating current on the monitored conductor.
a circuit condition monitoring circuit operable from an applied alternating voltage;
a housing formed of electrically non-conductive material for containing said circuit, said housing being dimensioned to fit within said test point socket with the interior end of said housing adjacent said bottom end of the test point socket;
a first capacitive coupling plate within said housing adjacent said interior end thereof for electrically coupling said monitoring circuit to the monitored conductor; and ground return coupling means comprising a capacitive coupling ring around the inside surface of said housing at an axially-spaced location relative to said capacitive coupling plate for coupling said monitoring circuit to the electrically conductive sheath layer of said connector when the module is seated in said test point socket whereby said circuit is powered by alternating current on the monitored conductor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US062,875 | 1979-08-01 | ||
| US6287587A | 1987-06-16 | 1987-06-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1291213C true CA1291213C (en) | 1991-10-22 |
Family
ID=22045419
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000561664A Expired - Lifetime CA1291213C (en) | 1987-06-16 | 1988-03-16 | Circuit condition monitoring system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1291213C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113078961A (en) * | 2021-03-12 | 2021-07-06 | 维沃移动通信有限公司 | Detection method and detection device for electronic equipment test state |
-
1988
- 1988-03-16 CA CA000561664A patent/CA1291213C/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113078961A (en) * | 2021-03-12 | 2021-07-06 | 维沃移动通信有限公司 | Detection method and detection device for electronic equipment test state |
| CN113078961B (en) * | 2021-03-12 | 2022-08-02 | 维沃移动通信有限公司 | Detection method and detection device for electronic equipment test state |
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