US1765500A - Automatic sectionalizing switch - Google Patents

Description

June 24, 1930. M. E. REAGAN 1,765,500

AUTOMATIC SECTIONALIZING SWITCH Filed Sept. 16, 1921 INVENTOR 7 ATTORNEY V Patented June 24, 1930 fnniriinsrara sarsnr car es .IMAURICE E. REAGA'N Q OF PITTSBURGH, PENNfsYLVANIA, ASSIGNOR TO WESTINGHOUSE [ELECTRIC & MAIlUFACTUR-ING: COMPANY, A COEPGRATION OF FEENIQ'SYLVANIA AUTOMATIC SECTIONALIZING SW'ITCI-I Application filed September 18, 1921. Serial No. 501,156.

ing circuit interrupters and particularly to devices generally known as sectionalizing switches;

One object of my inventionis to provide a circuit interrupter for connecting circuits or sections of a circuit that will open upon the occurrence of a predetermined overload r voltage so long as the overload'or short-circuit condi- .tion in either section, or the low voltage on the system, remains, but which will close when the overload or short-circuit condition I is removed and the potential conditions of both circuits or sections again becomes substantially normal. 7

Another object ofmy invention is to provide a structure of the aboveunchc'ated character whereinthe'reclosing of the sectionalizing switch is controlled in accordance with the value of the resistance connected to, and included 1n,one oi the seetlons.

A further object of my invention is to pro-' vide means whereby, upon the opening of the sectionalizing switch by reason or the occurrence of a short-circuit, the resistance of .thetaultysection may be measured and the reclosing of the sectional'izing switchcontrolled in accordance with the value of such resistance; o Another objectot my invention is to provide a system of the above-indicated character, that shall be operative whether both sections or circuits are being independently supplied with energy or whether only one section is sosupplied.

f Astill further object of my invention is to provide asystem, of the above-indicated character, wherein standard apparatus or" a rugged character may be employed that shall be relatively simple and inexpensive in its construction, and rel able and-eitectlve in its operation.

(lo-pending application Serial No. 375,- 965, filed April 23, 1920, byJ. H. Procter, and assigned to the Westinghouse Electric & Manufacturing Company, which has since matured into UnitedflStates Patent No. 1,632,988, discloses an automatically reclosing circuit interrupter, the reclosing of which is controlled by a \Vheatstone bridge when the load that is connected to the circuit controlled by the interrupter attains a predetermined value.

In practicing my invention, I employ the 'ciple disclosed in the aforementioned application and apply it to the control of a sectionalizing' switch, I so arrange aplurality or resistors and control relays that, upon the opening of thesectionalizing switch because oi abnormal conditions in either section, the resistors are connected to the faulty section to compose a Wheatstone bridge, one arm of which comprises the resistance of the conductors of one section and of the load connected thereto. /Vhen the resistance of the load that is connected to the faulty section attains a predetermined value, indicating the passage oi abnormal conditions, the sectionalizing switch is reclosed.

Figure 1 of the accompanying drawings is a simplified diagrammatic view of a sectionalizing switch and the control apparatus associated therewith.

2 is a modification of 1, and illustrates the arrangement of additional resistors for the relay switches, and

Fig. 3 is a simplified diagrammatic view illustrating schematically the arrangement of the various resistors under predetermined conditions in the system illust'ated in Figs. 1 and 2. i

In Fig. 1 are illustrated two circuits or sections 1 and 2, re pectively, that are adapted to be connected by a circuit interrupter 3. The interrupter 3 comprises a plurality of contact members 4: and 5, the engagement of which is affected and maintained by an opertermined value, after the interrupter 3 has been opened by reason of the occurrence of an overload or short-circuit upon either of sec tions land 2.

' mined The operating coils of two rela devices 10 and 11 are respectively connected tween the section conductors 1 and 2 and a return conductor I2'through a resistor 13 of relatively low resistance.

The relay device 10 is provided with three switches 14, 15 and 16 that are closed when the rela device is energized to a predeteregree and that are open when the coil of the relay device is energized less than a predetermined degree. 1

Therelay device 11 is similarly provided with switches 17, 18 and 19 that are similarly maintained in closed or in open position, according to Whether the o erati coil'of the relay is energized to a su cient egree or not.

One contact memberof the switch 14' and one contact member of the switch 15 'areponnectedto the section conductor 1, and,ls'imio'flthe switch-1T the switch 7, toithh conductor 2Q,by means of 'lafrly, one contact member o f the h 17 and one contact member of the-switch 8 are "connected to thefgection conductor 2. The

other contact"memb ers ofthe switchil l and "%1e ,conn ected bya conductor similarlyffle other contact members of .he switch 15 anflof the switch 18 are confijcted by acbtl l kitor 21*. ,1. p Q ",The switch 16 ia'coml'ecteiiinseries with" conductors 22v and 23. The 'correspondin switch 19 of 'thirelay device 11,1when close serves to connect one terminalof the operating coil 6, of the sectionalizing switch 3, to the return conductor 12. -j i "Upon theclosure of either the switch 15 or the switch 18, a resistor24, havinga resistance of relativelylargevalue, isconnected in series with the resistor 13fbetween' the section 1 and'retln n eonductor 12 or between the section 2 andthe return conductor 12. 1

"Assuming the occurrence of a short circuit between the sectien'fconductor 2 and the conductor 1 2, currentwill tend to flow through the circuit from the section conductor 1, through the relay 8 and the sectionalizing switch 3, to the section'2. when the value of such current exceeds a predetermined value at which the overload relay 8 is set to operate, the switch 7 will open. The 0 eratingcoilfi is thereupon deenergized and t e sectmnalizing switch 3 is opened. The switch '3 being open, current from the section conductor 1 may be Supplied to the short-circuit onthe section 2 through the resistor 9 that has a relatively large value of resistance. [Since the section 1 is normal, the voltage of that section will be sufficient to maintain the operating coil of the relay device 10 energized to maintain the switches 14, 15 and 16 closed. The relay device'll, however, is not suflicientvalue, the switchf3 will be 1y energizedto maintain its switches 17, 18 and 19 closed. J

By reference to'the diagram in 3, it will be seen that the resistors 24, 13 an 9 constitute three arms of a Wheatstone bridge of. which the section conductor 2, the short circuit therein and the load connected thereto constitute the fourth arm. The 0 crating coil' of the relay device 11 corresponds to the galvanometer that is connected between equi-potential points of a Wheatstone bridge.

FIG

When the resistance of the circuit, includingthesectionconductor 2, the load connected thereto and the short-circuit therein, in-

creases to 'a predetermined value, the operating coil of t e relay device 1,1 will elfect'the closure'o'f its switches. 17, 18' and 19. The

circuit of the operating coi'l 6 will there In be completed and the sectionalizin switch will be reclosed. It will be observed t at both relay devioesIO and 11 must the energization of the operating coil 6.

' By arranging the values of the resistance of the resistors 9, 13 and 24 to bear certain re- 11 may be cause lations with respect tdeach other,the relay. to operat'efor any predetrf be closed to efleet mined value of resistance that may be nected to the section 2; various resistors that. the relay 1 closed only when the, resistance connecte to. the circuit section 2 exceeds a predetermined precluded-frem'ref soarra' 'n the By i ivifitae closing until the shortroircuit conditions are v 7 clear and the load connected to the section exceeds a predetermined value. Although the relay 11 is'illustrated as of the circuit-closing type, it'is obvious that the resistors may be so arranged as to permitthe employment o'fa I circuit-opening or drop-out switch which will be tie-energized when the resistors. are balanced. v I

If the short-circuit conditions occur upon the section .1, the relay 11' will remain energized to maintain its switches 17, 18 and'l9 closed, and the switches 14, 15 and 16 will remain open. The section cofiductorI-and the load connected thereto will then constitute the fourth arm of the Wheatstone bri'dge (39m! posed of the resistors 9, 13 and 24, andfthe relay device 10 will constitute the controlling element.

By means of such anarrangement, com prising a Wheatstone bridge, it will be observed that-a veryaccurate measurement of the load resistance may be effected, and the operation of the control relay. devices 10 and 11 may be rendered correspondingly sensitive.

In the arrangement illustrated in 2,

the various elements that are employed are similar in character to those illustrated in Fig. A

1, and the operating coils of the relay devices 10 and 11 are provided with limiting resis-- tors 26 and 27. The function of the resistors 26 and 27 is to limit the value of current that i [may traverse the coilslO and 11 when the entire-system is operative,'in order toreduce the heating and the losseswithin those coils. The resistors 26 and 27 are connected in series with the, coils l and 11 and thecorresponding section conductors l and .2. y I

The value oi the resi"tors 2G and 2'? is so calibrated that suflicient current will be permitted to traverse the Cells and 11 to maintain the switches in closed position only after the actuation of the switches to such positions. The value of current that may traverse the coils while the resistors are eiiecti'vely inserted in circuit therewith is insufficient to eiiect the actuation of the relay devices to close the switches.

In order to permit the operating coils of the relays 10 and 11 to be suiiiciently energized to close the corresponding switches, the resistor 26 lS'SllOIh-ClfClllbGd. by two switches 28 and] 29, and the resistor 27 is similarly short-circuited by two switches and 31. The switches 28 and 30 are closed when the sectionalizing switch 3 is open and are open when the sectionalizing switch 3 is closed.

The switches 29 and-31, similarly, are closed when the relay devices'lO and 11 are in their'de-energized, or open, positions, and the switches are opened when the relays l0 and 11 are in their energized, or closed, positions. I

Thus, when the sections 1 and 2 are supplied with energy at normal voltage, sufficient current traverses the operating coils of the relays'lO and 11 to efiect the closing of the associated switches. The switches 29 and 31 are arranged to open when the movable members of the associated relay devices are almost at the end of their travel. At that position,

7 the value of current that is permitted to traverse the coils 10 or 11 is suificient to maintain the switches closed.

Two resistors 32 and 33 are provided in circuit with the switches 15 and 18 of the relays 10 and 11 to preclude an eXcessive currentfrom traversing those switches when they are closed by the cnergization or the associated relays before the closure of the main switch 5 isei'lected.

By employing a measuring system such as that illustrated and described, the reclosing of the sectionalizing switch may be accurately controlled in accordance with a predetermined value. of resistance in the sections that are connected by the switch.

My invention is not limited to apparatus of the specific type illustrated or to the particular .arrangementof such apparatus since various modifications may be made therein within the spirit and scope of the invention, as

set forth in the appended claims.

I claim as my invention l. In an automatically-reclosing sectionalizing circuit-controlling system, means for connecting two circuit sections, means, in-

eluding a Wheatstone bridge, forcontrolling the connecting means, and means for connectergized from one of the sections, a resistancemeasuring means for controlling the connecting means, and means responsive to the conditions of both circuit sections for automatically connecting the resistance-measuring means selectively to either section.

4. A control system for a sectionalizing switch between two section conductors including a plurality of resistors arranged to constitute a Wheatstone bridge, one arm of which includes one section conductor and the load connected thereto,- and means for connecting the b idge selectively to either section conductor.

5. An automatically-reclosing sectionalizing circuit-controlling system having means for connecting two circuit sections and means whereby one section conductor and the load connected thereto are connected to a network of resistors to constitute a Nheatstone bridge, means responsive to a predetermined balance therein for controlling the connecting means, and means iorestablishing the VVheatstone bridgeby connecting the resistors selectively to either circuit section.

6. An automatically-reclosing sectionalizing circuit-controlling system having means for connecting two circuit sections and meansresponsive to the conditions of both circuit sections whereby either section conductor and the load connected thereto are selectively connected in circuit with a resistance-responsive means, and means controlled by the resistance-responsive means for controlling the connecting means. I

7. The combination with two adjacent section conductors of a distributing system and a main contact member for connecting the conductors when in closed position, of a limit ing resistor connected between the sections to limit the exchange of current therebetween when the main contact member is open, two auxiliary resistors, a relay switch energized from each section conductor and responsive to the potentials thereof, one of the relay switches operating to connect the auxiliary resistors to the associated section conductor to complete. a Wheatstone bridge arrangement and the other relay switch operating as the parison resistor 'of predetermined ppotential-irespo nsiveelement of. the bridge thus constituted by the resistors and the other section conductor and connected load.

8. An automatically-reclosing sectionalizing circuit-controlling system including .means forconnecting two circuit sections,

means, comprising a. resistance-responsive deand means ;for automatically applying the. re

1 sistance-responsive device selectively to either section.

10. An automatically-reclosing sectionalizpendent upon one section and=the doadicon nected thereto attaining a predeterm'inqd value of resistance, of the other section;

scribed my 1921. g

MAURICE LREAGANw 1 vice, for-controlling said connecting means 7 I circuit-controlling system having means for connecting two circuit sections, means in- 7 clndin a resistance-comparin device ,for cnntro lincg the operation of em connecting meansan means responsive to the electrical din s; ofrhoth circuit ,rmeansfor automatica y cu tsections, means for controlling said connccting means haying a I .the connecting means,

condition ofboth circuit sections for controlling the applicationofthe resistance-comparing device selectively to either circuit sec- 1 tron.

, 11. Anaut matically-reclosing sectionaliz- A ing circuit-eontrollin' system including connecting two cirpotential-balsnce arent and means responsive tothe con- 7 sectlonsforcontrolling the-application of the "balance arrangement selectively tpcither section. V '12. 'An automatically-reclosing sectionaliz- .circuitcontrollin 7 system including means .for automatica y connectingtwo cir- .;;int sections, operating means therefor,

means energized from both ctions and arranged to constitute a resistance'measuring chance, when the sections to control the energizatiqn ofthe operating means, and means for applying the resistance-measuring device selectively to either circuit section. 1a. cThecomhinationn all two fldlfl flntcircpit sections normally in ividually energized, connecting means therebetween comprising an operating coil, of an overload device ,foropen ng the circuit of the operating coil upon a transfer ofexcess current between the two sections, and red sing'means comprising a Wheatstonebridge circuit for measuring the-resistance of either section and meansoperative under predetermined. voltage conditionsin both sections for directly effecting the energization of the operatin coil and operative under other. voltageco itions for effectin'g theenergization of the operating coil denamethis fith day of Septembefi regordlessof thewoltige In testimony whereofg i 'havehereuntosubr are not connected by

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