US1786324A - Periodic-reclosing circuit-breaker system - Google Patents

Description

Dec. 23, 1930. l R J, WE SL 1,786,324

PERIODIC RECLOSINQ CIRCUIT BREAKER SYSTEM Filed April 16, 1925 5 Sheets-Sheet l 4 INVENTOR w a q V I 7 50y wens/6y. 7 m

r ATTORNEY Dec. 23, 1930. J WENSLEY 1,786,324

PERIODIC RECLOSING CIRCUIT BREAKER SYSTEM Filed April 16, 1925 5 Sheets-Sheet 2 F/g Z.

WITNESSES: INVENTOR flMM 50y M. wens/ y p/l/Zl ATTORNEY Dec. 23, 1930. R J, WENSLEY 1,786,324

PERIODIC RECLOSING CIRCUIT BREAKER SYSTEM Filed April 16, 1925 3 She ts-Sheet 3 2 I I I WITNESSES: 30 I 1!NVENTOR 1 7/ r ----1 a2 180 1/ wens/6y.

AT I'ORNEY v Patented. Dec. 23,

UNITED STATES PATENT orr ce BOY J. wnnsnmz, or nnenwoon, 'rmmsxnvmm, ASSIGIliOB 'ro wnsrnt'enousn m 'rnrc a umurncrunme comraux, n conroan'rron or rmmsnvmn rnmonrc-nncnosme omcurr-nnmm sxs'rml Application filed April 10,

permitting the relay to reset itself in its in itial position under different external conditions.

'A further obj ect' of my invention is to provide a system'of control for an automatically as reclosing circuit breaker system that shall be operative tocontrol the operation of the system through a predetermined cycle if abnormal conditions on the system be of a persisting nature, and that shall be operative if the v 2 abnormal conditions are of a temporary nature, to effect the reclosure of the system and then to reset itself in its initial position.

Another object of my invention is to provide a relay in a system of the above-indicated character, that shall render itself inoperative to proceed beyond a predetermined point in the cycle of operation for which it is adjusted, and that shall always reset itself at its initial, position when external conditions in the associated circuit are cleared before the relay has operated throughout the complete cycle for which it is adjusted.

A further object of my invention isto provide a system, of the above-indicated character, whereby a circuit, interrupter shall be reclosed a predetermined number of times "at redetermined intervals after the first opening of the interrupter by reason of an abnormal or faulty condition in the circuit, and that shall preclude further automatic operation of the interrupter if the faulty condition is not eliminated during the predetermined cycle including such operations.

A still further object of my invention is to provide a system of the above-indicated 192's. Serial in. 832,502.

character that shall be simple in construction and fully automatic andreliable in its operation.

In practicing my invention, I provide means for opening the circuit interrupter to disconnect a feeder circuit from its supply circuit upon the occurrence of abnormal conditions in the feeder circuit. Since it is possible that the faulty condition may be a temorary one, I also provide a relay that emdies means for automatically effecting the reclosure of the interrupter a predetermined number of times, for exam le, three times, at predetermined intervals a r the first opening thereof. If thefaulty condition clears after the first or second reclosing, but before the third reclosin the interrupter will remain-closed and t e relay will reset itself at its initial position. to be ready for operation if a faulty or abnormal condition should again'occur. j e v If the faulty condition which caused the opening of the interrupter the first time should persist, after the interrupter has been reclosed three times, and'should effect the opening of the interrupter afte'rthe third reclosure, an auxiliary relay would then be rendered effective to lock out the feeder circuit by precluding further automatic operation of the circuit interrupter It would then be necessary to reclose the interrupter manually, which would be efi'ected only after. the faulty condition had been eliminated.

The relay which I employ comprises an ordinary relatively high-speed motor of the fan type and a cylindrical drum upon which are mounted contact segments arranged to effect a predetermined cycle of operations in an external circuit. The drum is rotated in either direction, according to the direction of rotation of the motor, through gears of suitable size, to provide a desired time interval of operation after a complete rotation of the drum. The motor is provided with two windings to control its rotation in either direction. Stationary contact members are mounted on the frame adjacent to the drum and are adapted to be selectively engaged by the various contact segments disposed on the drum to control the external circuits asso- 100 ciated with the control equipment of the interrupter.

Figure 1 of the accompanying drawingsls a diagrammatic view of an electrical system in which the relay embodying my invention has its particular'application.

Fig. 2 is a front elevational view of the re la ii ig. 3 is a side view, in elevation, of the relay that is shown in Fig. 2.

Fig. 4 is a front elevational view of tl e drum showing the arrangement of the limit switch of the motor and the controlling contact segments for the external circuits, and

Fig. 5 is a plan view of a contact segment consisting of a single member for controlling the external circuits associated with the mterru ter.

Re erring to the accompanying drawings, energy is derived from a supply circuit 1 and transmitted to a feeder or load circuit 2 through a circuit-controlling device or interrupter 3. While the feeder circuit is in nor mal condition, it is connected to the supply circuit 1. Upon the occurrence of abnormal conditions therein, such as may be caused by short-circuit or excessive overload, a trip coil 4 is energized from a current transformer 5 to open the interrupter 3, thereby disconnecting the feeder circuit from the su ply circuit.

ince the faulty condition that caused the actuation of the interrupter, to disconnect the two circuits, may be merely temporary, it is desirable to automatically eiiect the reclosing of the interrupter without waiting until an inspector may discover that the feeder circuit is disconnected from the supply circuit.

In order to effect such reclosure, I provide a motor-driven relay 7 comprising a motor 8, a circuit-controlling member 9 serving as a timing means and a circuit-controlling member 10 serving as a limit switch. I provide also a relay 11 for controlling the circuit of the closing coil 12 of the interrupter and an auxiliary relay 13 for controlling the energization of the closing coil of relay 11. A manually-operable control switch ltis provided to control the interrupter 3 manually and to suspend the automatic operation of the system, when desired.

The motor 8 comprises two opposing field windings 15 and 16 whereby the direction of rotation may be reversed. The circuits of these windings are respectively controlled by the limit switch 10 in conjunction with two interlock switches 17 and 18 that are 0perated and controlled by the circuit interru ter 3.

he limit switch 10 comprises three stationary contact members 20, 21 and 22 and a bridging member 24 so constructed, as illus trated in the accompanying drawings, as to permit the engagement of the contact members 21 and 22 while the switch is in its initial position.

The timing means 9 comprises three stationary contact members 25, 26 and 27 that are adapted to be engaged by the associated bridging portions, as illustrated in the drawings. The contact member 25 is adapted to engage portions 28, 29, and 30 in succession while the contact member 27 engages contact members 31, 32 and 33 in succession. The contact member 26 will engage all of said portions in succession. The contact member 25 will be engaged by the bridging 'member 28 somewhat before the contact member 27 will be engaged by the bridging portion 31.

By properly proportioning the gear ratio between the motor and the drum, upon which the timing means 9 and the limit switch 10 are mounted, any desired interval of time may be obtained for one complete cycle of operation of the relay. Similarly, by properly spacing the bridging portions 31, 32 and 33, any desired time intervals for reclosure of the interrupter 3 may be obtained. For example, the portions 31, 32 and 33 may be so spaced as to procure a reclosing interval of thirty seconds for the first reclosure, a second interval of one minute between the reopening after such reclosure and a second reclosure, and a third interval of two minutes between the subsequent opening and the third reclosure.

While I am specifying intervals of onehalf minute, one minute and two minutes by way of example, it is obvious that any desired timing intervals may be secured, by properly spacing the bridging portions 31, 32 and 33. Moreover, any number of reclosures may be eiiected by providing a corresponding number of contact portions to engage the contact members 25, 26 and 27.

Relay 13, which serves to control the energization of the closing coil 12 to open the circuit thereof after the interrupter is closed each time, and also to preclude further energization of the closing coil when a faulty condition persists, .is provided with two switches 34 and 35, an operating coil 36 and a reset coil 37. The operating coil 36 is controlled by the timing bridging portions 31,

32 and 33 in conjunction with the contact member 27 and by a switch 39 that is operated and controlledby the interrupter 3.

The reset coil 37 is similarly controlled by the bridging portions 28, 29 and 30 and a switch 40 that is controlled by the interrupter 3.

The control switch 14 comprises a switch 41 for controlling the closing coil relay 11,

pend automatic operation of the control system.

switch 1-1.

The switch 43 is normally closed when the control switch 14 is in neutral osition. When the control switch is move to trip position to close the switch 42, the switch 43 is opened and maintained open until the switch 1 2: is moved to closed 53051111011 to close The interrupter 3 is closed by moving the control switch to close switch l1. The closing coil relay 11 is then energized through the switch 45 of a lockout relay 46 to complete the circuit of the closing coil 12. The

Y switch 39 is closedby the interrupter 3, when closed, and cooperates with the switch 41 of the control switch to energize the operating.

only to abnormal currents of predetermined values and normally remains in its de-energized position, A switch 50 is provided to reset the relay electrically. I

Upon the occurrence of abnormal conditions in the circuit 2 that cause excessive currents to traverse the circuit, the trip coil 4 1 becomes suficiently energized from the current transformer 5 to open the interrupter 3, The interrupter 3, in opening, closes switches 18 and 40. Switch 18 co-operatcs with contact members 21 and 22 and the bridging member 2% of the limit switch to energize the motor 8 in such direction as to move the v scribed, efiects the engagement of the switch drum in a forward or downward direction.

The energizing circuit for the motor 8 extends from the left-hand terminal of the supply. source, through switch 43, contact members 21 and 22-bridged by the segment 24-switch members-18, forward field winding 16, armature of the motor 8 and contact members 45 of the switch 46, to the other terminal of the supply source. the drum commences to move, the contact member 20 is engaged by .the bridging member 24 oi the limit switch 10. Subsequently the bridging portion 28 engages contact members 25 and 26 and co-operates with switch 40 of the interrupter to energize the reset coil 37 of the'relay 13.. The circuit for energizing the reset coil 37 of the relay 13 may be traced from the left hand supply conductor, through switch 43, contact membore 25 and 26bridged by the segment 28 contact members 34E of the relay 26, reset coil 37, switch members 40 of the interrupter 3, and contact members 45 of relay 4:6, to the supply conductor. Since the. ener gizing circuit for the operating coil 36 of the relay 13 is interrupted at theswitch 39 when the interrupter 3 opens, the energizetion of the reset coil 37, as hereinbefore demembers 35. The switch 35 is thereupon rcclosed. 1

, 'lhirty seconds after the interrupter is opened, the portion'31 of the timing means 9 engages the contact members 26 and 27. The relay 11 is thereupon energized to close the circuit of the closing coil 12 and the inter terrupter and the closing of its auxiliary switch 39, the operating coil 36 of the relay 13 is energized to open the switch 35 which is thereupon latched in its open position by the latching member 44 of the relay 13 The circuit of the closing coil is thus opened after each closure of the interrupter.

li the faulty condition has been eliminated before the interrupter 3 is reclosed, the interrupter will remain closed and the motor will be energized by means of the switch 17 through the contact members 20 and 21 and the bridging member 24: of the limit switch 10 to ed'ect the operation of the relay 7 in the reverse direction until the contact mem ber 20 is disengaged by the bridging member 24-. The motor 8 is reversed by the completion of a circuit which extends from the left supply conductor, through switch 13, contact members 20 and 21-bridged by the segment 2 l--switch members 17, reverse field winding 15, armature of themotor 8, and contact members 45 of relay 36. to the other supply conductor. Under such conditions,

the motor will be deenergized and the relay will remain in such position until the occurrence of another faulty condition which will require the automatic reclosing of the interrupter. Shortly after 1f th faulty condition has i not been cleared, the interrupter will immediately be reopened, depending upon the time setting;

of mechanism associated with the trip coil 4 and, instead of the motor being energized through the switch 17 to reverse its direction, it will continue to be controlled by the switch 18 to effect its operation in the forward direction. The bridgingportion29 of the timing means 9 will then engage the contact member 25 and co-operate with the switch 40 of the interrupter to energize the reset coil 37 of the relay 13. The main switch 35 of the relay 13 will thereupon be closed, and, after an interval of substantially one-minute, depending upon the spacing between the-bridging portions 31 and 32, the relay 11 will again be energized to efl'ect the reclosing of the interrupter 3.

As previously explained, if the line should now be cleared of abnormal conditions, the motor will reverse its operation and reset itself in its initial position. If, however, the

faulty condition persists, the interrupter will immediately reopen and the motor will continue in its forward direction. After an interval depending upon the spacing between the portions 32 and 33, the interrupter will be reclosed a third time and the relay 13 simultaneously operated to open the switch 35 and de-energize the clos'ing'ooil of relay 11.

When the interrupter opens again after the third reclosing, the motor 8 continues to move in the forward direction until the contact member 22 is disengaged by the bridging member 24. The motor 8 is thereupon deenergized and will remain in such position until the interrupter 3 is closed manually or by means of the switch 41 after the faulty conditions have been eliminated. The relay 8 will then reset itself in its initial position in which it is illustrated in the drawings.

When it is desired to open the interrupter 3 and to suspend the automatic operation of the'control system to permit working on the interrupter 3 and on the feeder circuit 2, the

switch 43 is opened.

As illustrated in-Figs. 2 and 3, the motor of the relay is supported on a base 61 that is provided with a laterally extending bracket 62 of channel shape between the sides of which the drum 63 is supported and permitted to turn, as controlled by the motor 8, through the gears 64 and 65. a

The stationary contact members 20, 21, 22 and 25, 26, 27 are mounted on a supporting bracket 66 which is secured to the edges of the sides of the channel-shaped bracket 62.

Extra gears 67 and 68, having different ratios, are provided to be substituted for the gears 64 and if a different speed of rotation is desired to vary the time interval of operation of the drum.

By means of the self-resetting relay in the system which I have described, I am'able to effect the automatic reclosure of a circuit interrupter a predetermined number of times at predetermined intervals after the occurrence of an abnormal condition in the circuit and to preclude further automatic operation of the interrupter if the abnormal condition persists after a predetermined cycle of re closing operations.-

My invention is not limited to the specific apparatus that I employ nor to the particular arrangement that I have illustrated, since modifications both in the structural and timing features of the apparatus may be made without departing from the spirit and scope of my invention, as set forth in the appended claim. r

I claim asmy invention:

1. A self-resetting device for controlling the operation of a circuit interrupter provided with a two-position interlock switch,"

comprising a motor operative iii-two directions, windin s for controlling the movement of the motor in either dilectign and a swit chthat is actuated to either of two positions depending upon whether the interrupter is open or closed, of a controllin device therefor comprising a motor rotata le in both directions, means for actuating the motor in either direction and means co-operating with the interlock switch to control the energization of the actuating means to effect rotation of the motor in a predetermined direction depending upon the position of the interlock switch.

3. The combination with a circuit interrupter provided with aninterlock switch that is actuated to either of two positions depending upon whether the interrupter is open or closed, of a controlling device therefor comprising a motor actuable in two directions, two windings severally operative to actuate the motor in either direction, a switching device controlled by the motor to control the operation of the interrupter, and means controlled by the motor and cooperating with the interlock switch of the interrupter to con trol the operation and position of the motor.

The combination with a circuit interrupter provided with an interlock switch that is actuated to either of two positions depending upon whether the interrupter is open or closed, of a controlling device therefor comprisin a motor actuable in two directions, two windings for severally controlling such directional actuation between twolimits of position and means dependent upon the position of the motor and of the interlock switch of the interrupter for controlling the windings to actuate the motor to one of the limits.

5. The combination with a circuit interrupter provided with an interlock switch that is actuated to either of two positions depending upon whether the interrupter is open or closed, of a controlling device therefor comprising a motor actuable in two directions and means co-operating with the motor andthe interlock switch of the interrupter to control the operation of the interrupter in a predetermined manner and the operation of the motor in a direction depending upon the position of the interrupter.

6. The combination witha circuit interrupter provided with an interlock switch that is actuated to either of two positions depending upon whether the interrupter is open or closed, of a controlling device therefor comprising a motor actuable in two directions, a switch controlled thereby to effect the actuation of the interrupter only while the motor moves in one direction, and means-dependent upon the position of the interrupter for resetting the motor in its initial positionor rendering it inc erative to proceed beyond a predetermine position in the efiective direction.

7. The combination with a circuit interrupter i provided with an interlock switch that is actuated to either of two positions, de-

pending upon whether the interrupter is open or closed, of a controlling device therea time,

8. In combination, a circuit interrupter, means for tripping the same under predetermined condltions, and means for automatically reciosing the circuit interrupter, said last-mentioned means comprising a reversible motor, a contact member actuated thereby,

' and means for actuating the motor to reset the contact member in itsinitial position if the circuit interrupter remains closed for. an. appreciable period 9. In combination, a circuit interrupter, means for tri ping the same under predetermined conditions, and means for automatically reclosing the circuit interrupter a predetermined number of times, said last-meme tioned means comprising a motor, circuitclosing devices actuated by the motor, and means for actuating said motor to reset said devices in the initial position if the circuit interrupter remains closed.

10. In combination, acircuit interrupter, a controlling device therefor comprising a motor, a switching device actuated by the motor to control the operation of the interrupter, and means jointly controlled by the positions of the interrupter and the switching device for energizing said motor to pro vide the desired actuation of said motor and switching device:

11. In a power-distributing system, the combination with a supply circuit, a load circuit and a circuit interrupter therebetween, of means responsive to current-in the load circuit for opening the interrupter and means for automatically reclosing the interrupter a predetermined number of times after an opening thereof by said current-responsivemeans, said reclosing means comprising a timing device having successive didering time intervals oi operation.

12. In a power-distributing system, the combination with a supply circuit, a load circuit and a circuit interrupter therebetween, of means responsive to current in the load circuit for opening the interrupter and means for automatically reclosing the interrupter a predetermined number of times after an opening thereof by said currentopening.

responsive means, said reclosing means comprising a closing coil, switching means for efiecting energization of the circuit thereof at predetermined difiering time intervals after the openin of the interrupter, actuating meansior t e switchin means, electromagnetic means ior contro ling'said actuating means and means controlled by the" interrupter for controlling the electromagnetic means. 13. An automatically reclosing system for a circuit interrupter provided with a tripping and closing mechanism, comprising'means for actuating the tripping mechanism uponthe occurrence of abnormal current conditions in a circuit to be controlled,*clectro-.

magnetic means for actuating the closing mechanism, a control switch therefor, means for rendering said switch inefi'ective after each closure of the interrupterand a timing means for controlling the automatic reclosing of the interrupter a predetermined number of times aiteran automatic opening'thereoi by reason of the aforementioned abnormal conditions, said reclosings being efiected after predetermined intervals following each ll. In a power distribution system, the combination with a supply circuit, a load (El-Z? cult and an interrupter therebetween, of means for opening the interrupter upon the occurrence oi an abnormal condition in the load circuit, and reclosing means therefor comprising a motor operative in two directions, a timing switch controlled thereby and a limit switch for controlling the motor.

15. In a power-distribution system, the combination with a supply circuit, a load circuit and an interrupter therebetween, of

means for opening the interrupter upon the occurrence of an abnormal condition in the load circuit, and reclosing means therefor comprising electromagnetic means operative in two directions,.means operative as a timing switchcontrolled thereby, means operative as a directional switch also controlled by said electromagnetic means, and switching means controlled by the interrupter and cooperating with the directional switch to control the electromagnetic means.

16. In a power-distribution system, the combination with a supply circuit, a load circuit and an interrupter therebetween, of

means for opening the interrupter upon the occurrence of an abnormal condition in the load circuit, and reclosing means therefor comprising a motor operatiye in two directions, switching means serving as a timing device for controlling the closing of the interrupter, switching means controlled in effectiveness by the interrupter and operative to control the operation of the motor depending upon the actuation of the timing device.

17. In combination, an electric circuit, a circuit breaker in said circuit, means responiao sive to a predetermined condition of said circuit for efiecting the opening of said circuit breaker, electromagnetic means for effecting the closing of said circuit breaker, a circuit for said electromagnetic means, a control re- V cuit breaker for controlling said control relay circuit to cause said role to close the contacts in the circuit of sai electromagnetic means which are controlled thereby and for subsequently effecting the closing of said other contacts in the circuit of said electromagnetic means. v

18. In combination, a circuit breaker, a control relay for said circuit breaker, switching means, a circuit for said relay, contacts in said relay circuit arranged to be closed when said circuit breaker is open, contacts in said relay circuit controlled by said switching means, electromagnetic means for effect ing the closing of said circuit breaker, a circult for said electromagnetic means, contacts in said last mentioned circuit controlled by said control relay, and contacts in said last mentioned circuit controlled by said switching means.

19. An automatic reclosing system for an electric switch comprising means to open the switch upon overload, means to close the switch including a reclosing relay rendered effective by the opening of the switch to close it repeatedly, means rendered effective by the initial opening of the switch toultimately disable said reclosing relay and leave the switch open, said means also havin self-disabling means, whereby to disable t e system until reset, and manually-operated switch closing means, said disabling means arranged to be automatically reset to operative position by the manual reclosing of the switch.

20. An automatic reclosing system for an electric switch comprising means to open the switch upon overload, means to close the switch including a reclosing relay rendered effective by the opening of the switch to reclose it repeatedly, and means includin a disconnecting relay rendered effective by the initial opening of the switch to ultimately disable said reclosing relay and leave the switch open, said disconnecting relay including contact-members arranged to control said reclosing relay, a control-member for said contact members arranged to be driven positively into a contact-controlling position and also positively into a contact-free position, means to drive said controlling member to-' ward a contact controlling position when the switch is open, and means to drive said controlling member toward a contact-free position when the switch is closed.

21. An automatic reclosing system for an electric switch comprising means to open the switch upon overload, means to close the switch including a reclosing relay rendered efi'ective by the opening of the switch to reclose it repeatedly, and means including a disconnecting relay rendered effective by the initial opening of the switch to ultimately disable said reclosing relay and leave the switch open,'said disconnecting relay including contact-members arranged to control said reclosing relay, a control-member for said contact members arranged to be driven positively into a contact-controlling position and also positively into a contact-free position, means to drive said controlling member toward a contact-controlling position when the switch is open, means to drive said controlling -member toward a contact-free position when the switch is closed, means to arrest said controlling member in a contact-controlling position whereby to disable the system and leave the switch open, and manually controlled means to reclose the switch and return said controlling member to a contact-free position.

22. An automatic reclosing system for an electric switch including means to open the switch upon overload, and relay mechanism rendered effective by the opening of the switch to reclose it repeatedly, said relay mechanism including means movable continuously'toward an operative position when the switch is open to ultimately prevent the reclosin of the switch.

23. n combination, an electric circuit, a circuit breaker for controlling the circuit, means responsive to abnormal conditions in the circuit for opening the breaker, electromagnetic means for closing the breaker, a drum switch for controlling the energization of said electromagnetic closing means to repeatedly close the breaker at predetermined time intervals, a motor for actuating the drum, and means provided on the drum switch for controlling the direction of operation of the actuating motor dependent upon the position of the circuit breaker.

24. In combination, an electric switch, means for actuating the switch, a control drum for controlling the energization of said switch-actuating means, said drum being provided with a plurality of spaced contact segments for effecting a. series of reclosing operations of. the electric switch, a motor responsive to the opening of the electric switch for actuating the control drum, and means actuated in accordance with the movements of the drum for controlling the operation of the motor to eifect a predetermined number of reclosing operations and to render'the control drum efreclosures.

25. In combination, a circuit interrupter, an operation-controlling device for the interrupter, a motor for actuating the controlling device, means for actuating the motor in forward and reverse directions of rotation, and means actuated in accordance with the controlling device dependent upon the position of the circuit interrupter for controlling the direction of rotation of the motor, thereby to perform closing operations of the interrupter and reset operations of the operation-controlling device.

26. In an automatic reclosing circuit breaker system, in combination, a circuit breaker, electromagnetic means for actuating the circuit breaker to its closed position, an energizing circuit for said electromagnetic means, a motor-operated controller for controlling the energizing circuit in response to an opening operation of the breaker, said controller being disposed to effect a series of reclosing operations of the breaker so long as the breaker continues to open, and means responsive to the closing of the breaker for rendering the motor-operated controller inefl'ective to complete the energizing circuit.

27. In an automatic reclosing circuit breaker system, in combination, a circuit breaker for controlling a circuit, means responsive to abnormal-current conditions in the circuit for effecting an opening operation of the breaker, electromagnetic means for closing the breaker, a motor-operated timing device for controlling the energization of the electromagnetic closing means,

said motor-operated timing device being disposed to efiect a series of reclosing operations of the breaker in a predetermined time sequence, and means actuated by the breaker for controlling the operation of the motor operated timing device.

28. An automatic reclosing system for a circuit breaker, comprising means operable to effect the'opening of the circuit breaker upon overload, electrically-operated means for closing the breaker, means rendered'effective by the opening of the breaker for energizing said closing means to reclose the breaker repeatedly, and means actuated by said means for energizing the closingmeans disposed to limit the reclosing operations to a predetermined number, said limiting means being disposed to cause the means for energizing the closing means to assume its initial position in the event the breaker remains closed after a reclosin voperation.

29. A control system for e ecting the au-.

tomatic reclosing of a circuit interrupter comprlsmg an electromagnetic closing mechanism for the interrupter, switching means.

operable to successively energize the electromagnetic closing mechanism at predetermined time intervals in response to successive opening operations of the interrupter,

and means actuated by said switching means for limiting the number of reclosing operations, said'means being disposed to cause the switching means to return to its initial position when the reclosing operations have been completed.

30. In a control system for eflecting automatic reclosing of a circuit breaker, in combination, an electromagnetic closing mechanism for the breaker, a motor-operated relay provided with a timing element for. controlling the energization of the closing mechanism, a reset relay interposed between the motor-operated relay and the closing means, said reset relay being actuated in response to each reclosure of the breaker to render the timin element of said motor-operated relay ine ective to close the breaker, the motor-operated relay bein disposed to effect a predetermined num er of successive reclosing operations of the breaker in response to successive openings of the breaker, means actuated by the opening operation of the breaker disposed to cooperate with said motor-operated relay to render said timing element effective and means actuated by the circuit breaker for causing the motor-operated relay to return to its initial position in the event that the circuit breaker remains closed after reclosing operation.

Intestimony whereof, I have hereunto subscribed my name this 29th day of March,

ROY J. WENSLEY.

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