US2836769A

US2836769A - Reclosing circuit breaker

Info

Publication number: US2836769A
Application number: US590135A
Authority: US
Inventors: Sandin Jerome
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1956-06-08
Filing date: 1956-06-08
Publication date: 1958-05-27
Anticipated expiration: 1975-05-27

Description

` May 27, 195s J. SANDIN RECLOSING CIRCUIT BREAKER Filed June 8, 1956 event of simultaneous United States Patent O RECLSING CERCUIT BREAKER Application June 8, 19556, Serial No. 590,135 s claims. (ci. 317-22) My inventionrelates generallyy to circuit interrupters, audit has reference in particular to multipole reclosing circuit breakers.

Generally stated, it is an object of my invention to provide a polyphase time delayed recloser which is simple and inexpensive to manufacture, and is reliable in operation.

More specifically, it is an object of my invention to provide for using a single time delay device with any one of a plurality of trip devices of a polyphase circuit interrupter.

Another object of my invention is to provide in a multipole recloser for so connecting a'plurality of trip devices to a common time delay element, that only one trip device at a time is effective to operate the time delay device, whereby tripping action by simultaneous faults on a plurality of poles is prevented.

Yet anotherk object of my invention is to provide in apolyphase circuit interrupter having a plurality 'of overcurrent trip devices for operatively connecting them to acommon time delay device so that only one of the overcurrent devices at a time is ei'lective to operate the time delay device to open the interruptor.

It is also an object of my invention to provide in a multipole recloser for using an overcurrent trip element with each pole of the recloser, and for mechanically connecting the trip elements to a common time delay device for selectively operating the delay device in response to operation of one and only one of the overcurrent elements, so as to avoid variations in time delay such as caused by two or more trip elements acting simultaneously on a single delay device.

It isalso an important object of my invention to provide in' a multipole recloser for using a plurality of overcurrent trip devices, and for so connecting them to a single time delay device as to render all but one of them ineffective to operate the time delay device in the faults on each of the poles.

Other objects will, in part, be explained hereinafter and will, in part, be obvious.

When a time delay device is used with each pole of a multipole recloser, the delay of any one of the poles is independent of the others and depends only on the current passing through the pole in question. However, when only one delay device is used, it is necessary to have a mechanical arrangement which will allow only one overcurrent device to operate the time delay device whether the overcurrent passes through one or more poles, since if two or three overcurrent devices were to act on asingle time delay device the delay would be less than if only one overcurrent device acted.

By using an arrangement with a single time delay device, relatively expensive items such as silastic diaphragms, timer and reset valves, molded parts, and calibration of two time delay devices can be omitted while adding only less costly and lesser numbers of parts in the ice form of triggers and brackets of a mechanical arrangement according to my invention.

In practicing my invention in accordance with one of its embodiments, a three-phase recloser has three pairs of separable contacts with a single operating means springbiased to open the contacts, and held in the closed position by means of a releasable toggle linkage. Separate overcurrent trip elements are provided 'for each pair of contacts. These trip elements are operatively connected to a single time delay device in a mechanical cascade arrangement, so that of the trip elements energized, the nearest trip element to the time delay device disconnects those that are more remote, and prevents them from iniluencing operation of the time delay device to release the toggle linkage and open the contacts. This results in only a single trip element being effective at any one time to operate the time delay device, so that the time delay is not varied by reason of overcurrents occurring on two or more of taneously.

For a more complete understanding of the nature and scope of my invention, reference may be made to the iollowing detailed description which may be read in connection with the accompanying drawing, in which:

Figure l is a schematic diagram of a multipole recloser embodying the invention in one of its forms;

Fig. 2 is a plan view of a connecting mechanism for connecting the trip elements to a single time delay device;

Fig. 3 is an end view in elevation of the connecting mechanism shown in Fig. 2; and

Fig. 4 is a front view in elevation of the connecting mechanism of Figs. 2 and 3.

Referring to Fig. l, the reference numeral 10 denotes a reclosing circuit breaker of the polyphase type having pole unit contacts A, B and C connected in circuit with the

conductors

11, 12 and 13 of a three-phase circuit. The circuit breaker is substantially of the type shown in the copending application Serial No. 587,691 of JOhnB. MacNeill et al. and has pole units A, B and C which may be mechanically connected, being herein shown as connected to an insulating connecting rod 15 which is pivotally connected to the operating lever 16 of an operating mechanism 18. The lever 16 is pivotally mounted lby means of a support pivot 19, and connected to the rod 15 by means of a pivot 20. A spring 22 which rests against a support 24cooperates with a rod 25, and

cap 26 to bias the lever 16 in a clockwise position for opening the poles A, B and C.

The lever 16 is maintained in the position shown, against the bias of the spring 22, by means of toggle links 27 and 28 which have a common pivot 29 maintained in an overcenter toggle relation against a stopk 30.

The lever 28 is pivotally connected at 31 to a latch lever 32 which is pivotally mounted by a support pivot 34. A spring 35 biases the pivot 31 to collapse the toggle levers 28 and 32. The latch lever 32 is prevented from rotating in the clockwise direction by means of a releasable latch 36. This latch is held in the position shown by means of toggle levers 37 and 3S, lever 37 being connected to a fixed pivot 40.

A trip lever 42 is provided for actuating the common pivot 43 overcenter to release the latch 36. The trip lever 42 may be actuated by a trip bar 44 which is disposed to be lifted by means of any one of a plurality of

overcurrent solenoids

46, 4S and 50 having

armatures

51, 52 and 53 operatively connected through a connecting mechanism 55' and a resilient lost-motion connection 56 including a compression spring 57, to a time delay device 58, which may be of the dashpot type, for lifting a trip rod 60 having a projection 62 extending beneath the poles of the recloser simul? the trip bar 44. The time delay device 58 is provided with a dashpot control valve 64 disposed to be actuated to the open or venting position in which it is shown, by means of a control bar 65 and a lever 66 which is actuated to the position shown by means of a cam 67 on a counter member 63, which is cumulatively advanced by means of ,pawl 70 in response to movement of the operating lever 16.

Reclosing of the recloser is effected by means of a motor 72, which actuates a rotatable arm 73 having a roller 74 at the end thereof to engage a closing lever 7S movable in a guide collar 76 and connected to the common pivot 29 of the toggle levers 27 and 23. The motor 72 may be energized from a transformer 78 connected to the

conductors

12 and 13, through aflockout switch '79, which is opened by the counter member 78 after a predetermined number of closely successive operations of a mechanism, and through a reset switch 80 which is closed after a time delay, through a time delay device v82 in response to opening movement of the operating lever 16. A control switch 84 actuated by the motor 72 is connected in parallel with the reset switch 80 to act as a limit switch in bringing the motor 72 to a stop at the end of the closing cycle. A manual control switch 85 is provided for reclosing the recloser after the lockout switch 79 has been operated.

Current transformers

87, 88 and 89 are connected in parallel to the operating solenoid 90 of a ground fault current trip relay 92 for actuating a trip rod 93 with a projection 94 located under the common trip bar 44.

Referring to Figs. 2, 3 and 4, it will be seen that the connecting mechanism 55 may comprise a plurality of

connectors

96, 9,7 and 98 pivotally mounted in side-byside relation on a common shaft 99 and arranged to be releasably connected in cascade. The connector v96 is provided as shown in Figs. 2 and 3, with an arm 100 projecting horizontally to one side of the shaft and connected by means of a pivot 101 to the time delay device 584 through a lost-motion connecting device 56 for resiliently lifting the projection 62 to operate the trip bar 44 which, as shown in Fig. 1, trips the operating mechanism 18. The connector 96 is also provided with an arm 102 projecting horizontally to the other side of the shaft 99. This arm 102 is provided with a substantially triangular-shaped trigger 104 which is pivotally mounted at one apex ,adjacent the end of the arm 102 by means of a pivot 106. Alaterally projecting lug or stop 105 on arm 102 and a depending tab 103 on trigger 104 limit rotation of the trigger as shown in Fig. 3. The armature 51 of pole A is operatively connected to the trigger 104 at another apex by means of a rod 107 having a slot 108 at the upper end to receive a pin 110 projecting from the trigger 104. A recess 112 is provided adjacent the third apex on the upper end of the inner side of the trigger 104 for effecting a releasable connection of the connector 97 of pole B with connector 96.

Connector 97 is provided with an arm 115 adjacent arm 102 which projects angularly upwardly on the same side of the shaft and has a pin 116 projecting laterally therefrom so as to be normally positioned in the recess 112 of the trigger 104 to permit the arm 115 to thereby move the connector 96 in a counterclockwise direction. The connector 97 is also provided with a substantially horizontally projecting arm 1.18 at its other end, corresponding to the arm 102 of connector 96. This arm is likewise provided with a trigger 120 which is pivotally mounted on the arm by means of a connected to armature 52 of solenoid 48 by means of a connecting rod 123 through a slotted connection similar to that of rod 107. l

The connector 98 is provided with an angularly-projecting arm 125 similar to arm 115, at the end adjacent the arm 118, and the arm 125 is provided with a pin 126, which like the pin 116 of arm 115, is disposed to engage a recess in the trigger 120 providing a releasable connecpivot 121 and is to release pin 116. The

tion between the

connectors

98 and 97. At its other end, the connector 98 is provided with a substantially horizontally projecting arm 128 corresponding to the arm 118 of connector 97. A pin 131 adjacent the end of arm 128 provides a lost-motion connection with a connecting rod 133 connected to the armature 53 of solenoid 48, in a manner similar to that described for the connecting rod 107.

Whenever an overcurrent occurs, the

armatures

51, 52 and 53 will be selectively actuated, depending in which one er' the

conductors

11, 12 and 13 the overcurrent occurs. When a three-phase overload occurs, the

armatures

51, 52 and 53 will each be actuated to pull their connecting

rods

107, 123 and 133, respectively, downwardly. Downward movement of rod 107 rotates the trigger 104 in a counterclockwise direction about pivot 106 until the edge of trigger 104 engages stop 105. The pin 116 is freed from the recess 112, permitting the connector 97 to be rotated in a counterclockwise direction free of the connector 96. Further, downward movement of rod 107 rotates the connector 96 in a counterclockwise direction, lifting the projection 62 either instantaneously or against the delaying action of the time delay device 58, depending on the position of valve `rod 64, and actuating the trip bar 44 to move the trip lever 42 in a clockwise direction and open the recloser. At the same time, downward movement of the connecting rod 123 rotates the trigger 120 on pivot 121, and releases the pin 126 of connector 98 so that movement of the

armatures

52 and 53 will individually actuate their

connectors

97 and 98 without effecting operation of `the time delay device 58. The triggers and levers may be reset by means of suitable springs or the like biasing them to the positions shown, such as

springs

122 and 124 for example.

Overloads on poles A and B, in a similar operation,

or A and C will result

rod

123 or 133, as the case may pole is not energized, will not be each instance, the trigger of the pole which is energized, that is pole A, will disconnect the mechanisms of poles B and C so that only pole A operates the time delay element 58.

Overloads on poles B and C will cause the armatures 52 and l53 of the poles B and C to be actuated, thus pulling connecting

rods

123 and 133 downwardly. Downward movement of rod 123 rotates trigger 120 to release the connector 98 so that it operates free of the time delay device. Connector 97 is rotated by downward movement of rod 123, and pin 116 remains in the recess 112 of trigger 104, thus causing rotation of the connector 96 in the same direction, so as to actuate trip projection 62 through the time delay device 58. Since pole A is lnot energized, the rod 107 does not move, and pin moves downwardly in the slot 108 as the connector 96 rotates.

If an overload occurs on pole B only, the

connectors

97 and 96 will rotate together in the manner lhereinbefore described, but since pole C is not energized, the connector 98 will remain stationary. When an overload occurs on pole C, only the rod 133 is pulled downwardly,

rotating connectors

98, 97 and 96 together as a unit, to operate the time delay device 58 to trip the recloser.

Whenever'the trip lever 42 is moved in a clockwise direction to break the toggle connection of

levers

37 and 38, latch 36 is disconnected from the latch lever 32 4so that pivot 31 is moved by spring 35 to the right, thus permitting pivot 29 to move to the -left and the recloser poles A, B and C to open under the` action of the spring 22.

Initial opening action ofthe recloser is instantaneous, since the cam 67 holds the lever 66 in a position with the valve rod 64 held down in the open or venting position, so that the projection 62 is moved almost immediately to operate the trip bar 44. Opening of the be depending on which pulled downwardly. In

and trigger 104 will be rotated recloser causes the pawl 70 to actuate the counter member 68 to advance it one step, in which the cam 67 still holds the lever 66 in the position shown. A predetermined time after the reclosure opens, switch 80 closes and provides an operating circuit for the closing motor 72, which operates to rotate the arm 73 in a counterclockwise direction. The roller 74 engages closing lever 75 and moves it longitudinally to the right, returning the levers 27 and 28 to the overcenter position shown and rotating the operating lever 16 in a counterclockwise direction to compress the opening spring 22 and close the poles A, B and C.

Upon the second operation of the recloser, the counter member 68 is advanced a. second step, whereupon the cam 67 is moved out from beneath the lever 66 permitting the lever to rotate in a clockwise direction and permitting the valve member 64 to rise to the closed position to which it is biased. Subsequent operations of the

solenoid armatures

51, 52 and 53 will thus be retarded by the delay action of the time delay device 58 to provide delayed operation of the trip bar 44 and delayed opening of the recloser. At the end of a predetermined number of operations, four operations, for example, the counter member 68 is advanced sufficiently to open the lockout switch 79 and prevent completion of the operating circuit for the motor 72. The poles A, B and C will remain open until the operating mechanism 18 is either reclosed manually or through the operation of the control switch 85.

From the above description and the accompanying drawing, it will be seen that I have provided in a simple and effective manner for utilizing a single time delay device for opening the three poles of a recloser in response to overcurrents on any one or more of the poles. Since only one of the overcurrent solenoids at a time is able to act on a time delay device, plural phase faults will not effect the timing of the time delay device, so that more consistent operation will be obtained. Only a single time delay device is thus necessary for a multipole recloser, and the problem of variations in t-he timing characteristics of different time delay devices effecting operation of the different poles is thus obviated.

Since certain changes may scribed construction, and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the above description and shown in the accompanying drawing shall be considered as illustrative and not in a limiting sense.

I claim as my invention:

l. In a circuit interrupter, a plurality of pairs of separable contacts, electroresponsive means individual to each pair of contacts, means including a single time delay device operable to effect separation of said contacts, and means operatively connecting the electroresponsive means to the delay device including releasable means selectively operable to provide an operative connection for but one of the electroresponsive means to the delay device.

2. In combination, separable contacts, operating means for said contacts, a plurality of overcurrent actuated devices, means including a single time delay device operable to delay operation of the operating means to separate said contacts, and means mechanically connecting the overcurrent devices to the delay device including releasable means normally connecting the overcurrent devices to the delay device in cascade, said releasable means being operated by their respective overcurrent means to release each overcurrent means except one from the delay device.V

3. In combination, separable contacts, operating means therefor including releasable means normally holding said contacts closed, a plurality of overcurrent devices, means including a time delay device common to the plube made in the above-derality of overcurrent devices operable to delay release "6 of the releasable means, and means connecting the time delay device and overcurrent devices including a member individual to each overcurrent device, means connecting one of said members to the delay device, and means providing a lost-motion connection between the overcurrent devices and their respective members and a releasable connection betweenits respective member and an adjoining one of the other members.

4. A circuit interrupter comprising, separable contacts', operating means therefor including a spring biasing said contacts to separate and releasable means holding said contacts closed, normally ineffective time delay means, means reclosing said contacts following separation, means actuated by closely consecutive separations of the contacts to render the delay means elective, a plurality of overcurrent devices, connecting means selectively connecting the overcurrent devices and the delay means to effect operation of the delay means by no more than one of the overcurrent devices, and means -operating said releasable means upon operation of the time delay means.

5. The combination in a circuit interruptor, of a plurality of pairs of separable contacts, a single operating means for said contacts including a common means biasing said pairs of contacts to separate, releasable means latching the operating means to prevent separation of said contacts, overcurrent means individual to each pair of contacts, a lever individual to each pair of contacts, and means including an additional lever carried by each of said rst-mentioned levers providing a lost-motion connection between each overcurrent means and its associated one of said levers, means movable with at least one of said first-mentioned levers releasably engaged by the additional lever of an adjacent lever, and means operable by one of said first-mentioned levers for actuating said releasable means.

6. The combination in a circuit interrupter, of a plurality of pairs of separable contacts, operating means for said pairs of contacts including a spring biasing the operating means to separate said pairs of contacts simultaneously, releasable means normally holding said operating means with the contacts closed, means actuating said operating means to reclose said pairs of contacts after separation, means including a time delay device operable to release said releasable means, an overcurrent actuated device individual to each pair of contacts, a plurality of levers pivotally mounted on a shaft in side-by-side relation, means including an additional lever pivotally mounted on each of said levers providing a releasable operable connection with an adjacent one of said levers, means connecting the time delay device to one of said levers, and additional means providing a lost-motion connection between the overcurrent actuated means and said additional levers associated therewith.

7. In a circuit interrupter, a plurality of pairs of separable contacts, operating means for said contacts including a common operating member, a spring biasing said member to separate said pairs of contacts, releasable means holding said member in a contact closed position, trip means operable to release said releasable means including normally ineective time delay means, a counter advanced by closely successive separations of said contacts to render the delay means effective after a predetermined number of closely consecutive contact separations, means operable to reclose said contacts after separation, overcurrent means individual to each pair of contacts actuated by a predetermined overcurrent, and means releasably connecting the overcurrent means to said delay means including a plurality of rocker levers disposed in side-by-side relation on a common shaft, means connecting a first one of said rocker levers to actuate the delay means, a catch mounted on a second and third one of said levers, releasable latch means mounted on the iirst and second one of said levers to releasably engage the catch of the second and third levers respectively, and means providing a lost-motion connection between the overcurrent means, and the Elateli means of the rst and secondlleversand the third 4one .of said levers respectively.

8. AIn amultipolelelectrical device, switching means for each vof a `plurality of the poles ,of :the device, V,electroresponsive means individual y to leach .of a plurality of the poles :of -the device, means including a Ysingle time .delay device operable to delay `operation of saidA switching means, and selecting means Spera-ble :upon Operation of any one or more of said electroresponsive means select- 111g one and only .one of said electroresponsive means .to 10 2785347 Operate `said `single time delay device independently of the `other elecItoresponsi-ve means and eiect operation of said switching means.

References Cited in the le vof this patent UNITED STATES PATENTS 2,738,394 Matthews Mar. 13, 1956 2,752,452 Rawlins June 26, 1956 Tremblay Mar. 12, l1957