US2921238A - Closing control scheme for a circuit breaker - Google Patents

Description

Jan. l2, 1960 c. E. woLLERToN CLosmc CONTROL SCHEME FCR A CIRCUIT BREAKER Filed Nov. 18. 1957 2 Sheets-Sheet 1 INE Inventor: Charles E. Wollerton, bs /f/ m,

His torneg.

Jan. 12, 1960 c. E. woLLER'ToN CLOSING CONTROL SCHEME FOR A CIRCUIT BREAKER Filed Nov. 18. 1957 2 Sheets-Sheet 2 L/NE i wl Immun! UnitedStates Patent O CLOSING CNTROL SCHEME FOR A CIRCUIT BREAKER Charles E. Wollerton, Philadelphia, Pa., assignor to General Electric Company, a corporation of New York Application November 18, 1957, Serial No. 697,031

6 Claims. (Cl. 317-22) This invention relates to a closing control scheme for an electric circuit breaker and, more particularly, to a closing control scheme which is particularly suited for high speed automatic reclosing of the circuit breaker.

A basic requirement of a closing control scheme for a circuit breaker is that it be pump-free. In other words, only one closing operation of the circuit breaker should result from eachclosing operation of a manually-operated closure-initiating device, even though the circuit breaker trips open while the initiating device is being held in a closed position. To satisfy this requirement, it has been common to rely upon a control scheme of the so-called X-Y type. In this type of scheme, a manually-operated control switch is closed to complete an energizing circuit for the usual closing, or X, device, which responds by producing closing of the breaker. At the end of the closing stroke, a cut-olf, or Y, relay is automatically caused to change its operative position thereby to open the circuit for the closing device and is maintained in its new position to prevent the closing device from being again operated so long as the control switch is held closed.

Anothervbasic requirement of a circuit breaker control scheme is that it should be capable of preventing pumping in the event that control power is lost or has its voltage reduced for some reason directly and regularly related to the circuit breaker closing operation. For example, if control power is obtained from the primary power system and has its voltage reduced when the circuit breaker is closed against a fault, the control scheme should still be capable of preventing pumping. The standard X-Y scheme is not capable of consistently meeting this requirement because without adequate control power at the end of the closing stroke, the cut-oif or Y relay is not capable of preventing pumping. This is the case because the usual Y relay acts to block reenergization of the X or closing device only when in its energized position. Without control power, the Y relay is obviously unable to remain in its energized, pumpdpreventing position.

To overcome this problem, it has been customary in appropriate situations to rely upon a type of X-Y control scheme which utilizes a cut-off relay of the reverse Y type. By this is meant a cut-ofi relay which is normally energized and picked up but which is automatically deenergized and dropped out at the end of the breaker closing stroke to achieve the desired deenergization of the closing device. Typically, in this type of X-Y scheme the reverse Y relay is maintained dropped-out at the end of a closing stroke so long as the control switch is held closed, and in its dropped-out position acts to maintain deenergization of the closing device and, in this way, to prevent pumping. Whether drop-out of the reverse Y relay at the end of the closing stroke results from normal operation ofthe control scheme or from a loss of control power is immaterial to the proper operation of this type of scheme, and, therefore, such scheme operates successfully to prevent pumping even if control power is lost at the end of the closing stroke. An X-Y control scheme ern- Patented Jan. 12, 1960 ploying such a reverse Y relay will hereinafter be termed a reverse X-Y scheme.

Prior reverse X-Y schemes have not readily lent them selves to high speed automatic reclosing duty, e.g., that duty which involves reversing the opening movement of the circuit breaker immediately after circuit interruption and before the breaker reaches fully open position. With prior schemes, because the Y relay had been deenergized at the end of a closing stroke and had been maintained in its deenergized position, it was necessary in order to reclose the breaker, rst, to pick up the Y relay, which thereupon operated to pick up the closing device. The time required for picking up the Y relay has unduly prolonged the overall period required for reclosing the breaker.

An object of my invention is to provide, for a circuit breaker, a closing control scheme of the reverse X-Y type which is capable of producing high speed automatic reclosure.

Another object is to achieve such high speed automatic reclosnre with a reverse X-Y scheme without the necessity of lirst picking-up the usual cut-off relay during the reclosing operation.

In carrying out my invention in one form, I provide, in a reverse X-Y closing control scheme, a cut-oit relay which is normally energized and in an operated positio-n but which at the end of a circuit breaker closing stroke is dropped-out to open cut-oli contacts that act to interrupt the energizing circuit for a conventional closing-control device. The cut-off relay is maintained in its dropped-out position so long as the usual manually-operated control switch is held closed and, in this way, acts through its open cut-off contacts to prevent reenergization of the closing-co-ntrol device so long as the control switch is held closed. Assuming that the breaker is in closed position, my circuit, instead of allowing the cut-off relay to remain deenergized, energizes and returns the cut-oft` relay to its operated position when the control switch is released. This closes the cut-olf contacts, but so long as the breaker remains closed, it is not possible to energize the closing device because a then open-auxiliary switch is connected in series with the closing device. To provide for high speed automatic reclosing, an early-reclosing switch is arranged to be closed in response to partial circuit-breaker opening. Upon closure, this switch completes an energizing circuit for the closing device through the then-closed cut-off contacts of the cut-olf relay. This energizing circuit can be immediately completed without the need for rst picking-up the cut-off relay to close the cut-off contacts, as in prior schemes, inasmuch as this relay had previously been picked up before the breaker began opening. Thus, the time interval required for reclosing is appreciably shortened.

For a better understanding of my invention, reference may be had to the following description taken in conjunction with the accompanying drawings wherein:

Fig. 1 is -a schematic illustration of a pneumaticallyoperated circuit breaker utilizing a control scheme embodying my invention. ln Fig. l the circuit breaker is shown in its open position. v

Fig. 2 illustrates the control scheme of Fig. 1 during the time the circuit breaker is in the closed position.

Fig. 3 illustrates a modiiied closing control scheme embodying my invention. The breaker is assumed to be in its open position.

Referring now to Fig. 1, the circuit breaker shown therein is a three-pole type of breaker comprising three sets of movable main contacts 1 adapted to cooperate with three sets of stationary contacts 2, respectively connected in the individual phases 3, 4 and 5 of a three-phase alternating power system. The main contacts 1 are APatent No. 2,479,315, Coggeshall, assigned to the assignee of the present invention. Since the details of this mechanism form no part of my invention, only those features of the mechanism deemed necessary to an understanding of my invention will be described in the present application.

This operating mechanism 6 comprises an output crank 7 and a pivotally-mounted cam lever 8. The crank 7 is mounted on a stationary pivot 9 and is pivotally connected at 10 to a contact operating rod 11, indicated schematically in part by the dash-dot line 11. This contact operating rod 11 is connected at its upper end to the movable contacts 1.

lFor actuating the crank 7 in a clockwise direction to drive the contacts 1 downwardly into closed position, the cam lever 8 is pivotally mounted on a stationary pivot 12 and is provided at its free end with a cam 13. The cam 13 is adapted to engage a roller 14 mounted on the free endof the output crank. When the cam lever 8 is driven v upwardly from its position of Fig. 1 (by means soon to be described), the camsurface 13 coacts with the roller 14 to drive the output crank'7 in a clockwise closing direction with the force and speed required for proper circuitbreaker closing. Atthe end of the closing stroke, a suitable trip latch f15 falls in behind a roller 16 mounted on the cam lever 8 and, thus, acts through the cam lever 8 and output crank 7 to hold the contacts 1 in closed position. This latching relationship is shown in Fig. 2 where the breaker is shown in its closed position.

The trip latch 15 is secured to a rotatable shaft 20 and is biased toward its latching position by means of a suitable tension spring 21. Also secured to this shaft 2t) is a latch-controlling crank 22 adapted to cooperate with a suitable electromagnetic tripping device24. in the disclosed circuit breaker, this tripping device 24 comprises a tripping solenoid which is arranged to trip the breaker in response to an overcurrent condition in the phase conductor 5 of the primary power system. In this regard, a current transformer 25 is inductively coupled to the conductor 5 and acts to supply current to an over-current relay 26 dependent upon the current in the line V5. In response to predetermined overcurrent conditions in the line 5, the relay 26 operates to complete an energizing circuit 27 for the tripping solenoid, whereupon the solenoid armature is driven to the left to trip the latch 15. Tripping of the latch 15 allows the opening spring i9 to drive the contacts into the open circuit position of Fig. l.

For driving the cam lever 8 clockwise to eiect the above-described circuit-breaker closing action, a fluid motor 30 is provided. This fluid motor 3@ comprises a pressure-confining.cylinder 31 and a piston 32 slidably mounted for vertical motion therein. The piston 32 carries a piston rod 34 having its upper end disposed immediately beneath the roller 16 on the cam lever. When pressurized fluid is admitted into the cylinder 31 beneath the piston 32, the piston 32 is driven upwardly at high speed, thereby rapidly driving the cam lever 8 clockwise to effect the desired closing action. After the latch 15 has moved into position beneath the roller 16 to'hold the breakervclosed, the piston 32 is quickly returned toits lower position in a conventional manner by means in-v cludinga compression spring 36 disposed above the piston.

The pressure of the liuid beneath the piston is controlled by means including a suitable control valve en preferably of the type shown in U.S. Patent No. 2,381,336, Coggeshall, assigned to theassignee of the present invention. Since this valve-Wis of a conventional form, it is shown in schematic form only. Referring to Fig. l, the control valve comprises an actuating electromagnet 42 which upon energization lifts its Valve element 43 to an open position, allowing pressurized iluid to flow from a pressurized storage tank 14, through the valve 4l) into the cylinder space beneath the piston 32. The piston 32 thereupon moves upwardly at high speed through its closing stroke. yWhen the piston 32 reaches the end of its upward closing stroke, it operates an a-a auxiliary switch 45 which acts (in a manner soon to be described) to effect interruption of the energizing circuit for the actuating electromagnet 42 vof the control valve. This causes the valve element A4113 to return to its closed position under the iniluence of suitable biasing means, schematically shown as the spring 47.

4In its closed position, the valve element 43 Avents the space beneath the piston 32 to atmosphere through an exhaust port 48. This causes the pressure beneath the piston 32 quickly to collapse, thus allowing the return spring 36 yquickly to drive the piston 32 to its lower and reset position. Preferably, collapse of the Huid pressure beneath the piston is accelerated by a suitable dump valve (not shown) connected in the supply line leading to the fluid motor 30. An example of such a dump valve is shown in either of the two Coggeshall patents cited hereinabove. This dump valve has been omitted in the present application for the sake of simplicity and in order to facilitate an'understanding of the present invention. Since the piston 32 is capable of quickly returning to its reset position after completion of a closing stroke, it willy be apparent that the piston will not interfere with any tripfree operation of the breaker, i.e., with any circuitbreaker opening operation which might immediately follow a closingoperation in the event that a fault is present on the power line 5 when the breaker is closed.

For controlling the above-described closing action, a closing-control circuit 5t) of the reverse X-Y type is provided.y This control circuit 60 is provided with a pair of input terminals 61 and n2 which are arranged to be supplied with rectified control power derived from the primary power circuit 3, 4, 5'. For deriving this control powerfrom the primary circuit, a suitable potential transformer 63 having its primar-y `winding 6ftconnected across the phase conductors-tl and `5 is provided. The secondary winding 65 of the potential transformer has itsoutputlterminals connected to the input terminals 61 and 62 forthe control circuit. Thus, the input terminals 61 and 62 are supplied with current dependent upon the voltage across the phase conductors 4 and 5. Normally, the average value of this primary voltage remains substantially constant and at a level sufciently high to provide adequate control voltage across the input terminals 61 and 62 to provide for proper operation of the various devices of the control circuit 6d. But a different situation may be present if the contacts 1 of the main circuit breaker should be closed when there is a fault across the phase conductors 4 and 5 on lthe load side of the contacts. For example, if 'such a between-phase fault happens to be located relatively close to the contacts 1, the primary 66tof the transformer is, in eilect, shorted out by such a fault and the voltage thereacross will be very sharply reduced until such time as the circuit breaker is opened to clear the fault. Duringthis period of reduced primary voltage, there is insufiicientcontrol voltage available to pick-up the devices of the control circuit. it is toallow for this type of situation that l have provided a type of control circuit 60 which, as will soon appear, is capable of successfully operating even though there is a loss of control power.

Connected in this control circuit 6@ is the electromagnetic actuator for the control valve 40 of the iiuid motor Sil. As shown in Fig. 1, this Vactuator i2 is connected in series with a control switch 67, which can be manually closed to complete an energizing circuit for the actuator-42 (assuming the main circuit breaker is then in open-position). This energizing circuit extends from one supply terminal 62, through the control switch 67, through a then-closed b switch 73, a set of then-closed contacts 70a, conductors 68 and 69, and the actuator 42 to the other supply terminal 61. Completion of this energizing circuit causes the actuator 42 to lift the valve element 43, thereby opening the control valve so as to allow pressurized fluid to tiow into the iluid motor and drive the piston 32 upwardly through a closing stroke.

The control circuit 60 also includes a Y or cut-off relay 70 having two sets of contacts 76a and '70h and having a coil 71 connected in series with a current-limiting resistor 72. The series combination of the coil 71 and the resistor 72 is connected across the supply terminals 61 and 62 so that, with certain exceptions soon to be pointed out, so long as normal control power is available across these terminals, the cut-off relay 7) remains in the operated position shown in Fig. 1.

The control circuit 60 also includes a b switch 73 which is controlled in accordance with the position of the circuit breaker main contacts 1. `When the main contacts 1 are in the fully open position, shown in Fig. l, the "b switch 73 is closed, but when the main contacts 1 of the circuit breaker are in closed position, the b switch 73 is in an open position. The purpose of this b switch is the conventional one of preventing useless, and possibly harmful, operations of the iiuid motor 3i) when the circuit breaker is already in a closed position. For example, refer to Fig. 2 where the circuit breaker is shown in closed position. Under such circumstances, should an unskilled operator close the manually-operated closureinitiating switch 67 the open "b switch 73 would prevent an energizing circuit -for the valve actuator 42 from being established through the control switch 67.

.For insuring that a closing operation, once initiated, is carried through to completion even though the operator might prematurely release the control switch 67, a seal-in relay 80 is provided. The coil of this relay 80 is connected in parallel with the valve actuator 42 so that whenever the actuator is picked-up, this relay S is also picked-up. T he contacts 80a of seal-in relay 80 are connected in parallel with the series-combination of the control switch 67 and the "b switch 73. As a result, opening of either or both of these latter two switches during a closing operation, when the valve actuator 42 is picked-up, is ineffective to deprive the valve actuator 42 of control power. Under such circumstances, control power is supplied to the actuator 42 through a circuit including the contacts 80a (which are then closed and bypassing the switches 67 and 73), the contacts 70a and the conductors 68 and 69.

At the end of its upward closing stroke, the piston 32 acts to close the a-a switch 46, .thus establishing a first short circuit (through switch 46) around the coil 71 of cut-01T relay 70, thereby `dropping-out the relay 70. Such drop-out causes the relay contacts 70a to open, and this interrupts the energizing circuit for the valve actuator 42. The valve 40 responds by closing, thus venting the space beneath the piston 32 through the port 48, thereby causing the piston 32 to return to its lower position shown in Fig. 2 of the drawings.

The above-described drop-out of the cut-off relay 7@ also closed its contacts 7Gb. If the operator continued holding the control switch 67 closed after completion of the closing operation, this closing of these contacts 7011 would complete a second short circuit (through the control switch 67) around the coil 71 of the cut-oit relay 70. Thus, so long as the operator holds the control switch 67 closed, the cut-oii" relay 70 is maintained dropped-out by this second short-circuit. As soon as the operator releases control switch 67, however, this second short-circuit is removed and no longer prevents the cutoft" relay 70 from again picking up.

The first short circuit (through a-a switch 46) around the coil 71 of the cut-oli relay was maintained only momentarily. In thisregard, return of the piston 32 to its lower position upon completion of the above-described closing stroke allowed the a-a switch 46 to open, and this removed the first short-circuit from around the coil 71 of the relay 7h. If the control switch 67 had previously been released, removal of this rst short circuit (through switch 46) would allow the cut-off relay 70 to be again picked up by power supplied through the coil 71 and the resistor 72.

The above-described opening of cut-off contacts 70a upon drop-out of the relay 70 at the end of the closing stroke also dropped-outthe seal-in relay 80, causing its contacts a to be opened. With contacts 80a open, the above-described reclosing of the cut-oli contacts 70a is not eiiective to complete an energizing circuit for the valve actuator 42. Thus, assuming a normal circuit breaker closing operation, i.e., one which is not immediately followed by a tripping-open operation, the cut-ofi relay 70 would pick-up to close its contacts 70a upon release of the control switch 67 after completion of the closing stroke, and the various devices will occupy the position shown in Fig. 2.

As was previously pointed out, a basic requirement of a circuit breaker control scheme is that it be pump-free. To satisfy this requirement, only one closing operation of the breaker should result from each closing of the control switch 67, even though the circuit breaker trip opens While the control switch 67 is being held in the closed position. To illustrate the manner in which my control scheme meets this requirement, assume that the previously-described closing action takes place when a fault happens to be present on the primary power circuit, say, from conductor 5 to ground. Assume, also that the operator continues holding the closing-control switch 67 closed after completion of the breaker-closing operation. Under such conditions, as soon as the main contacts 2 of the circuit breaker reach closed position, fault current would begin flowing through the conductor 5, thus picking-up the overcurrent relay 26 and thereby causing the solenoid 24 to trip the trip latch 15. When the latch 1S is thus tripped, the opening spring 19 will rapidly drive the movable contacts 1 through their opening stroke. The piston 32 will not interfere with such opening movement since it has been driven back into its lower position by its reset spring 36 well ahead of the links 7 and 8 of the operating mechanism.

Since the control switch 67 is assumed to be held closed, the cut-01T relay 70, after having dropped out at the end of the closing stroke, would remain dropped-out due to the short circuit around its coil through its contacts 70b and the control switch 67. The contacts 7Go of the cut-oif relay would thus remain open and prevent an energizing circuit from being established for the valve actuator 42. Had these contacts 70a not been open, closing of the b switch 73 in response to opening of the circuit breaker would have completed an energizing circuit for the valve actuator 42, thus causing another operation of the fluid motor (which would be a pumping condition that the present circuit prevents). Thus, by maintaining the cut-off relay 70 dropped-out, it is possible with the present circuit to hold the control switch 67 closed without causing repetitive circuit breaker closures, even though the breaker is tripped open while the control switch 67 remains closed. In other words, pumping is prevented.

A second basic requirement for many circuit breaker control schemes is that it should be able to prevent pumping even in the event that control power' is lost. For example, in the present circuit, assume that contacts 1 of the breaker are operated to closed position when there is a fault across the phase conductors 4, 5 located on the load side of the breaker relatively close to the breaker. The primary 64 of the control power transformer is, in effect, shorted out by such a fault and, accordingly, the voltage thereacross will be sharply reduced or, in effect,

lost. This does not interfere with the ability of my circuit 60 to prevent pumping because at the end of the closing stroke my cut-off relay 70 is normally droppedout anyway, irrespective of Whether control power is present across the circuit terminals 61, 62. Thus, if control power is lost and the operator continues holding the control switch 67 closed after the closing operation, the cut-off relay 70 simply remains dropped-out. When control power becomes again available, e.g. after the circuit breaker has tripped to clear the fault, the contacts 7tlb of the cut-off relay are still closed, thus preserving the short circuit 67, '70b around the coil 7l of the cut-oft relay, thereby preventing its pick-up until the control switch 67 is released. As previously pointed out, so long as the cut-off relay 70 is dropped-out, its contacts '7tlg are open and thus act to prevent reenergization of the valve actuator 42. Thus, even though there .has been a loss of control power, the control switch 67 must be lirst released before it can act to initiate another closing operation.

My control circuit 60 readily lends itselfto high-speed automatic reclosing duty. For example, assume that the breaker has been tripped toward openposition from its normal closed position of Fig. 2 ,and that itis desired to `reclose the breaker immediately after circuit interruption by reversing the opening motion of the .breaker before the fully open position is reached. For this purpose, I provide a reclosing control circuit 81 shunting the series combination of the closing control switch 67 and thefb contacts 73. This reclosing control circuit 81 includes an early-reclosing switch 82 controlled in accordance with the position of the circuit breaker main contacts l and preferably mechanically coupled to the b switch 73. This switch 82 is open when the breaker is closed but is closed in response to a partial opening stroke of the movable contacts l. Also in the reclosing control circuit and connected in series with the earlyreclosing switch 82 is a reclosing-selection switch 84 which is normally open to disable the reclosing control circuit. When the breaker is in closed position and it is desired to set the breaker for automatic reclosing, this selection switch 84 is closed, as shown in Pig. 2. 'A suitable lock-out device 85 of conventional form is also connected in the reclosing control circuit81 for the purpose of allowing, preferably, only a single automatic reclosure.

The switch 84 and the lock-out device 85 can, if desired,

be replaced by a conventional reclosing relay which provides for lock-out in a corresponding manner.

Assume now that the selection switch 84 is in closed position and that the circuit breaker is tripped from its normal closed position of Fig. 2. A partial opening movement of the main contacts 1 closes the early-reclosing switch 83, thus immediately completing an energizing circuit for the valve actuator 42. The valve actuator responds by opening the valve 40, thus initiating upward movement of the piston 32 well before the main contacts l can be moved through their full opening stroke.

It will be apparent from the above-description that the disclosed circuit 60 enables the early-reclosing switch 82 to directly initiate operation of the valve actuator 42. It is not necessary, as in prior circuits, to rst pick-up another relay (such as a dropped-out cut-olf relay) which, in turn, produces operation of the actuator. By eliminating this latter requirement, the disclosed circuit can eliminate the time delay required to pick-up such intermediate devices, thus materially shortening the time interval required for reclosing.

The disclosed control circuit also acts to prevent pumping after an automatic reclosing. For example, if for any reason the early reclosing switch 32 should become stuck or otherwise held in closed position, the circuit 6l? would operate to prevent a second automatic reclosure `in essentially the same manner as it acts to prevent pumping after a kmanually-initiated closing. In this rregard, if the early-reclosing switch 82 should, ,forsome reason, ybe held in closed position, the b switch 73 which is mechanically coupled to the early-.reclosing switch 82 would also be held in closed position. Assuming such a condition, at the end of the reclosing stroke the tt-a switch 46 would close to effect drop-out of the cut-orf relay 70, which in turn would open its contacts Illia and thus interrupt the energizing circuit for the valve actuator 42. The relay 70 would remain dropped-out so long as the switches 82 and 73 remained held closed because, under such conditions, the coil of the cut-olf relay 70 would be shorted-out by a circuit extending through the reclosing control circuit 81, through the then-closed b switch 73, and through the then-closed contacts llib'of the cut-off relay. With'the cut-olf relay maintained dropped-out in this manner,.its contacts jtm are open, thus preventing re-energization of the valve actuator 42 .until the early-reclosing switch 82 or the reclosure-selection switch S4 is rst opened.

From the description of the preceding paragraph, it will be apparent that the contacts 70a of the cut-olf relay 7l) serve important purposes during an automatic reclosing operation. lt is therefore important that any energizing circuit for the valve actuator 42 extend through these contacts 70a.

Fig. 3 illustrates a modified closing control circuit embodying my invention, with those parts corresponding to similar parts of Fig. l assigned corresponding reference numerals. lt is to be understood that identical-designated devices are controlled from the circuit breaker in the same manner in Fig. 3 as in Fig. l. Anti-pump characteristics are obtained in the scheme of Fig. 3 in a somewhat different manner from that of Fig. 1. In this regard, the manually-operated control switch 67a of Fig. 3 has been provided with an extra'set of contacts 67b which are normally closed. When the normally-open contacts 67a are operated to closed position to initiate a closing operation, contacts 67b are opened. Energizationrof the cut-olf relay '70 thereafter takes place through a set of seal-in contacts 7Go provided on the cut-olf relay 7th and connected in parallel with the contacts 67b. Closing of the contacts 67a completes an energizing circuit for the valve actuator 42 which produces a closing operation of the breaker in the same manner as described in connection with Fig. l.

At the end of the closing stroke, the a--a switch 46 is closed to drop-out the cut-off relay 70. This opens the cut-off contacts 70a to effect deenergization of the actuator 42 in the same manner as pointed out in Fig. 1. Drop-out of the cut-off relay 7l) also opens its contacts tlc so that subsequent opening of a-a switch 46 is not effective to produce re-energization of the cut-olf relay "/"tl so long as contacts 67b remain open. Thus, if the operator holds the control switch 67a, 67b in its operated position, the open contacts 67 b act to prevent reenergization of the cut-olf relay 70.

By maintaining the cut-olf relay dropped-out so long as the control switch is held in its operated position, cut-olf contacts 70a are held open and re-energization of the valve actuation 42 is thus prevented. As a result, pumping is prevented in the samev manner as in the scheme of Fig. l. When the control switch is released, its contacts 67b close, thus completing an energizing circuit for the cut-off relay 70. Relay 70 responds by picking-up and closing its contacts 70a, so that the valve actuator 42 can again be energized through contacts 70a when the breaker is subsequently opened.

lf the control switch 67a, 67b were released before the closing stroke `were completed, seal-in relay 80, with its then-closed contacts a shunting the control switch, would assure completion of the closing stroke in the same manner as in Fig. l. At the end of closing stroke, the cut-olf contacts 76a wouldk open to interrupt the energizing circuit for the'valve actuator 42 and" the seal-in relay 80. Drop-out of the seal-in relay 80 would open its contacts 80a to open the seal-in circuit. Assuming the breaker then to be closed, the various devices would occupy the positions illustrated. in Fig. 1 except for b switch 73 and the early reclosing switch 82 both of which would then be in open position.

The control scheme of Fig. 3 could then be set for a rapid automatic reclosing merely by closing the reclosure-selection switch 84. Thereafter, when the breaker tripped open, the early-reclosing switch 82 would close to produce immediate energization of the valve actuator 42 and resulting reclosing in the same general manner as described in connection with Fig. 1.

While I have shown and described a particular embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects and I, therefore, intend in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a closing control circuit for a circuit breaker, terminals for supplying control power to said circuit, an electro-responsive closing-control device having an actuating part connected in said circuit and operable upon energization of said actuating part to initiate a breakerclosing stroke, a manually-controlled switch connected in series with said actuating part and closable to complete an energizing circuit therefor so as to initiate a breakerclosing stroke, a cut-off relay having connected in series with said actuating part a set of cut-oif contacts that are closed when said cut-off relay is in operated position, means for maintaining said cut-off relay in an operated position at all times that control power is available except momentarily at the end of a circuit breaker closing stroke and except when said manually-controlled switch is held closed after completion of a circuit breaker closing stroke, means responsive to a circuit breaker closing operation for dropping-out said cut-ot relay at the end of said closing stroke thereby to open said cut-off contacts and effect deenergization of said actuating part, anti-pump contact means operative after drop out of said cut-oi relay to maintain said cut-off relay dropped out so long as said manually-controlled switch is held closed, means operative when said circuit breaker is closed for again producing operation of said cut-off relay immediately after drop-out thereof assuming said manually-controlled switch is not then being held closed, and reclosure-initiating switch means connected in parallel with said manually-controlled closing switch and in series with said actuating part and with said cut-oit contacts, and means responsive to opening movement of said circuit breaker for closing said reclosure-initiating switch means prior to completion of a circuit breaker opening stroke thereby to initiate a rapid reclosing operation.

2. In a closing control circuit for a circuit breaker, terminals for supplying control power to said circuit, an electroresponsive closing-control device having an actuating part connected in said circuit and operable upon energization of said actuating part to initiate a breaker-closing stroke, a manually-controlled switch connected in series with said actuating part and closable to complete an energizing circuit ltherefor so as to initiate a breaker-closing stroke, a cut-ott relay having connected in series with said actuating part a set of cut-off contacts that are closed when said cut-off relay is in operated position, means for maintaining said cut-off relay in an operated position at all rtimes that control power is avail- Iable except momentarily .at the end of a circuit breaker closing stroke and except when said manually-controlled switch is held closed after completion of a circuit breaker closing stroke, means responsive to a circuit breaker closing operation for dropping-out said cut-off relay at the end of said closing stroke thereby to open said cut-off contacts and effect deenergization of said actuating part, antipump contact means operative after drop out of said cut-oit relay to maintain said cut-oit relay dropped out so long as said manually-controlled switch is held closed, means operative when said circuit breaker is closed for again producing operation of said cut-off relay immediately after drop-out thereof assuming said manuallycontrolled switch is not then being held closed, auxiliary switch means connected in series with said actuating part, means sensitive to the operative position of said breaker for closing said auxiliary switch means when the breaker is open and for opening said auxiliary switch means when the breaker is closed whereby to maintain said actuating part deenergized when the breaker is in closed position, seal-in means responsive to completion of said energizing circuit for said actuating part for rendering opening of said auxiliary switch means inoperative to deenergize said actuating part during a closing stroke, and reclosureinitiating switch means connected in parallel with said auxiliary switch means and said manually-controlled closing switch and in series with said actuating part and with said cut-off contacts, and means responsive to opening movement of said circuit breaker for closing said reolosure-initiating switch means prior to completion of a circuit-breaker opening stroke thereby to initiate a rapid reclosing operation.

3. In a closing control circuit for a circuit breaker, terminals for supplying control power yto said circuit, an electroresponsive closing-control device having an actuating part connected in said circuit and operable upon energization of `said actuating part to initiate a circuit breaker closing stroke, a cut-ofi relay having connected in series with said actuating part cut-off contacts closable upon operation of said relay, means for maintaining said cut ot relay in an operated position whenever said breaker is open and control power is available, a manually-controlled switch closable to complete an energizing circuit for said actuating part through said cut-off contacts thereby to initiate a breaker-closing stroke, means for dropping out said cut-oif relay momentarily at the end of said closing stroke whereby said contacts are opened to effect deenergization to said actuating part, means etfective when said breaker is closed and control power is available for again producing operation of said cut-off relay when said manually-controlled switch is opened, auxiliary switch means closed when the breaker is open and opened by circuit breaker closing movement for maintaining said actuating part deenergized when the breaker is closed, seal-in means responsive to completion of said energizing circuit for said actuating part for rendering opening of said auxiliary switch means inoperative to deenergize said actuating part during a closing stroke, and reclosure-initiating switch means connected in parallel with said auxiliary switch means and said manually-controlled closing switch and in series with said actuating part and with said cut-off contacts, and means responsive to opening movement of said circuit breaker for closing said reclosure-initiating switch means prior to completion of a circuit breaker opening stroke thereby to initiate a rapid reclosing operation.

4. In a closing control circuit for a circuit breaker, terminals for supplying control power to said circuit, an electroresponsive closing-control device having an actuating part connected in said circuit and operable upon energization of said actuating part to initiate a breakerclosing stroke, a manually-controlled switch connected in series with said actuating part and closable to complete an energiizng circuit therefor so as to initiate a breaker closing stroke, a out-0E relay haiving connected in series with said actuating part a set of cut-off contacts that are closed when said cut-off relay is in operated position, means for maintaining said cut-off relay in an operated position at all times that control power is available except momentarily at the end of a circuit breaker 11 closing stroke andtexcept when said manually-controlled -switch is .held closed after completion of a. circuit breaker closing stroke, means responsive to a circuit breaker closing operation for dropping-out said cutoff relay `at the end of said closing stroke thereby to open said cut-off contacts and elect dee-nergization of said actuating part, anti-pump Contact means operative after drop out of said cut-o relay `to maintain said cut-o relay dropped out so long sas said manually-controlled switch is held closed, means operative when said circuit breaker is closed for again producing operation `of said cut-off relay immediately afterdrop-out thereof assuming said manually con-V trolled switch is not then beingl held closed, auxiliary switch means connected in series with said actuating part and sensitive to the operative position of said breaker for maintaining said actuating part deenergized when thebreaker is in closed position, seal-in means responsive to completion of said energizing circuit for for .closing said .reclosure-initiating switchmeans prior tocornp-letion ofva circuit breaker opening stroke therebyto'. initiate a rapid reclosing operation.

5. The closing control circuit of claim 4 in which said cut-ofi' relay comprises an operating coil and in which said anti-pump contact means comprises a set of contacts which are closed in response to drop-out of said cut-01T relay, said set of contacts being connected in series with said manually-controlled switch and acting when closed to short circuit the operating coil of said cavoli relay so long as said manually-controlled switch ishel-d closed. Y

6. Theclosing control circuit of claim 4 in which said cutoi relay comprises an operating coil and in which said anti-pump .Contact meanscomprises a set of normally-closed contacts provided onv said manually-- controlled switch and opened by closure of said manually-controlled switch, said normally-closed contacts being connected in series with said operating coil lof said cut-off relay, said cut-off relay also comprising a set of seal-in contacts connected iu series with said coil and in parallel with said normally-closed contacts.

No references cited.

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