US2562485A - Control and indicating system for circuit breakers - Google Patents

Description

W. F. CRUESS July 31, 1951 CONTROL AND INDICATING SYSTEM FOR CIRCUIT BREAKERS 2 Sheets-Sheet 1 Filed April 29, 1949 cm R a I Y m 4. E C W V 1 T m m M wg @M ow Mm .flnl: 6 3 mm -L I 50w mm n c E \DOQ O 9 llll. E mm 0w HO E W July 31, 1951 w. F. CRUESS 2,562,485

CONTROL AND INDICATING SYSTEM FOR CIRCUIT BREAKERS Filed April 29, 1949 sheets s et 2 INVENTOR Willia Gauss.

ATT 9p EY Patented July 31, 1951 c'oNrrRoL AND INDIOATING SYSTEM FOR omoorr BREAKERS William F. Cruess, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application April 29, 1949, Serial No. 90,461

11 Claims. 1

My invention relates generally to control systems for circuit breakers, and it has reference in particular to remote control systems for circuit breakers.

Generally stated, it is an object of my invention to provide a remote control system for a circuit breaker which is simple and inexpensive to manufacture, and is reliable and effective in operation.

More specifically, it is an object of my invention to provide, in a remote control systenrfor a circuit breaker, for preventing false operation of the breaker as a result of a fault on the signal channel between the control station and the remote breaker location.

Another object of my invention is to provide, in a remote control system for a circuit breaker, for normally disconnecting the breaker control relays from the signal channel to prevent false operations,

Yet another object of my invention is to provide, in a remote control system for a circuit breaker, for normally connecting the signal channel to the battery at the remote breaker location, and for disconnecting the breaker control equipment from the signal channel so as to prevent false operation of the breaker as a result of a short-circuit or open-circuit of the signal channel.

It is also an object of my invention to provide, in a direct wire remote control system for a circuit breaker, employing but a single pair of conductors, for obtaining a synchronizing indication when closing the breaker.

Another important object of my invention is to provide, in a direct wire remote control system for a circuit breaker, .for normally applying a line supervision potential to the signal channel from the remote breaker location, which potential will be effective to render the breaker control equipment ineffective, and for applying a control potential to the signal channel from the control station to render the breaker control equipment effective to perform an operation of the breaker.

I also propose to utilize in a direct wire remote control system for a circuit breaker, oppositely polarized breaker control relays and positionindicating relays, which are selectively connected to and disconnected from the signal channel de-' pending on whether the channel is energized from the control station or the, remote breaker location.

Itis also an important object of my invention to provide, in a remote control system for a circuit breaker, for attaining the hereinbeforerecited objects with but a single pair of conductors.

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

In practicing my invention in one of its forms, a circuit breaker at a remote breaker location is controlled from a control station over a direct wire signal channel, comprising a single pair of conductors, by means of polarized breaker control relays. The signal channel is normally energized from the remote breaker location, with the polarity dependent on the operating position of the circuit breaker and a transfer relay responsive to such energization normally disconnects the breaker control relays from the channel. Polarized indicating relays at the control station are responsive to the signal channel polarity. A circuit breaker control switch at the control station disconnects the indicating relays from the channel and applies a control potential thereto for effecting operation of the breaker control relays. Line supervision is obtained by means of a line supervision relay which is responsive to simultaneous deenergization of the position indicating relays.

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

Fig. l is a diagrammatic view of a remote control system for a circuit breaker embodying the invention in one of its forms; and

Fig. 2 is a diagrammatic view of a remote control system for a circuit breaker embodying'the invention in a different form.

Referring to Fig. 1, the reference numeral Ill may denote, generally, a remote control system for controlling a circuit breaker [2 at a remote location 13 from a control station M, which may be connected to the remote breaker location by means of a direct wire signal channel comprising line conductors l5 and l6.

The circuit breaker I2 may be of any suitable type comprising, for example, main contact members IZA and IZB disposed to connect power conductors 16a, I62) and Ila, l'lb, respectively; The breaker I2 may be provided with an operating winding 19 for actuating an armature 20'operatively connected to the contact members 12A and I213. Control of the circuit breaker l2 may be obtained by means of suitable control relays such as a closing relay 22 having an operating winding 23, and a cut-off relay 25 having an operating winding 26. The breaker l2 may also' be provided with a latch device 28 having a trip winding 29 which may be energized to release the breaker. The usual manual control means may be provided for the breaker, being represented by the close and trip push button switches 30 and 32 respectively.

In order to provide for remotely controlling the circuit breaker [2, close and trip breaker control relays 34 and 35 may be provided having operating windings 36 and 31, respectively. The control relays 34 and 35 may be polarized in opposite directions by means of rectifier devices 39 and 40 which connect the operating windings 36 and 31 to the line conductor I5, so as to make them selectively responsive to different polarities applied to the signal channel.

In order to prevent false operation of the circuit breaker, means such as a transfer relay 42 may be provided for normally disconnecting the breaker control relays 34 and 35 from the signal channel. The transfer relay 42 may be provided with an operating winding 44, which may be normally energized through a control circuit provided by a transfer control relay 45 having an operating winding 48. The transfer control relay 45 may be of the delayedoperation type, having a capacitor 43 connected in shunt relation with its operating winding 46.

At the control station [4, closed and open circuit breaker position indicating relays 41 and 48, having operating windings 49 and 50, may be provided for indicating the operating position of the circuit breaker I 2 by providing energizing circuits for red and green indicating lamps R and G, respectively. The relays 41 and 48 may be polarized in opposite directions by means of rectifier devices and 52 so as to be selectively responsive to the polarity of the signal channel.

A breaker position indicating control relay 55 may be provided at the remote breaker location having an operating winding 56 energized when the breaker I2 is closed so as to provide for changing or reversing the polarity of the signal channel in accordance with the position of the breaker. A line supervision relay 51 having an operating winding 58 may be provided at the control station for controlling an alarm 59.

Control means such as a circuit breaker control switch 60 may be provided at the control station 14 for obtaining remote operation of the circuit breaker. The control switch 60 may be of any suitable type, and for purposes of illustration is shown as a drum type switch, which normally connects the position indicating relays 41 and 48 to the signal channel in its intermediate or off position. In its trip and close posi tions the switch 60 disconnects the position indicating relays from the signal channel and reverses the polarity of the line conductors l5 and 16 for obtaining the desired operation of the breaker. Adjustable balancing resistors 53 and 54 may be provided in connection with the line conductor I8 for compensating for differences in battery potentials and balancing the line conductor resistance, respectively.

With the circuit breaker [2 in the open position, the position indicating control relay 55 will be deenergized, so that line conductor I5 is connected to the negative terminal of the battery at the remote breaker location through contact member 55a, and conductor I6 is connected to the positive terminal through contact member 550. The transfer control relay 45 will have been energized initially, through contact members 420 of the transfer relay 42.

This results in the transfer relay 42 being ener gized and closed, since its operating winding 44 will be connected between the conductors i5 and I6 through a circuit extending from conductor l5, through conductor 6|, operating windin 44, contact members 45a of the transfer control relay 45, contact members 34a, contact members 35a, and conductor Hi, to positive through contact members 550.

The transfer relay 42 provides a holding circuit for itself through its contact members 42b, resistor 54 and contact members 42d, and disconnects the breaker control relays 34 and 35 from the signal channel at contact members 42a. It also connects the channel to the remote location battery through contact members 42d, and interrupts the energizing circuit of transfer control relay 45 at contact members 420.

At the control station, position indicating relay 48 will be energized over a circuit extending from conductor [6, through conductor 62, contact members 60a of the breaker control switch, conductor 63, operating winding 50, and rectifier device 52 to conductor I5. Position indicating relay 48 provides an energizing circuit for the green light G, through contact members 485, and interrupts the energizing circuit for the line supervision relay 5! at contact members 48a.

To close the circuit breaker l2, the operator moves the breaker control switch 60 to the "close position. The energizing circuit for the position indicating relay 48 will be interrupted at contact members 60a, while the energizing circuit for the line supervision relay 51 will be in terrupted at contact members 60d. At the same time the conductor l5 will be connected to the positive terminal of the battery at the control station through contact members 60d and conductor IE will be connected to the negative terminal through contact members 60b.

The batteries at control station and remote breaker location are now connected in opposition, so that the operating winding of the transfer relay 42 will have substantially zero voltage across it, thus causing the transfer relay to return to the deenergized or open position. This provides an energizing circuit for the breaker control relay 34, extending from conductor I5 through rectifier device 39, operating winding 36, conductor 66, contact members 42a back to line conductor l6, since deenergization of the transfer relay 42 disconnected the remote breaker location battery from the signal channel at contact members 42d.

Upon operation of the breaker control relay 34 an energizing circuit is established for the closing relay 22, extending from negative through contact members l2b of the circuit breaker, operating winding 23, resistor 88, and contact members 34b to positive. The closing relay 22 operates, providing a holding circuit for itself through contact members 220, and providing an obvious energizing circuit for the operating winding IQ of the circuit breaker l2 through contact members 22a and 22b to effect closing of the breaker. Operation of the circuit breaker provides an energizing circuit for the operating winding 26 of the cut-off relay 25, through contact members [2d of the circuit breaker and contact members 22d. The operating coil of the closin relay 22 is thereupon shunted through contact members 25a of the cutoil relay, which provide a holding circuit for itself through contact members 25b.

Operation of the circuit breaker also provides an obvious energizing circuit for the operating winding 56 of the breaker position indicating control relay 55. The control relay 55 operates to the energized position and reverses the connections of the conductors l5 and Hi to the remote location battery. fhe transfer control relay 45 i energized as soon as the transfer relay s2 drops but does not operate until after a short time delay. Relay 45 then provides an energizing circuit for the transfer relay 42, as soon as the breaker control switch cs is released to drop the breaker con trol relay 3 The transfer relay t2 thereupon disconnects the breaker control relays 34 and 35 from the signal channel, and reconnects the channel to the remote location battery through contact members 42d.

At the control station, an energizing circuit will now be provided for the position indicating relay 41, extending from line conductor is through rectifier device 5|, operating winding 43, conductor 63, and contact members Gila, back to line conductor IS. The position indicating relay Al there= upon operates and pr rides an obvious energizing circuit for the red lamp R through contact members All). A trip operation may be performed by operating the control switch Gil to the trip position to pick up breaker control relay 35.

Should the line conductors l5 and it become either open-circuited or short-circuited, the par ticular position indicating relay which happens to be energized, in this instance relay will return to the deenergized position. This completes an energizing circuit for the line supervision relay 51, extendin from positive through contact members 69d of the breaker control switch, contact members 41a, contact members 46a and the operating winding 58 of the line supervision relay 51 to negative. The line supervision relay 51 operates and energizes the alarm 59.

In the event that the conductors l5 and It become open-circuited, the transfer relay 42 will remain in the energized position, in which it disconnects the breaker control relays as and 35 from the line conductors at contact members 42a. Should the line conductors become short-circuit ed, the transfer relay c2 will return to the deenerglzed position, in which it disconnects the brealo er location battery from the line conductors at contact members 42d. In both instances, false operation of the breaker control relays is efiec tively prevented.

Referring to Fig. 2, the reference numeral may denote generally a. remote control system for a circuit breaker H at a remote breaker location l3 which may be connected to a control station M by means of a signal channel comprising line conductors G5 and 66-, similar to the conductors l5 and It described in connection with Fig. 1.

Operation of the circuit breaker l2 may be effected by means of closing and cut-off relays 2 2 and 25, substantially identical with the corresponding relays shown in Fig. l. Latch means '28 having a trip windin 29 may be provided for opening the circuit breaker. lush button switches 30 and 32 may be provided for operating the breaker from the remote location. Selective op eration of the closing relay and latch means may be effected by means of circuit breaker control relays 34 and 35 which may be connected to the signal channel through oppositely disposed recti fier devices 39 and All in a manner similar to the described in connection with Fig. 1.

At the control station position indicating relays 41 and 48 may be provided in connection with associatedrectifier devices El and 52 for selective operation in response to the operating position of a breaker position indicating control relay 55 at the remote breaker location.

Instead of utilizing a transfer relay such as the relay A2 of Fig. 1, a transfer relay ll may be provided, having an operating winding '12 which is disposed to be connected in series circuit relation with the signal channel conductors 65 and 66 and the operating winding of whichever or the position indicating relays 41 and 48 may be energized. A transfer control relay 45, having a hunt capacitor 43 for effecting delayed operation thereof, may be provided for effecting energization of the transfer relay ll' initially, in a manner similar to that described in connection with the operation of the relays 45 and 42 in connection with Fig. l of the drawings.

In order to permit synchronizing the connection of the conductors 15a, Ila, i522, i'ib, means such as a synchronizing transmitter may be provided. The transmitter 15 may be of a type well known in the art comprising, for example a rectifier bridge circuit it which may be ener gized with the differential voltage obtained from control transformers ll and it, which may be connected to the conductors Isa, Ila, 1612, Ho. A synchronizing control relay til having an opcrating winding 3! may be utilized for connecting the transformers ll and 15 to the conductors 110;, 1th, ill and applying the diiierential voltage, if any, to the line conductors 35 and so. An auxiliary control relay 82 having a rectifier device 33 connected in circuit relation with its operating winding 84, may be provided for effecting operation of the synchronizing control relay ill). A time delay relay 85 having an op erating winding 85 may be provided for deener gizing the auxiliary control relay 82 to complete the connection of the transmitter 75 to the signal channel.

At the control station is a synchronizing receiver 8'! may be provided for connection to the line conductors [55 and 88 to register the differential voltage produced by the transmitter To. A synchronizing switch 88 may be provided in connection with the synchronizing receiver 81 for applying a positive potentialto the line conductor 55 and effecting operation of the control relays 3t and 8.2, and at the same time disconnecting both the synchronizing receiver 8'! and the position indicating relays 41 and do from the signal channel.

A synchronizing indicating relay as having an operating Winding 39, may be provided for connecting the receiver 87 to the signal channel and disconnecting the position indicating relays Ill and 38 therefrom during a synchronizing operation. The synchronizing indicating relay 89 also provides an energizing circuit for a white synchronizing lamp W. At the remote breaker location an auxiliary breaker control relay 92 may be provided, having an operating winding 93 connected in circuit relation with the synchronizing transmitter 15 and the channel con doctors 55 and 66. A shunt resistor 94 may be provided in connection with the transmitter 75 to permit operation of the auxiliary relay $52 to disconnect the transmitter from the channel in response to a breaker closing potential applied to the signal channel from the control station.

When the circuit breaker 12 is open, the breaker position control relay 55 will be in the deenergized position. An obvious energizing circuit for the transfer control relay 45 is provided through con= tact member lie. Relay '45 operates and completes an energizing circuit for the line transfer relay l; through contact member 45a. The line conductors 65 and 65 will be connected to the battery at the remote breaker location over a circuit extending from positive through contact members 55a, operating winding [2 of the line transfer relay ll, contact members Ha, conductor 36, contact members Bila of the synchronizing transmitter control relay 8%, line conductor 65, rectifier device 52, operating winding 50 of the position indicating relay 48, contact members 89a, contact members 88a, contact members 60a, conductor 66, and contact members 'Hb to negative through contact members 551).

Accordingly, both the transfer relay II and the trip position indicating relay 48 will be in the operated position. Relay 48 provides an obvious energizing circuit for the green light G to indicate that the breaker is in the open position.

Before closing the circuit breaker l2, the operator depresses the synchronizing switch 88, which momentarily interrupts the series circuit through the operating windings of the relays TI and 48 at contact members 88a. It also applies potential to the line conductors 65 and 66 from the control station battery at contact members 380 and 88b, respectively, and energizes the synchronizing indication relay 89 through contact members 88d. Accordingly, the synchronizing indication relay 89 operates, and provides a hold ing circuit through contact members 89d, connecting the receiver 8! to the signal channel through contact members 8% when the switch 88 is released.

The transfer relay ll returns to the deenergized position and disconnects the conductors 65 and 66 from the remote location battery at contact members Ha and Ho. Deenergization of transfer relay 'H completes an energizing circuit for the auxiliary control relay 82, while the switch 88 is depressed extending from the control station battery positive through contact members 880, conductor 91, line conductor 65, rectifier device 83, operating winding 34, contact members 850., contact members 'Hc, conductor 98 and conductor 99 to line conductor 66 and control station battery negative through contact members 85b.

Auxiliary control relay 82 operates, opens the synchronizing circuit at contact members 8211 and 82c, and completes an energizing circuit for the synchronizing control relay 80 through contact members 820. The control relay 80 sets up a connecting circuit for the synchronizing trans-- mitter 15 through contact members 30) and 80g, connects the transformers Ti and 18 to the power circuit through contact members 80d and 80c, and provides an energizing circuit for the time delay relay 85, which interrupts the energizing circuit for the auxiliary control relay 82 at contact members 85c, but relay 62 held energized by its holding circuit contact. Whenthesynchronizing switch 88 is released; thus removing the potential from line wires 65 and 6E, relay 82 deenergizes and completes the connecting circuit for the synchronizing transmitter 15 at contact members 82d and 826. As soon as the synchronizing switch 88 is released the synchronizing receiver 81 is connected to the signal channel to indicate the differential voltage produced by the transmitter 15, and give a synchronizin indica-' tion.

To close the breaker 12, the breaker control switch 30 may be operated to the close position, so as to connect positive battery to the line conductor 65 and negative battery to the line conductor -66 after first disconnecting the synchronizing receiver 81 through contact members 60a.

This results in operation of the auxiliary breaker control relay 92, which interrupts the energizing circuit for the synchronizing control relay 8|] at contact members 92a. Deenergization of the synchronizing control relay disconnects the synchronizing transmitter 15 at contact members 80f and 80g, and provides an energizing circuit for the circuit breaker control relays 34 and 35 through contact members 80a, conductor 96, conductor I00 and contact members Hd. Breaker control relay 34 will be energized because of the direction of its polarization and complete an energizing circuit for the closing relay 22 through contact members 34b to close the circuit breaker 42 in the manner described hereinbefore in connection with the system of Fig. 1. Breaker control relay 34 also completes a holding circuit for the time delay relay 85.

The breaker control relay 34 will remain energized until the operator releases the breaker control switch 60, whereupon its energizing circuit will be interrupted. Deenergization of the control relay 34 interrupts the energizing circuit for the time delay relay at contact members 34a, causing the time delay relay 85 to return to the deenergized position after a predetermined time. An energizing circuit is thereupon provided for the line transfer relay 1 l, extending from negative through contact members 55a, operating winding 12, contact members 45a of the auxiliary transfer relay 45, contact members 35a, contact members 82b and contact members 850 and resistor 102 to positive through contact members 552).

At the control station position indicating relay 4'! will be energized in series circuit relation with the line transfer relay H to provide an obvious energizing circuit for the red lamp R. At the breaker location the auxiliary transfer relay 45 returns to the deenergized position after a predetermined time, and interrupts the original energizing circuit for the line transfer relay H, which remains connected in series circuit relation with the position indicating relay 4'! and the signal channel.

Since the breaker control relays 34 and 35 are disconnected from the signal channel at contact members lld of the line transfer relay, neither an open-circuit nor a short-circuit on the line conductors B5 and 66 can effect operation thereof.

A trip operation of the breaker l2 may be effected by operating the breaker control switch 60 to the trip position. This disconnects the position indicating relays 4'! and 48 from the signal channel, and effects operation of the breaker control relay 35, which provides an obvious energizing circuit for the trip means 28 through contact members 35b. Tripping of the breaker deenergizes the breaker position control relay 55, and reverses the polarity of the line conductors B5 and 66. The position indicating relay 48 will thereupon be energized at the control station when the breaker control switch 60 is returned to the off position, to complete the connection of the operating winding 50 to the line conductors at contact members 60a. The green lamp G will now be lit, and the red lamp R will be extinguished, by the return of the position indicating relay 41 to the deenergized position.

Neither an open-circuit nor a short-circuit of the line conducors 65 and 66 can result in deenergization of the breaker control relays 34 and 35.

An open-circuit of the line conductors 65 and awash 9 86 will result in deenergization of the transfer relay H, thus disconnecting the breaker location battery from the breaker control relays 34 and 35 at contact members '1 la and '1 lb. A short-circuit of theline conductors 65 and 6% will allow transfer relay ll to remain energized, thus keeping the breaker control relays 34 and 35 disconnected from line conductor 65 at contact members H d.

Thus, in either case, breaker control relays 3L and 35 are disconnected from any source of potential thus preventing false operations of the breaker. I

I Either an open-circuit or a short-circuit on line conductors 65 and 66 will prevent current from the breaker location battery from reaching the control station. Both of the position indicating relays 41 and 48 will thereupon return to the deenergized position, and an obvious energizing circuit will be provided to the line supervision relay 51', which connects the alarm 59 to the control station battery.

From the above description and the accompanying drawings it will be apparent that I have provided in a simple and effective manner for controlling the operation of a remote circuit breaker over a direct wire signal channel comprising but a single pair of conductors. Continuous supervision of the signal channel isprovided, and false breaker operation is reduced to a minimum, since the breaker control relays are effectively disconnected both normally andwhen a fault occurs on the signal channel. A synchronizing indication is also provided over the direct wire signal channel for facilitating operation of the remote breaker.

Since certain changes may be made in the above described construction, and different embodiments oi 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 drawings shall be considered as illustrative and not in a limiting sense.

I claim as my invention:

1. In a remote control system for controlling a circuit breaker at a remote location from a control station over a signal channel, control means for the breaker selectively responsive to the polarity of the signal channel, switch means at the remote station operable to connect the signal channel to a direct current source at the remote location selectively in accordance with the breaker position, transfer means normally responsive toenergization of the signal channel from the remote station, said transfer means being operable to effect disconnection of the control means from the signal channel, and control switch means at the control station operable to selectively connect the signal channel to a direct current source at the control station with a polarity opposite that applied at the remote station.

2. A remote control system for a circuit breaker at a remote location connected to a control station over a signal channel consisting of a single pair of conductors comprising, switch means normally operable to energize the conductors from the remote location with polarities dependent on the breaker position, indicating means at the control station selectively responsive to the polarities of the conductors of the signal channel, control means at the remote location operable to effect operation of the breaker, and transfer means selectively operable from the control station over the same channel conductors, said transfer means being normally operable to render the control 10 means ineffective while the channel is energized from the remote location.

3. A remote control system for a circuit breaker at a remote location disposed to be connectedto a control station by a signal channel comprising, a pair of oppositely polarized breaker control relays at the remote location, transfer means normally operable to energize the signal channel from a direct current source at the remote location .and disconnect the control relays from the chem nel, breaker responsive means operable to vary the polarity of the channel, indicating means selectively responsive to the polarity of the channel, and control means at the control staticn operable to connect the signal channel to a direct current source at the control station opposite in polarity to that of the source atv the remote station.

4. In a remote control system for controlling apparatus at a remote location from a control station over a signal channel, switch means at the remote location disposed to connect the sige nal channel to a direct current source with a polarity dependent on the breaker position, relay means selectively responsive to the polarity of the channel to effect operation of the apparatus, transfer means normally operable to disconnect the relay means from the channel and connect the channel to the source at th remote station, and a control switch at the control station operable to selectively connect the channel to a source of direct current at the control station of the opposite polarity and effect operation of the transfer means to disconnect the channel from the source at the remote station and reconnect the relay means to the channel.

5. The combination in a control system for a circuit breaker at a remote'location having a signal channel connecting it to a control station, of a pair of polarized breaker control relays, transfer means normally operable to connect the signal channel to a direct current source at the remote breaker location and disconnect the control relays from the channel, switch means operable to reverse the connection of the signal channel to the source in accordance with the breaker position, polarized indicating means at the control station, and switch means at the control station operable to disconnect the indicating means from the channel and reversibly connect the channel to a direct current source at the control station, whereby the transfer means is rendered inoperative and one or the other of the control relays is operated,

6. In a remote control system for a circuit breaker at a remote location having a signal channel connection to a control station, a pair of oppositely polarized breaker control relays, transfer means disposed to connect th signal channel to a direct current source at the remote location and disconnect the control relays from the channel, a pair of oppositely polarized indicating relays at the control station, switch means at the remote location operable to reverse the connection of the channel and the sourc with the breaker position, additional switch means operable from a neutral position to reversibly connect the channel to a direct current source at the control station and effectively disconnect the indicating means from the channel, and line supervision means responsive to simultaneous deenergization of the indicating means when the additional switch means is in the neutral position.

'7. In a control system for a breaker at a reeans mote location connected by a signal channel to a control station, polarized control means for the breaker at the remote location, a line transfer relay operable to disconnect the control means from the signal channel and connect the channel to a direct current source at th remote location, switch means operable to connect the signal station to a direct current source at the control station, a synchronizing indication transmitter, relay means at the remote location operable in response to operation of the switch means to connect the synchronizing transmitter to the signal channel and disconnect the polarized control means from the channel, and an auxiliary control relay operable in response to operation of the relay means to efiect reconnection of the control means to the signal channel for effecting a closing operation of the breaker.

8. In a remote control system for a circuit breaker at a remote location connected by a signal channel to a control station, breaker control means at the remote location, breaker positlon indicating means at the control station, circuit means selectively connecting the channel to a source of direct current at the remote station in accordance with the breaker position, circuit means including a line transfer relay disposed to be connected in circuit relation with the signal channel and normally operable to connect the signal channel to a direct current source at the remote location, and switch means at the control station operable to selectively connect the indicating means in circuit relation with the signal channel or connect the signal channel to a direct current source at the control station for applying a voltage thereto in opposition to the voltage from the source at the remote station.

9. The combination in a control system for a remotely located circuit breaker having a direct wire signal channel connecting a control station to the remote circuit breaker location, of a pair of oppositely polarized breaker control relays at the remote location, transfer means disposed to be connected in series circuit relation with the signal channel normally operable to disconnect the polarized control relays from the channel and connect the channel to a direct current source at the remote location, breaker position responsive switch means disposed to change the connection of the channel to the source with the breaker position, oppositely polarized breaker position indicating means at the control station, and switch means at the control station normally connecting the indicating means to the signal 12 channel, said switch means being operable to reversibly connect the signal channel to a direct current source and disconnect the indicating means from the channel. I

10. In a control system for a remote circuit breaker at a location connected by a signal channel to a control station, a pair of oppositely polarized breaker control relays, transfer means normally operable to connect the signal channel to a direct current source at the remote location and disconnect the control relays therefrom, indicating means at the control station including a pair of polarized breaker position indicating relays and a synchronizing indicator, circuit means connecting the position indicating relays to the signal channel and operable to connect the signal channel to a direct current source at the control station, a synchronizing transmitter at the remote location, relay means operable in response to operation of the control means to connect the synchronizing transmitter to the channel, and additional control means disposed to be connected to the signal channel with the synchronizing transmitter operable to complete the connection of one of the control means to the signal channel.

11. In a remote control system for a remote breaker at a location disposed to be connected with a control station by a signal channel, breaker control means, relay means disposed for normally connecting the channel to a direct current source at the breaker location and disconnecting the breaker control means from the channel, synchronizing transmitter means at the breaker location, transmitter relay means operable in response to operation of th said relay means to connect the synchronizing transmitter to the signal channel, synchronizing indicating means, breaker position indicating means, and control switch means at the control station selectively operable to connect the indicating means to the signal channel or connect the channel to a direct current source.

WILLIAM F. CRUESS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,719,471 Hoffmann July 2, 1929 2,003,047 Henton et a1, May 28, 1935 2,240,638 De Croce May 6, 1941 2,342,125 Derr Feb. 22, 1944

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