US3883781A

US3883781A - Remote controlled circuit interrupter

Info

Publication number: US3883781A
Application number: US394906A
Authority: US
Inventors: John F Cotton
Original assignee: Westinghouse Electric Corp
Current assignee: ABB Inc USA
Priority date: 1973-09-06
Filing date: 1973-09-06
Publication date: 1975-05-13
Anticipated expiration: 1992-05-13
Also published as: AU497438B2; BR7407360D0; AU7262474A; BE819557A; CA1018217A

Abstract

A circuit breaker with a bimetal actuated latch, which controls both tripping and an overload indicator switch, is provided for emergency control the bimetal actuated latch is adjustable by a remotely controlled emergency control electric operator. An emergency control limit switch is provided so that the status of the emergency control electric operator can be remotely monitored. The circuit interrupter also has a remotely actuated motor operator which is controlled by a limit switch and cam arrangement to automatically shut off at the on and off positions of the circuit interrupter. A contact limit switch is provided to be actuated when the contacts of the circuit interrupter are open to indicate the status of the circuit interrupter. A remotely controlled reset solenoid is provided for resetting the overload indicator switch after it has been released by the bimetal actuated latch.

Description

United States Patent H 1 1111 3,883,781 Cotton 1 May 13, 1975 REMOTE CONTROLLED CIRCUIT [57] ABSTRACT INTERRUPTER [75] Inventor: John F. Cotton, Athens, Ga.

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Sept. 6, 1973 [21] Appl. No.: 394,906

[52] US. Cl 317/14 R; 317/58; 337/3; 337/47; 335/17; 335/68 {51] Int. Cl. H0lh 37/00 [58] Field of Search 337/47, 3; 335/17, 68;

[56] References Cited UNITED STATES PATENTS 2,686,242 8/1954 Leonard et al. 337/47 Primary E.raminerL. T. Hix Attorney, Agent, or Firm-H. G. Massung A circuit breaker with a bimetal actuated latch, which controls both tripping and an overload indicator switch, is provided for emergency control the bimetal actuated latch is adjustable by a remotely controlled emergency control electric operator. An emergency control limit switch is provided so that the status of the emergency control electric operator can be remotely monitored. The circuit interrupter also has a remotely actuated motor operator which is controlled by a limit switch and cam arrangement to automatically shut off at the on and off positions of the circuit interrupter. A contact limit switch is provided to be actuated when the contacts of the circuit interrupter are open to indicate the status of the circuit interrupter. A remotely controlled reset solenoid is provided for resetting the overload indicator switch after it has been released by the bimetal actuated latch.

32 Claims, 10 Drawing Figures NTED HAY I 3 SHEET 2 0f 7 FIG. 3.

SHEET 3 OF 7 E Z'JI'ENTEU PATENTED MY 1 3l975 SHEET 0F 7 zmxrama 14111 I 3 i515 883 781 SHEEI 5 0F 7 PATENTEB HAY 1 3 i975 SHEET E OF 7 REMOTE CONTROLLED CIRCUIT INTERRUPTER CROSS REFERENCE TO RELATED APPLICATIONS This invention is closely related to pending U.S. applications Patent Office Ser. No. 279,567 and Patent Office Ser. No. 279,565.

BACKGROUND OF THE INVENTION This invention relates to circuit breakers of the type having a bimetallic thermal trip element, and more particularly, to circuit breakers for distribution transformers to control moderate power distribution on feeder circuits.

In the patent to Leonard et al., U.S. Pat. No. 2,686,242, there is disclosed a circuit breaker similar to the circuit breaker herein disclosed, except that the circuit breaker in the Leonard et al patent does not include the remote monitoring and control features provided by the breaker disclosed in the present application. This invention is an improvement over the circuit breaker disclosed in the above-mentioned Leonard et al patent in that provisions for remote control and monitoring of the circuit breaker contacts, the overload signal switch and the emergency control adjustment is provided.

The disclosed circuit breaker is particularly adaptable for use with distribution transformers. Transformcrs used in power distribution systems are generally associated with protective devices which prevent or limit current overload damage to the transformer and its associated apparatus. The completely self-protected transformer includes a circuit breaker on the secondary or low voltage side to protect against damage due to overload currents. The secondary breaker disconnects the transformer from its load if the current becomes dangerously high.

Commonly used circuit breakers incorporate three basic features: (1) a low overload signal device, (2) an incremental load increase adjustment and (3) a tripping device to open the contacts of the circuit breaker upon a predetermined overload. As the load increases through the circuit breaker an overload point is reached at which the overload indicator switch closes and energizes a signal light on the outside of the transformer housing. The signal light, which is mounted on the transformer enclosure provides visual indication of when the secondary circuit breaker is about to trip. That is, the signal light is turned on at a lower overload current than that required to trip the breaker. The signal light remains on until reset even though the load current is later reduced to a satisfactory level. When line crews see an illuminated signal light, they are thereby given notice that a moderate overload condition has occurred. Repeated observations of an illuminated signal light usually indicate that the transformer should be replaced with a higher capacity transformer. The signal light also gives a quick and accurate visual indication of where a tripped breaker is located when a power outage occurs. As the load current continues to increase, a second overload point is reached where the circuit breaker trips open. The circuit breaker tripping protects the transformer against scvcre damage due to the flow of excessive overload currents.

To add extra loadability and minimize customer outagc until transformer changeover can be implemented, an incremental load increase adjustment or emergency control device is included in the circuit breaker. It is desirable in many applications to change the overload capacity ofa distribution transformer. In these applications, reducing the transformer life somewhat by sustaining a moderate overload is better than interrupting the load current and causing a power outage. As stated the completely self-protected transformer includes an emergency control device which effectively changes the rating of the contained circuit breaker. The emergency control mechanism may be moved from its normal position to an overload position to allow the resetting ofa tripped circuit breaker or the overload indicator. The rating of the circuit breaker may be increased by the emergency control mechanism for a short period of time until the bimetal actuated latch in the circuit breaker has cooled sufficiently to allow setting of the rating of the circuit breaker at its normal position.

A problem exists in that the versatility of present completely self-protected transformers is somewhat limited since visual observation of the protected transformer is necessary to determine the overload condition; and, the breaker and overload signal switch must be manually reset. It is desirable to have a circuit breaker for use in distribution transformers which provided remote signals to indicate if the overload signal switch has operated, if the contacts of the circuit breaker are open, or if the emergency control mechanism is in the overload position. It is also desirable to have a circuit breaker which provides for remote control of the circuit breaker contact mechanism, resetting of the overload indicator switch, or positioning of the emergency control mechanism.

SUMMARY OF THE lNVENTlON An improved circuit breaker providing for remote control and monitoring of contact position, overload signal indication, and emergency control setting is disclosed. In one embodiment the circuit breaker comprises an elongated movable contact arm that is pivotally connected intermediate the ends thereof to an operating link of a spring-type operating mechanism. The elongated movable contact arm is provided with a contact at one end for cooperating with a stationary contact. The contact arm is latched at the other end thereof by means of an elongated primary latch that is pivotally supported intermediate the ends thereof. The spring-type operating mechanism is operable between open and closed positions to pivot the contact arm about the latched end between open and closed positions, with a snap action. A bimetallic current actuated trip latch is provided. The bimetal latch comprises a second latch member that is latched by a bimetal activated latch and that is spring biased towards a tripping position. Upon the occurrence of a sustained overload above a predetermined value, the bimetal flexes with a time delay to release the second latch. The second latch then moves to strike the primary latch pivoting the primary latch to a position releasing the latched end of the contact arm. Thus, allowing spring means to bias the contact arm about the pivot of the operating link to a tripped open position.

The bimetal latch also latches a signal latch which is spring biased to close a pair of signal contacts when released. The signal latch is held to be released at an overload value which is less than that which releases the second latch and trips open the circuit breaker. Therefore, the signal latch is released prior to tripping open of the circuit breaker. A signal latch reset means is also provided to reset the signal latch in response to a remote control signal. In one embodiment of the invention the signal reset means comprises an electric solenoid which is connected by a wire formed link to the signal reset latch. The signal latch has a C-shaped portion with one end being linked by the wire formed linking member to the signal reset solenoid.

In one embodiment ofthe invention. an electric operator is provided to switch the circuit breaker between the open and closed positions. The electric operator comprises an electric motor which is linked to the spring operating mechanism to open and close the contacts of the circuit breaker. After activation power is fed to the electric operator through a limit switch which is cam controlled shut off only when the circuit breaker is in the on or off" position. That is, if the electric operator is energized momentarily by a remote signal. it will continue to run until the circuit breaker is switched to either the on or "of position. In one embodiment the electric operator comprises an electric motor which operates in one direction only. The electric motor is connected to a gear reducer which rotates a cam linked to the operating handle which forms part of the spring operating mechanism. Rotation of the operating cam switches the circuit breaker between the open and closed positions.

In one embodiment of the invention. a solenoid is provided for remote operation of the emergency control activator which essentially changes the rating of the circuit breaker. The solenoid can be activated from a remote signal to switch the emergency control mech anism to the higher overload position. A limit switch is provided for remotely indicating the position of the emergency control mechanism. Another limit switch is provided to be contacted by the movable contact when in the open position for remote indication of the position of the movable contact.

Power for operation of the disclosed circuit breaker can be provided for by placing a multiple conductor flat ribbon cable between the transformer coil and one loop of the core. The ends of the flat cable conductor are offset one conductor and spliced together to provide the desired operating voltage.

It is an object of this invention to provide a circuit breaker which can be remotely controlled to switch be tween the on" and of positions, to reset the overload indicator. and to position the emergency control.

It is a further object of this invention to provide a circuit breaker which can remotely indicate the status of the overload indicated. the emergency control and the main contacts.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of this invention. reference may be had to the preferred embodiment exemplary of the invention shown in the accompanying drawings in which:

FIG. I is a cutaway of a distribution transformer including a circuit breaker utilizing the teachings of the present invention;

FIG. 2 is a rear perspective view of a circuit breaker utilizing the teachings of the present invention;

FIG. 3 is a right side view of the circuit breaker shown in FIG. 2. with portions removed to show the circuit breaker operating mechanism more clearly,

FIG. 4 is a side view of a portion of the circuit breaker as shown in FIG. 3, with the overload signal latch in tripped position;

FIG. 5 is a front view of the circuit breaker shown in 5 FIG. 2;

FIG. 6 is a top view of the circuit breaker shown in FIG. 2;

FIG. 7 is a rear view of the circuit breaker shown in FIG. 2;

FIG. 8 is a top schematic view of a transformer core showing the flat ribbon conductor connector to supply power to operate the circuit breaker shown in FIG. 2;

FIG. 9 is a side view of FIG. 9; and

FIG. 10 is a schematic view showing electrical connection for the remote control features of the circuit breaker shown in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, and FIG. 1 in particular, there is shown a pole-type completely selfprotected distribution transformer I0 including a circuit breaker 26 utilizing the teaching of the present invention. The transformer 10 includes an enclosure [2 with a lightning arrester I4 and a primary bushing 16 mounted thereon. Secondary bushings such as the bushing 22 are attached to the enclosure 12. A signal light 24 is mounted on the enclosure 12 and is electrically connected to circuit breaker 26 to be activated at predetermined overloads. A core and coil assembly 28 is secured inside the enclosure 12 with the circuit breaker 26 attached thereto. Required winding leads 30 extend from the coil assembly to the appropriate bushings.

Referring now to FIGS. 2 through 8, the circuit breaker 26 comprises an insulating base or housing member 31 on which are mounted some parts of the breaker mechanism. The breaker operating mechanism comprises a stationary contact 23, a movable contact 25, a spring operating assembly indicated generally at 27 and a trip device indicated generally at 29. A spring 33 provides contact pressure in the closed position of

contacts

23 and 25. A motor operator assembly 90, a signal reset assembly 70 and an emergency control assembly 80, all of which will be described in more detail hereinafter, are also provided.

The movable contact 25 is fixedly mounted on one end of an elongated arm structure 35 that is latched at the one end 37 thereof in the operating position. as seen in FIG. 3, by means of an elongated primary latch member 39. The primary latch member 39 is mounted for pivotal movement intermediate the ends thereof. on a fixed pivot 40. The contact arm structure 35 com prises an elongated arm portion 41 and a U-shaped member 43 that carries the contact 25. U-shaped member 43 is mounted on portion 41 by means of a pivot pin 45 for limited movement relative to the arm portion 41, to provide contact alignment in the closed contact position. The movable contact 25 is fixedly mounted on the U-shaped member 43. The contact arm structure 35 is supported at 37 on a latch surface 47 of the primary latch 39. The contact arm 35 pivots on the latch surface 47 during manual operation of the circuit M breaker in a manner to be described hereinafter. A tension spring 49 is connected at one end thereof to an extension 51 of the contact arm structure 35 and at the other end thereof to a stationary spring support pin 53.

The contact arm structure 35 is pivotally connected intermediate the ends thereof to an operating link 55 by means of a pivot pin 57. A pair of operating springs 59 are connected at one end to a pin 61 on the upper end of the operating link 55 and at the other end to an insulating operating handle 63. The operating link 55 comprises twin members connected by means of the pin 61. A roller 65 is mounted on the pin 57 between the twin members of the link 55. A roller 67 is mounted on the pin 61 between the twin members of the link 55. The rollers 65, 67 are positioned in a generally triangular shaped opening 69 in the insulating housing 31. Rollers 65 and 67 engage the surfaces defining the opening 69 to guide movement ofthe operating link 55 in a manner to be described. The insulating handle 63 which is biased inward by means of the tension spring 59 rides on the arcuate surface 71 which guides the handle 63 for movement between the on and off positions.

In the closed position of the circuit breaker 26, the line of action of the operating spring 59 is below the point about which the handle 63 moves so that the springs 59 bias the handle 63 to the on position. The line of action of the springs 59 is also below the center about which the roller 67 travels on the surface 69 so that the roller 67 is biased to the right in the opening 69 to maintain the operating link 55 in the closed position. When the operating handle 63 is moved from the on position seen in full lines to the off positon (not shown), the line of action of the operating springs 59 moves to the left over the center about 61. When this occurs. a component of the force of the springs 59 biases the roller 67, causing the roller 67 together with the link 55 to move from the closed position seen in full lines to the open position (not shown), to pivot the movable contact arm structure 35 about the latch sur face 47. This movement of the operating link 55 and movable contact arm structure 35 occurs with a snap action.

The breaker 26 is closed by reverse movement of the handle 63 from the off position to the on position. During this movement, the line of action of the operating springs 59 crosses over the center about pin 61, whereupon the springs 59 bias the roller 67 to move the operating link 55 and movable contact arm structure 35 to the closed position with a snap action.

Referring to FIG. 3, it will be seen that in the closed position of the circuit breaker 26, the circuit extends from a conductor 165 through a conductor 121, stationary contact 23, the movable contact 25, the U- shaped member 43. flexible conductors 167 that are attached at one end to the member 43 and at the other end to a conductor 169, the conductor 169, a bimetal 171 that is connected at one end to the conductor 169 and at the other end to a conductor 173, the conductor 173 to a flexible conductor 175 that is connected to the conductor 173. The bimetal 171 is fixedly secured at the upper side thereof to an adjusting arm 170 that is suitably pivotally secured to the housing 31 in a manner more specifically described in the above-mentioned US. Pat. No. 2,686,242. A latch member 177 which is fixedly secured at one end thereof to the free end of bimetal 171 latches a second latching member 179 that is pivotally mounted on a stationary pivot 181 and that is biased in a clockwise direction by means of a tension spring 183.

When a persistent relatively low overload current above a predetermined value occurs in the circuit. the

bimetal 171 becomes heated and flexes with a time delay upward, whereupon the latch 177 releases the second latch member 179. Upon release of the second latch member 179, the spring 183 snaps the second latch member 179 clockwise about the pivot 181 causing the second latch member 179 to engage the end of the primary latch member 39 to pivot the primary latch member 39 in a counterclockwise direction about the fixed pivot 40 against the bias of spring 189. This moves the latch surface 47 to release the latched end 37 of the contact arm 35 whereupon the tension spring 49 moves the contact arm 35 about the pivot 57 to a tripped open position, with a snap action.

The operating mechanism is relatched and rrelatched following an automatic opening operation by moving the handle 63 to a position slightly past the off position. During this movement, one end of contact arm 35 engages a surface 191 on the insulating housing 31. This occurs when the operating link 55 is moved to the open position. The latching end 37 of the contact arm 35 is moved up over the latch surface 47 of the primary latch member 39, and as the handle 63 approaches the off position, a projection thereon engages the second latch member 179 to rotate the second latch member 179 counterclockwise about the pivot 18] whereupon the latch member 179 is again relatched by latch 177. When the second latch member 179 is moved to the latch position, a projection on latch member 179 moves away from the end of the primary latch member 39 and the spring 189 returns the primary latch member 39 to the latching position. This latches the contact arm 35 in the operating position. The movement of the primary latch member 39 to the latching position is stopped when the one end of the primary latch member 39 engages the projection 197 on the base 11.

Means is also provided for indicating an over load condition that is not of sufficient magnitude to trip the breaker 26 open, but which indicates that the current in the circuit is approaching a dangerous overload condition or that a dangerous overload condition has existed and has cleared itself without tripping the breaker. The signal indicating means also indicates that the breaker 26 has been tripped open in response to an overload current.

The signal indicating means comprises releasable sig nal member 146 pivotally supported by pivot pin 181. Member 146 is held by latch portion 177 carried by the bimetal element 171. Signal latch member 146 is biased in a clockwise direction by flat-formed spring 160. Flat formed spring 160 is held in position by

projections

162 and 164 formed in housing 31. Spring 160 is in contact with a conducting rod 166 which passes through housing 31. When signal latch member 146 is released by the bimetal actuated latch 177, flat spring 160 moves so as to contact support bolt 168. As can best be seen in FIG. 4, this completes circuit between conducting rod 166 and support bolt 168 through spring 160. Bolt 168 and flat spring 160 form the contacts which close the circuit, indicating that signal latch 146 has been released due to an overload condition. The releasable signal 146 is reset following an operation thereof by opration of the signal reset assembly or switching the circuit breaker handle 63 to the off position. The releasable signal member 146 is provided with a curved downwardly extending C-shaped arm 147 having a cam surface on the lower end thereof which is disposed in the path of the opening movement of the operating handle 63. Upon movement of the handle 63 to the off position, a portion of the handle 63 engages the cam surface on latch member 146 and rotates the releasable latch member 146 in a counterclockwise dircction to permit rcengagement of the latch member 146 with the latch 177. This action also moves the flat spring 160 out of engagement with mounting bolt [68 and opens the signal circuit.

The signal latch 146 can also be reset with the signal reset assembly 70. The signal reset assembly 70 com prises a signal sheet solenoid 72 and a reset linkage 74. An opening 76 is formed in the bottom of the C-shaped portion 147 of the signal latch 146. Opening 76 is engaged by reset linkage 74 which is connected to reset solenoid 72. By energizing signal sheet solenoid 72, signal latch 146 can be rotated in a counterclockwise direction and thus be reset to the latched position. The signal reset solenoid 72 permits the signal latch 146 to be reset from a remote location, and the signal circuit formed by flat formed spring 160 between conducting rod 166 and bolt 168 permits the status of the signal latch 146 to be remotely monitored,

An operator assembly 90 is also provided to switch the

circuit breaker contacts

23 and 25 between the open and closed positions. A limit switch 110 is attached to the base of breaker 26 and is disposed so that when contact 25 is in the open position, limit switch 110 is engaged. Thus, a circuit formed through limit switch 110 can be used to remotely determine the status of the

contacts

23 and 25. The operator assembly 90 is constructed so as to facilitate activation from a remote location. When operator assembly 90 is activated, it will stay energized until circuit breaker 26 is switched either from the on position to the off position or from the off position to the on position. Operator assembly 90 comprises a gear motor 9!, a crank 92, a connecting rod 93 and a lifter link 94. Lifter link 94 is connected to operating rod 95 which is connected to the handle 63 ofa circuit 26. Lever 89 which engages lifter link 94 is provided to guide lifter link 94 and to hold lifter link 94 in position. Gear motor 9i comprises an electric motor 96 and a gear box 97. The output shaft of electric motor 96 is connected to the input shaft of gear reducer 97. Crank 92 is attached to the output shaft of gear box 97. A crank 92 is rotated due to activation of drive motor 96, handle 63 of circuit breaker 26 is moved between the on and off positions. Operating handle 63 is moved between the on and off positions without changing the direction of rotation of electric motor 96. A cam 98 is also attached to the output shaft of gear motor 91. Cam 98 is constructed so as to engage a limit switch 99 during predetermined cam rota tion. Electric motor 96 is fed power through limit switch 99 so that, by proper construction of cam 98, operation of electric motor 96 can be controlled. In a normal cycle, as crank 92 is rotated 360, operating handle 63 is switched from the on position to the off position after a 180 rotation and then is switched from the off position back to the on position after a full 360 rotation, By constructing cam 98 with indentations at 180 spacing and having limit switch 99 disposed so as to be open when the operating lever 199 is released in one of the indentations. the electric motor 96 once activated will continue to operate until crank 92 is rotated l80 and circuit breaker 26 is switched. That is. a remote signal can activate gear motor 91 and gear motor 9| will continue to operate even after removal of the remote activation signal until crank 92 is rotated 180, changing the state of

circuit breaker contacts

23 and 25. Thus, means are provided by limit switch 110 and operator assembly 90 for remotely monitoring and controlling the status of the

main contacts

23 and 25 in circuit 26.

Two or more of the circuit breakers 26 may be assembled and tied together for unitary operation to control a circuit While only a single pole circuit breaker 26 has been described in detail it is to be understoood that operation of multipole units will be similar. When two or more breakers 26 are assembled together a single cover plate is disposed between adjacent breakers 26 and a eoverplate is mounted on the outsides of the breaker unit. The breaker operating handles are joined together by a rod 95.

It is at times essential that the service of a transformer be restored at least temporarily immediately after a circuit has been opened by operation of the transformer breaker in response to an overload condition. However, there are occasions where it is difficult or impossible to reclose the breaker 26, especially ifthe oil has been heated by a long continued overload current or due to a high ambient temperature, because the hot oil maintains the bimetal element 17] deflected to its tripped position and the spring mechanism 27 cannot be relatched. Emergency control is provided for emergency adjustment of the bimetallic element 171, from a remote location, to permit the circuit breaker to be closed and latched immediately upon a tripping operation. Emergency control 80 permit the breaker 26 to temporarily carry a certain percentage of overload current for a predetermined time. The emergency control assembly 80 essentially permits remote changing of the circuit breaker 26 rating. Emergency control adjustment 80 of circuit breaker 26 comprises the pivoted mounting of the bimetal element 171 and the adjusting screw 127. Mounted on the adjusting screw [27 for each of the breaker units is an arm 225. The arms 225 are placed over the adjusting screws 127 after the adjusting screws 127 have been adjusted to give proper tripping. The arms 225 are securely connected to the adjusting screws 127 so as to provide a fixed connection. When more than one circuit breaker 26 unit is used, the arms 225 of the circuit breaker unit are con nected by means of a link 227 for unitary movement. A lever 81 pivoted about point 82 is connected at one end to emergency control solenoid 83 and at the other end to link 227. A relatively long bolt 84 is used to connect the one end of lever 81 to link 227. Bolt 84 is connected so as to provide some degree of flexibility or movement between the end of lever 81 and connecting link 227. The other end oflever 81 is connected by link 85 to the operating rod 86 extending from solenoid 83. In operation emergency control solenoid 83 acts through

linkage members

81, 85. 84 and 227 to simultaneously rotate the arms 225 and adjusting screws [27 a predetermined distance in a clockwise direction as viewed in FIG. 6. This movement of adjusting screws 127, each of which threadedly engages a corresponding adjusting rod causes clockwise rotation of the arm I70 upon which the bimetal element 171 is mounted, This moves the latch portion 177 to the latching position even though the bimetal remains in a deflected condition and permits relatching of the spring operating mechanism 27 of the breaker 26. Operating the emergency control assembly 80 also permits the signal latch 146 to be reset even though an overload condition exists, Operating the emergency control solenoid 83 increases the trip temperature setting of the bimetal element 171 and requires a greater overload to trip the second breaker latch [79 or the overload signal latch 146. By this emergency adjustment, the breaker 26 will carry a given overload for a predetermined time, but will still trip out in response to higher overload or short circuit currents. After the overload has cleared, the emergency adjusting means may be restored to its original position by deenergizing solenoid 83 and placing the transformer back in normal use. Emergency control limit switch 101 is mounted on the breaker so to be engaged by link 81 when in the deenergized position. A circuit through emergency control limit switch 101 can thus indicate the status of the emergency control assembly 80. That is, the switch 101 can be used to provide a remote indication of whether or not the emergency control assembly 80 is activated and the breaker is in an increased overload mode.

A trip bar 50 extends across the back of the circuit breaker unit 26. This is mechanically linked by a pushpull cable 52 to an operating handle 54 located on the exterior of the transformer tank 12. This trip mechanism can be used in the event of primary power failure and thus loss of the control voltage to open the breaker before restoring power. This handle 50 is held positively in the trip position to insure safety for lineman while servicing the secondary side of the tranformer 10. This manual device prevents remote closure of the circuit breaker 26 by activation of the operator assembly 90 during the service procedures.

It can be seen that this invention provides a circuit breaker 26 especially adaptable for remote operation and control. The status and position of the

main contacts

23 and 25 can be determined and controlled by operator assembly 90 and limit switch H0. The emergency control can be positioned and monitored remotely through the emergency control assembly 80 and limit switch 101. The overload signal circuit can be monitored and controlled remotely through use of the signal reset assembly 70.

Pushbuttons can be supplied at the transformer 10 to provide for on-site operation or control of the abovedescribed features. A typical electric schematic for remote surveillance and control of circuit breaker 26 is shown in FIG. 10. In this schematic, one push-button 17 is provided for on-site operation of the breaker operator control motor 91. The signal reset solenoid 72 can be remotely operated by closing contacts 18. Emergency control advance solenoid 83 can be operated by remotely closing contacts 19. The circuit breaker 26 can be switched on and off by remotely closing contacts 20 which activates the operator motor 91. Motor 91 then continues to run through limit switch 99 until a predetermined position is reached. Closing of limit switch 101 indicates the emergency control 80 status. Closing of limit switch 110 indicates

main breaker contacts

23 and 25 status.

Power for operation of the above-described electric circuit breaker 26 is provided for by placing a multiple conductor flat ribbon cable H2 between the transformer coil 113 and one loop ofthe core 114. The ends of the flat cable conductor are offset one conductor and spliced together as seen in drawings 8 and 9. To achieve a normal 24 volt AC as required, the 24 volts is divided by the working voltage per turn of the core and rounded to the nearest whole number. This then is the number of conductors at the splice that are bridged to achieve the approximate 24 volt AC required. For example, on a transformer core designed for 7 volts per turn, each conductor of the flat multiple ribbon cable picks up 3.5 volts when it passes through one core loop. If the control voltage required is 24 volts, 24 is divided by 3.5, yielding 6,85, rounding this to the nearest whole number 7, indicates that 7 strands must be bridged at the splice to obtain a supply voltage of approximately 24 volts. Using multiple conductor ribbon conductors 112 to provide the control voltage to operate circuit breaker 26 allows circuit breaker 26 to be easily installed in transformers l0 accommodating various working voltage coil designs. Use of multiple conductor ribbon conductors facilitates installation of control windings.

In the disclosed invention, a circuit breaker 26 is provided having a solenoid actuated signal latch reset assembly 70, a solenoid actuated emergency control ad vance linkage and bell crank assembly 80, an operator assembly having a unidirectional gear motor driven crank and crank rod breaker open and breaker closed and reset assembly. The gear motor driven crank assembly is provided with an internal cam to actuate limit switches for self-deenergization at predetermined points where the breaker is in the open position and/or in the closed position.

I claim:

I. A circuit breaker comprising:

a stationary contact;

a movable contact;

an elongated contact arm carrying said movable contact at one end thereof;

a primary latch supported for movement about a first axis and being in a latching position, latching the other end of said elongated contact arm;

a second latch in a latched position;

biasing means biasing said second latch toward a tripping position;

a bimetal actuated latch latching said second latch in the latched position;

a spring operating mechanism pivotally connected to said contact arm intermediate the end of said contact arm and being operable to pivot said contact arm about said other end on said primary latch between open and closed positions with a snap action;

a signal latch in a latched position;

said bimetal actuated latch latching said signal latch in the latched position;

a pair of signal contacts associated with said signal latch and being movable from an open to a closed position when said signal latch is released;

said bimetal actuated latch being responsive to current flowing through the circuit breaker so upon the occurrence of lesser overloads above a predetermined value, said bimetal actuated latch releases said signal latch, whereupon said pair of signal contacts moves to a closed position and upon the occurrence of a greater overload above a predetermined value, said bimetal actuated latch also releases said second latch, whereupon said biasing means moves said second latch to effect movement of said primary latch to unlatch said elongated contact arm, whereupon said spring operating mechanism moves said contact arm to a tripped open position; and,

signal reset means being responsive to an electric signal to reset said signal latch in a latch position.

2. A circuit breaker as claimed in claim 1, comprising:

a spring biasing means for biasing said signal latch towards an unlatched position; and

said spring biasing means forming one of said pair of signal contacts.

3. A circuit breaker as claimed in claim 1, wherein:

said signal reset means comprises an electric solenoid linked to said signal latch to reset said signal latch when activated.

4. A circuit breaker as claimed in claim 3, comprising:

a handle mechanism movable between an on and an off position connected to said spring operating mechanism;

said signal latch having a C-shaped portion with one end being linked by a wire-formed member to said signal reset means; and

said signal latch being disposed so as to contact and be reset by said handle when said handle is moved to the off position.

5. A circuit breaker as claimed in claim 4, comprising:

a flat-formed spring biasing said signal latch towards an unlatched position; and

said flat-formed spring forming one ofsaid pair of signal contacts.

6. A circuit breaker as claimed in claim 4, comprising:

an electric motor;

said electric motor being connected to said spring operating mechanism to move said primary latch between open and closed positions in response to a remote signal.

7. A circuit breaker as claimed in claim 1, including:

an electric operator;

said electric operator being responsive to a remote electric signal to move said movable contact between open and closed position.

8. A circuit breaker as claimed in claim 6, comprising:

a handle movable between an on and off position connected to said spring operating mechanism to operate said spring operating mechanism;

a gear reducer connected to the output shaft of said motor;

a cam connected to the output shaft of said gear reducer;

linkage means connecting said cam to said handle of said circuit breaker so that said handle mechanism is moved between the on and off positions while said electric motor is run in one direction.

9. A circuit breaker as claimed in claim 8, including:

means for stopping said electric motor with said handle located at predetermined positions.

10. A circuit breaker as claimed in claim 9, wherein said means to stop said motor comprises:

a limit switch through which power flows to said electric motor;

a cam attached to the output shaft of said gear rc ducer;

said cam and said limit switch being cooperatively associated to interrupt electric power to said motor at predetermined positions of said cam.

11. A circuit breaker as claimed in claim 6, including;

an emergency control activator;

connecting means connecting said emergency control activator to said bimetal actuated latch so that when said emergency control activator is moved. the value of the current required to cause said bimetal actuated latch to release said signal latch and said second latch is varied.

12. A circuit breaker as claimed in claim 11, comprising:

an electric operator assembly remotely controlled for positioning said emergency control activator.

13. A circuit breaker as claimed in claim 12, wherein said electric operator comprises:

an electric solenoid;

emergency control linkage means for connecting said electric solenoid to said emergency control activator so that when said electric solenoid is activated, the position of said emergency control activator is correspondingly changed; and including,

emergency control limit switch disposed so as to indi cate the status of said emergency control activator.

14. A circuit breaker as claimed in claim 11, comprising a contact limit switch;

said contact limit switch being disposed so as to engage said elongated contact arm when said movable contact is separated from said stationary contact so as to be activated when said circuit breaker is open.

15. A circuit breaker comprising:

a stationary contact;

a movable contact movable between a closed position in engagement with said stationary contact and an open position spaced from said stationary contact;

an elongated contact arm carrying said movable contact at one end thereof;

a primary latch supported for movement about a first axis and being in a latching position to latch the other end of said elongated contact arm;

a second latch held in a latched position;

biasing means biasing said second latch toward a tripping position;

a bimetal activated latch latching said second latch in the latched position;

a spring operated mechanism pivotally connected to said contact arm intermediate the ends of said contact arm and being operable to pivot said contact arm about said other end on said primary latch between open and closed positions with a snap action;

said bimetal actuated latch being responsive to current flow through the circuit breaker so upon the occurrence of a selected overload above a predetermined value said bimetal actuated latch release said second latch, whereupon said biasing means moves said second latch to effect movement of said primary latch to unlatch said contact arm. whereupon said spring operating mechanism moves said contact arm to a tripped open position;

an emergency control activator being connected to said bimetal actuated latch so as to change the selected overload above which said bimetal actuated latch releases said second latch; and

an emergency control solenoid connected to said emergency control activator to move said emergency control activator in response to a remote signal so as to change the selected overload current at which said circuit breaker is tripped open,

16. A circuit breaker as claimed in claim 15, including;

an emergency control limit switch positioned so as to be activated when said emergency control solenoid is operated to indicate the status of said emergency control activator.

17. A circuit breaker as claimed in claim 16, comprising:

a contact position switch;

ing handle mechanism is moved between the on and of! positions as said operating cam is rotated by said electric motor gear reducer;

a limit switch completing an electric circuit to said electric motor and being disposed so as to be activated by said control cam at discrete positions to control operation of said electric motor.

22. A circuit interrupter including a motor operator for remote control. comprising:

said contact position switch being located so as to be 15 a Stationary Contact? closed by said elongated contact arm when said Y being f l between a Closed movable contact is separated from said stationary posmo m hm with Sam StanOllar-V cfmmcl Contact and the Circuit breaker is opcnedl and an open position spaced from said stationary 18. A circuit breaker comprising: Contact".

a Staticnary Contact; an operating means connected to said movable a movable Contact; contact :10 rilnov:I said movable contact between the an elongated contact arm carrying said movable Oplcn C 05L i with a f Contact a one end thereof; an e CCII'IS motohr aving an outpuhtsf a t, d

a primary latch supported for movement about a a g i .3 f 5 5 l fixed axis and being in a latching position, latching I t a on 5d] g Sig i Oupm s the other end of said elongated contact arm; Opera mg Cam mums L 0 e re 0U put shaft;

a second latch in a latched position,

. a linkage connecting said operating cam to said operbiasing means biasing said second latch toward a trip- 4 v ating means so that said movable contact is moved ping position; t

. v i between the open and closed positions as said cam 21 bimetal actuated latch latching said second latch in i t is rotated by said electric motor. the latched position; 2 i y g t i 3. A circuit interrupter as claimed in claim 22 ina spring operating mechanism pivotally connected to eluding Said connected arm nltermedlate the encls 0f i an electric supply line feeding power to said electric contact arm and being operable to pivot said motor i s: arm about the a on i ma :1 motor operator limit switch having a pair of F Open C Use posmons d contacts inserted in series with said electric supply snap action, I line;

bald blmetal uctumcd latch bedng sponme to i a control cam attached to the output shaft of said mm flow through the C'rclm breaker 5O up(m t g 40 gear reducer and being cooperatively associated occurrenlcc Overload above a predetermined with said motor operator limit switch to open said value, said bimetal actuated latch relcascs 5316 electric supply line when the circuit interrupter is i latch whereupon Stud biasing means 9 in the open position and also when the circuit intersaid second latch to effect movement of said prirupter is in mg Closed position mary latch to unlatch said contact arm whereupon A Circuit interrupter Comprising; said spring operating mechanism moves said a Stationary Contact; comflct mm m a pp P l j i a movable contact being movable between a closed P i' Cnmm] means conncclcd P P position in engagement with the said stationary erfmng i f f for Operating Said iz t l contact and an open position spaced from said staating mec anism in response 0 a remo e signa lionary Contact.

19. A circuit breaker as claimed in claim 18, wherein an opgranng means md to id bi said operating C ntr l m an COmPTISCSI contact to move said movable contact between the an ele tric motor having an output h open and closed positions with a snap action;

11 Tedilcer having an input Shaft Connccwd m the as a bimetal actuated latch latching said movable output shaft of said electric motor and having an Contact i h clggcd i output shaft; spring biasing means connected to said movable an operating Cam i m h t0 the Output Shaft Oi Silld contact to bias said movable contact towards the gear reducer; open position;

a handle mechanism connected to said spring operatid bim tal actuated latch being responsive to curing mechanism and being movable between an on rent flow through the circuit interrupter so upon and an off position to move said movable contact the occurrence of a tripping overload current from the closed position to the Open po iti n. above a predetermined value, said bimctal actulinkage means connecting said handle mechanism to ated latch releases said movable contact where said operating cam mechanism so that said operat- 68 upon said circuit interrupter opens;

an emergency control actuator connected to said bimetal actuated latch and being movable between a normal position in which said bimetal actuated latch releases at predetermined current overload and an overload position wherein said bimetal actuated latch trips at a current level greater than the predetermined overload current; and

an electric solenoid connected to said emergency control activator to move said emergency control activator between the normal position and the overload position in response to a remote signal.

25. A circuit interrupter as claimed in claim 24, including:

an emergency control limit switch;

linkage means connecting said emergency control activator to said electric solenoid;

said emergency control limit switch being cooperatively associated with said emergency control linkage means so as to indicate the status of said emergency control activator.

26. A circuit breaker as claimed in claim 25, including a electric operator being remotely controlled and connected to said operating means to activate said operating means in response to a remote control signal.

27. A circuit interrupter as claimed in claim 26, including a limit switch disposed so as to contact said movable contact when said movable contact is in the open position, to thereby indicate the position of said movable contact.

28. A distribution transformer including:

a housing;

a core disposed within said housing;

a circuit interrupted disposed within said housing and being switchable between an open position, wherein the electrical connections through said transformer are open, and a closed position, wherein the electrical connections through said transformer are closed. in response to a remote signal;

an electric operator connected to said circuit interrupter and disposed within said housing for switching said circuit interrupter between an open and closed position in response to the remote signal; and

a control winding surrounding a portion of said core for supplying electric power to energize said electric operator.

29. A transformer as claimed in claim 28 wherein said control winding comprises;

a flat multiconductor cable disposed around a portion of said core; and

said flat multiconductor cable being connected with the ends of said flat multiconductor cable offset one conductor and spliced together to provide the desired operating voltage.

30. A distribution transformer as claimed in claim 29,

wherein said circuit interrupter comprises:

a stationary contact;

a movable contact;

an elongated contact arm carrying said movable contact at one end thereof;

a primary latch supported for movement about a fixed axis and being in a latching position, latching the other end of said elongated contact arm;

a second latch in a latched position;

biasing means biasing said second latch toward a tripping position;

a bimetal actuated latch latching said second latch in the latched position;

a spring operating mechanism pivotally connected to said contact arm intermediate the ends of said contact arm and being operable to pivot said contact arm about the other end of said primary latch between open and closed positions with a snap action;

said bimetal actuated latch being responsive to current flow through the circuit breaker so upon the occurrence of overload above a predetermined value, said bimetal actuated latch releases said second latch whereupon said biasing means moves said second latch to effect movement of said primary larch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to a tripped open position; and.

said electric operator being connected to said spring operating mechanism for operating said spring operating mechanism in response to a remote signal.

31. A distribution transformer as claimed in claim 30,

wherein said electric operator comprises:

an electric motor having an output shaft;

a gear reducer having an input shaft connected to the output shaft of said electric motor and having an output shaft;

an operating cam attached to the output shaft of said gear reducer;

a handle mechanism connected to said spring operating mechanism and being movable between an on and an off position to move said movable contact from the closed position to the open position;

linkage means connecting said handle mechanism to said operating cam mechanism so that said operating handle mechanism is moved between the on and off positions as said operating cam is rotated by said electric motor.

32. A distribution transformer as claimed in claim 31,

comprising:

a contact position switch;

said contact position switch being located so as to be closed by said elongated contact arm when said movable contact is separated from said stationary contact and said circuit interrupter is opened. Q

Claims

1. A circuit breaker comprising: a stationary contact; a movable contact; an elongated contact arm carrying said movable contact at one end thereof; a primary latch supported for movement about a first axis and being in a latching position, latching the other end of said elongated contact arm; a second latch in a latched position; biasing means biasing said second latch toward a tripping position; a bimetal actuated latch latching said second latch in the latched position; a spring operating mechanism pivotally connected to said contact arm intermediate the end of said contact arm and being operable to pivot said contact arm about said other end on said primary latch between open and closed positions with a snap action; a signal latch in a latched position; said bimetal actuated latch latching said signal latch in the latched position; a pair of signal contacts associated with said signal latch and being movable from an open to a closed position when said signal latch is released; said bimetal actuated latch being responsive to current flowing through the circuit breaker so upon the occurrence of lesser overloads above a predetermined value, said bimetal actuated latch releases said signal latch, whereupon said pair of signal contacts moves to a closed position and upon the occurrence of a greater overload above a predetermined value, said bimetal actuated latch also releases said second latch, whereupon said biasing means moves said second latch to effect movement of said primary latch to unlatch said elongated contact arm, whereupon said spring operating mechanism moves said contact arm to a tripped open position; and, signal reset means being responsive to an electric signal to reset said signal latch in a latch position.

2. A circuit breaker as claimed in claim 1, comprising: a spring biasing means for biasing said signal latch towards an unlatched position; and said spring biasing means forming one of said pair of signal contacts.

3. A circuit breaker as claimed in claim 1, wherein: said signal reset means comprises an electric solenoid linked to said signal latch to reset said signal latch when activated.

4. A circuit breaker as claimed in claim 3, comprising: a handle mechanism movable between an on and an off position connected to said spring operating mechanism; said signal latch having a C-shaped portion with one end being linked by a wire-formed member to said signal reset means; and said signal latch being disposed so as to contact and be reset by said handle when said handle is moved to the off position.

5. A circuit breaker as claimed in claim 4, comprising: a flat-formed spring biasing said signal latch towards an unlatched position; and said flat-formed spring forming one of said pair of signal contacts.

6. A circuit breaker as claimed in claim 4, comprising: an electric motor; said electric motor being connected to said spring operating mechanism to move said primary latch between open and closed positions in response to a remote signal.

7. A circuit breaker as claimed in claim 1, including: an electric operator; said electric operator being responsive to a remote electric signal to move said movable contact between open and closed position.

8. A circuit breaker as claimed in claim 6, comprising: a handle movable between an on and off position connected to said spring operating mechanism to operate said spring operating mechanism; a gear reducer connected to the output shaft of said motor; a cam connected to the output shaft of said gear reducer; linkage means connecting said cam to said handle of said circuit breaker so that said handle mechanism is moved between the on and off positions while said electric motor is run in one direction.

9. A circuit breaker as claimed in claim 8, including: means for stopping said electric motor with said handle located at predetermined positions.

10. A circuit breaker as claimed in claim 9, wherein said means to stop said motor comprises: a limit switch through which power flows to said electric motor; a cam attached to the output shaft of said gear reducer; said cam and said limit switch being cooperatively associated to interrupt electric power to said motor at predetermined positions of said cam.

11. A circuit breaker as claimed in claim 6, including: an emergency control activator; connecting means connecting said emergency control activator to said bimetal actuated latch so that when said emergency control activator is moved, the value of the current required to cause said bimetal actuated latch to release said signal latch and said second latch is varied.

12. A circuit breaker as claimed in claim 11, comprising: an electric operator assembly remotely controlled for positioning said emergency control activator.

13. A circuit breaker as claimed in claim 12, wherein said electric operator comprises: an electric solenoid; emergency control linkage means for connecting said electric solenoid to said emergency control activator so that when said electric solenoid is activated, the position of said emergency control activator is correspondingly changed; and including, emergency control limit switch disposed so as to indicate the status of said emergency control activator.

14. A circuit breaker as claimed in claim 11, comprising a contact limit switch; said contact limit switch being disposed so as to engage said elongated contact arm when said movable contact is separated from said stationary contact so as to be activated when said circuit breaker is open.

15. A circuit breaker comprising: a stationary contact; a movable contact, movable between a closed position in engagement with said stationary contact and an open position spaced from said stationary contact; an elongated contact arm carrying said movable contact at one end thereof; a primary latch supported for movemeNt about a first axis and being in a latching position to latch the other end of said elongated contact arm; a second latch held in a latched position; biasing means biasing said second latch toward a tripping position; a bimetal activated latch latching said second latch in the latched position; a spring operated mechanism pivotally connected to said contact arm intermediate the ends of said contact arm and being operable to pivot said contact arm about said other end on said primary latch between open and closed positions with a snap action; said bimetal actuated latch being responsive to current flow through the circuit breaker so upon the occurrence of a selected overload above a predetermined value, said bimetal actuated latch release said second latch, whereupon said biasing means moves said second latch to effect movement of said primary latch to unlatch said contact arm, whereupon said spring operating mechanism moves said contact arm to a tripped open position; an emergency control activator being connected to said bimetal actuated latch so as to change the selected overload above which said bimetal actuated latch releases said second latch; and an emergency control solenoid connected to said emergency control activator to move said emergency control activator in response to a remote signal so as to change the selected overload current at which said circuit breaker is tripped open.

16. A circuit breaker as claimed in claim 15, including: an emergency control limit switch positioned so as to be activated when said emergency control solenoid is operated to indicate the status of said emergency control activator.

17. A circuit breaker as claimed in claim 16, comprising: a contact position switch; said contact position switch being located so as to be closed by said elongated contact arm when said movable contact is separated from said stationary contact and the circuit breaker is opened.

18. A circuit breaker comprising: a stationary contact; a movable contact; an elongated contact arm carrying said movable contact at one end thereof; a primary latch supported for movement about a fixed axis and being in a latching position, latching the other end of said elongated contact arm; a second latch in a latched position; biasing means biasing said second latch toward a tripping position; a bimetal actuated latch latching said second latch in the latched position; a spring operating mechanism pivotally connected to said connected arm intermediate the ends of said contact arm and being operable to pivot said contact arm about the other end on said primary latch between open and closed positions with a snap action; said bimetal actuated latch being responsive to current flow through the circuit breaker so upon the occurrence of overload above a predetermined value, said bimetal actuated latch releases said second latch whereupon said biasing means moves said second latch to effect movement of said primary latch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to a tripped open position; and operating control means connected to said spring operating mechanism for operating said spring operating mechanism in response to a remote signal.

19. A circuit breaker as claimed in claim 18, wherein said operating control means comprises: an electric motor having an output shaft; a gear reducer having an input shaft connected to the output shaft of said electric motor and having an output shaft; an operating cam attached to the output shaft of said gear reducer; a handle mechanism connected to said spring operating mechanism and being movable between an on and an off position to move said movable contact from the closed position to the open position; linkage means connecting said handle mechanism to said operating cam mechanism so that said operating handle mechanism is moved between the on and off positions as Said operating cam is rotated by said electric motor.

20. A circuit breaker as claimed in claim 19, wherein said electric motor is operable in one direction only.

21. A circuit breaker as claimed in claim 19, including means for stopping said electric motor when said operating handle mechanism is in a predetermined position, comprising: a control cam attached to the output shaft of said gear reducer; a limit switch completing an electric circuit to said electric motor and being disposed so as to be activated by said control cam at discrete positions to control operation of said electric motor.

22. A circuit interrupter including a motor operator for remote control, comprising: a stationary contact; a movable contact, being movable between a closed position in engagement with said stationary contact and an open position spaced from said stationary contact; an operating means connected to said movable contact to move said movable contact between the open and closed positions with a snap action; an electric motor having an output shaft; a gear reducer having an input shaft, connected to the output shaft of said motor, and an output shaft; an operating cam connected to the gear reducer output shaft; a linkage connecting said operating cam to said operating means so that said movable contact is moved between the open and closed positions as said cam is rotated by said electric motor.

23. A circuit interrupter as claimed in claim 22 including: an electric supply line feeding power to said electric motor; a motor operator limit switch having a pair of contacts inserted in series with said electric supply line; a control cam attached to the output shaft of said gear reducer and being cooperatively associated with said motor operator limit switch to open said electric supply line when the circuit interrupter is in the open position and also when the circuit interrupter is in the closed position.

24. A circuit interrupter comprising: a stationary contact; a movable contact being movable between a closed position in engagement with the said stationary contact and an open position spaced from said stationary contact; an operating means connected to said movable contact to move said movable contact between the open and closed positions with a snap action; a bimetal actuated latch latching said movable contact in the closed position; spring biasing means connected to said movable contact to bias said movable contact towards the open position; said bimetal actuated latch being responsive to current flow through the circuit interrupter so upon the occurrence of a tripping overload current above a predetermined value, said bimetal actuated latch releases said movable contact whereupon said circuit interrupter opens; an emergency control actuator connected to said bimetal actuated latch and being movable between a normal position in which said bimetal actuated latch releases at predetermined current overload and an overload position wherein said bimetal actuated latch trips at a current level greater than the predetermined overload current; and an electric solenoid connected to said emergency control activator to move said emergency control activator between the normal position and the overload position in response to a remote signal.

25. A circuit interrupter as claimed in claim 24, including: an emergency control limit switch; linkage means connecting said emergency control activator to said electric solenoid; said emergency control limit switch being cooperatively associated with said emergency control linkage means so as to indicate the status of said emergency control activator.

28. A distribution transformer including: a housing; a core disposed within said housing; a circuit interrupted disposed within said housing and being switchable between an open position, wherein the electrical connections through said transformer are open, and a closed position, wherein the electrical connections through said transformer are closed, in response to a remote signal; an electric operator connected to said circuit interrupter and disposed within said housing for switching said circuit interrupter between an open and closed position in response to the remote signal; and a control winding surrounding a portion of said core for supplying electric power to energize said electric operator.

29. A transformer as claimed in claim 28 wherein said control winding comprises; a flat multiconductor cable disposed around a portion of said core; and said flat multiconductor cable being connected with the ends of said flat multiconductor cable offset one conductor and spliced together to provide the desired operating voltage.

30. A distribution transformer as claimed in claim 29, wherein said circuit interrupter comprises: a stationary contact; a movable contact; an elongated contact arm carrying said movable contact at one end thereof; a primary latch supported for movement about a fixed axis and being in a latching position, latching the other end of said elongated contact arm; a second latch in a latched position; biasing means biasing said second latch toward a tripping position; a bimetal actuated latch latching said second latch in the latched position; a spring operating mechanism pivotally connected to said contact arm intermediate the ends of said contact arm and being operable to pivot said contact arm about the other end of said primary latch between open and closed positions with a snap action; said bimetal actuated latch being responsive to current flow through the circuit breaker so upon the occurrence of overload above a predetermined value, said bimetal actuated latch releases said second latch whereupon said biasing means moves said second latch to effect movement of said primary larch to unlatch said contact arm whereupon said spring operating mechanism moves said contact arm to a tripped open position; and, said electric operator being connected to said spring operating mechanism for operating said spring operating mechanism in response to a remote signal.

31. A distribution transformer as claimed in claim 30, wherein said electric operator comprises: an electric motor having an output shaft; a gear reducer having an input shaft connected to the output shaft of said electric motor and having an output shaft; an operating cam attached to the output shaft of said gear reducer; a handle mechanism connected to said spring operating mechanism and being movable between an on and an off position to move said movable contact from the closed position to the open position; linkage means connecting said handle mechanism to said operating cam mechanism so that said operating handle mechanism is moved between the on and off positions as said operating cam is rotated by said electric motor.

32. A distribution transformer as claimed in claim 31, comprising: a contact position switch; said contact position switch being located so as to be closed by said elongated contact arm when said movable contact is separated from said stationary contact and said circuit interrupter is opened.