US2937320A - Circuit interrupter - Google Patents

Description

May 17, 1960 Filed Sept. 24, 1957 G. J. EASLEY CIRCUIT INTERRUPTER 3 Sheets-Sheet l Gilbert J. Easley *EID ATTONEY May 17, 1960 G. J. EAsLl-:Y

CIRCUIT INTERRUPTER 3 Sheets-Sheet 2 Filed Sept. 24, 1957 Fig. 2.

May 17, 1960 G. J. EAsLEY 2,937,320

CIRCUIT INTERRUPTER Filed Sept. 24, 1957 3 Sheets-Sheet 5 Recloser United States Patent O kce 2,937,320 CIRCUIT INTERRUPTER Gilbert J. Easley, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application September 24, 1957, Serial No. 685,925

7 Claims. (Cl. 317-22) This invention relates to circuit interrupters and more particularly to circuit interrupters operated by duid pressure.

Some circuit breakers that are `designed for fluid presfsure operation are provided with tripping mechanisms that lare both trip-free and non-trip-free of the closing means. The trip device which `is vto function is usually selected according to the presence or absence of closing air pressure in the operating cylinder of lthe operating mechanism. 'When the circuit interrupter is standing in the closed posiition and fault current occurs there is no closing air in :the operating cylinder and the :non-trip-free tripping mechanism and goes to the'open position connected .to the closing means. In order to ob- :tain a quick iirst reclosure following a non-trip-free open-` .ing operation compressed fluid Vis admitted to the operating -cylinder approximately one-half cycle after the tripping Amagnet resets. Selecting means is usually kprovided tosc'- Ilect the tripfree tripping means upon admission Ofcom- ;pressed fluid to the operating cylinder so `that should the linterrupter close in against a Yfault xcurrent it will trip- :'free of the closing ithe reclosingY operations. In this situation the closing means is essentially in the closed position and no harm .'results. However, under certain conditions the tripping Vcurrent persists after the contactsseparate and after comg pressed uid is admitted to the operating cylinders. IIn ithis circumstance, the trip-free tripping mechanism` havfing been selected by admission of compressed fluid to the operating cylinder, the interrupter will vbe tripped free of the closing mechanism ,early Ain the closing operation and fthe closing mechanism will go to the closed position with- .out the restraint of the interrupter mechanism. This .causes heavy slamming yof the parts and results in serious .damage. This condition can be prevented by cutting off :the tripping current immediately after the tripping magnet 'functions to trip the breaker and before compressed fluid :is admitted to the operating cylinder to close .the inzterrupter.

object of the invention is to provide a circuit inter- :rupter `having trip-free and non-trip-free tripping mecha- :nisrn with means for quickly cutting oi the tripping Ycurarent following a tripping operation of the non-trip-free 'itripping mechanism.

Another object of the invention is to provide aV circuit :'interrupter embodying a tripping electromagnet with a erelay for cutting oit the tripping current to the tripping .imagnet immediately following a tripping operation.

'Another object of the invention is to provide a circuit iinterrupter having a tripping electromagnet with a relay 'A which has a slowerpickup time than the tripping electro- :magnet to cut off the tripping current ping magnet functions to trip the interruptor.

just after the trip- The invention both as to structure and operation, to-

;,gether with additional objects and advantages thereof, will be best understood from the following detailed description thereof when read in conjunction with drawings.

the accompanying breaker is tripped bythe 2,937,320 Patented May 17, 1960 admission of iluid pressure to the operating cylinder; and

Fig. 4 is a schematic diagram of the circuit for controll ling the operation of the interrupter mechanism.

, breaker operating rod 31 is operatively means when the contacts touch during l The invention is illustrated as applied to a circuit ini terrupter operating mechanism fully disclosed in R. C. Van Sickle Patent No. 2,65 6,430, issued October 20, 1953. Referring to Fig. 2 of the drawing, the circuit interrupter -11 which is illustrated diagrammatically, may be of any conventional construction and is adapted to be operated to the open position by means of an accelerating spring 13. The circuit interrupter is adapted to be operated to the closed position by means of an operating mechanism which in the embodiment illustrated is of the compressed uid type. The operating mechanism includes an operating cylinder 17 closed at its upper end by a plate 19 and `at -its lower end by a bottom plate 20 secured together by means'of bolts 21 (Fig. l). Mounted in the operating cylinder 17 (Fig. 2) is an operating piston 23 having secured thereto a piston rod 25 which is-slidable through a substantially air tight opening in the plate 19. A coupling 27 rigidly secured -to the upper end of the piston rod 2'5 is releasably connected to a coupling 29 secured to a breaker operating rod 31 by means of an inverted toggle comprising toggle links 33 and 35. The connected to the circuit breaker 11 by means of a suitable linkage.

T he toggle link 33 comprises a pair of spaced parallel links pivotally connected by means of a pivot pin 37 to the coupling 27. The toggle link 35 comprises a toggle link disposed between the links 33 and is pivotally connected to the coupling 29 by a pivot pin 39. The toggle links 33 and 35 are pivotally connected together by a knee pivot pin y4 1.

I n order to provide straight-linel movement of the operating rod 31 and thepiston rod 2'5 and to assist the tripfree toggle 33- 35 in maintaining the breaker closed, the pivotpins l37 and 39 are provided with rollers 43 and 44, respectively, there being a roller 43 mounted on each end of the pin 37 and a roller 44 mounted on each end of the pins 39. Thesey rollers cooperate with corresponding vertical slots 45 formed in a pair of spaced frame members 47 rigidly mounted on the plate 19 and extending upwardly therefrom in spaced parallel relation. To form The circuit breaker is held in the closed position by l a main latch* 51 (Fig. 2) and a light-load latch mechanismindicated generally at 53. The main latch 51 is pivotally mounted on a pin 55 supported in the frame members 47 and is biased by means of a spring-pressed plunger 57 into latching engagement with a latch inem- -ber 59 on the coupling 27. The plunger 57 is slidably mounted on a rod 58 mounted in a cross bar 61 supported between the frame members 47 and is biased by a compression spring 63. The main latch 51 has a latching surface 67 cooperating with the latch 59 on the coupling 27 and also has a projection 69 carrying a latch roller 70 which cooperates with the latch mechanism 53.

The light-load latch mechanism 53 includes an underset tripping toggle comprising toggle links 71 and 73, a trip-free trigger latch 75, cooperating to releasably maintain the tripping toggle in its underset position, and a non-trip-free latch 76 cooperating with the latch roller 70 on the main latch 51. The toggle link 71 comprises a pair of links rigidly joined by a cross member 77 and pivotally mounted on a xed pivot pin 79 supported in the frame 47. At their free ends the toggle links 71 between them carry a latch roller 81 with which the trigger latch 75 cooperates to maintain the tripping toggle 71-73 in its underset position. The toggle link 73 is pivotally connected on the knee pivot pin 41 of the tripfree toggle 33-35 and is pivotally connected to the toggle link 71 by a knee pivot pin 83.

The trip-free latch 75 and the non-trip-free latch 76 are pivoted on a pin 85 supported in a pair of brackets 86 and 87 (Fig. l) which are secured to a cross plate 89 mounted on the frame members 47. Mounted on the underside of the cross plate 89 (Fig. 2) is a tripping electromagnet 911 comprising a fixed magnet yoke 93, an energizing winding 95 and a movable armature 97. A trip rod 99 is secured to the armature 97 and extends upwardly through an opening in the magnet and through an opening in the plate 89, the upper end ofthe trip rod 99 being disposed beneath a latch selector 101.

A spring 103 compressed between the cross plate 89 and a spring guide 104 which is pivotally connected to the non-trip-free latch 76 biases this latch to latching position against a stop 106 mounted in the brackets 86 and 87. A similar spring (not shown) is provided to bias the trip-free latch 75 to latching position against a cross bar 105 disposed between the side members of the toggle link 71. The underset position of the tripping toggle 71-73 is adjustably determined by means of an adjusting screw 107 threadedly mounted in a cross bar 109 supported between the frames 47 and locked'in adjusted position by a lock nut 111.

A latch check switch 113 (Fig. 2) is provided for checking the position of the trip-free latch 75. The switch 113 is mounted on the cross plate 89 and the contacts of the switch are controlled by a plunger 115 which is engaged by an arm 119 of the trip-free latch 75 when the latch is in latching position.

The latch or trip selector bar 101 (Fig. l) is pivotally connected at its right-hand end to the upper end of a channel-shaped lever 121 by means of a pin 123. The lever 121 is pivotally mounted on a pin 127 supported on a bracket (not shown) secured to the adjacent frame member 47. The lever 121 is retained on the pin 127 by a 4nut 133 and a spring 135 biases the lever 121 in a counterclockwise direction to the position shown in Fig. l wherein a projection 137 on the left-hand end of the selector bar 101 is positioned beneath a tail portion 139 of the non-trip-free latch 76 and a second projection 141 on the selector bar 101 is positioned out of alignment with and to the left of the arm 119 ofthe trip-free latch 75. The selector bar '101 extends through and is guided by a slot in the bracket 87 (Fig. 1).

With the selector bar 101 in the position shown in Fig. 1, operation of the tripping 'magnet 91 causes the trip rod 99 to move upwardly engaging and moving the selector bar upwardly. Since the projection 137' on the selector bar`101. is, at this time, positioned vbeneath the tail 139 of the non-trip-free latch 76, this latch will be actuated to trip the breaker and the breaker will go to the open position without disconnecting the breaker mechanism from the operatingfpiston 23. However, if the selector bar 101 is shifted to the right (Fig. 1) by means and under conditions to be described hereinafter, the projection .137 will be moved out from under the tail 139 of the non-trip-free latch 76 andthe projection 141 will be positioned beneath the arm 1,19 of the trip-free latch 75. Consequently, operation of the trip magnet 91 with the selector bar 101 in this` position will actuate the trip-free latch and trip the breaker free ofthe closing means.

Referring to Fig. 2 of the drawing, in the closed position of the breaker, the latch 51, which is held in latching position by the non-trip-free latch 76 holds thel piston 213 in the closed position, in which it is shown, against the force exerted by the accelerating spring 13 and the force of a spring 147 compressed between the bottom of the piston 23 and a disc 149. The disc 149 is suitably secured to a cylindrical member 151 which has secured thereto a ring 153 supported on certain of the bolts 21 that fasten the bottom plate 20 of the operating cylinder in place. The latch 51 is of the slip-off type, that is, the latch 51 is so constructed and arranged with respect to the latch member 59 that it will not itself hold the piston rod 25 in the closed position against the -biasing force of the spring 147. The relative positions of the parts are such that the upward thrust of the spring 147 applies a small component of the force through the latch roller 70 to the non-trip-free latch 76.

The accelerating spring 13 applies an upward force on the breaker operating rod 31, and, since the pivot pins 37 and 39 are constrained by the slots 45 to move in a straight line, a small component of the force of the spring 13 is applied through the link 35 to the tripping toggle '7l-73. Due to the tripping toggle being only slightly underset, a very small component of the force of the accelerating spring 13 is applied through the tripping toggle 71-73 and the latch roller 81 to the tripfree latch 75.

Assuming the breaker to be in the closed position, it is tripped open by the non-trip-free latch means in the following manner:

When the tripping magnet 91 is energized from a suitable source, the armature 97 moves upward to engage and move the selector bar 101 upward. This movement of the selector bar 101 causes the projection 137 thereon to engage the tail 139 and actuate the non-trip-free latch 76 counterclockwise (Fig. 2) to unlatching position. This frees the latch 51 and the accelerating spring 13, together with the spring 147, moves the latch 51 to unlatching position and operates the breaker to open position. During the non-trip-free opening movement, the main toggle 33-35 is held in thrust transmitting position by the toggle link 73 which, due to the fact that the toggle link 71 is held in the position shown, moves clockwise about the pin S3 as a iixed pivot. The result is that the breaker operating rod 31 and the piston rod 25 move upwardly as a unit, the breaker going to the open position and the piston 23 being moved to the upper end of the cylinder 17.

The circuit breaker is closed by admitting compressed fluid to the operating cylinder 17 above the piston 23 which forces the piston downwardly, drawing the toggle link 33 therewith. Since the toggle link 7.1 of the tripping toggle is held in the position shown in Fig. 2 by the trip-free latch 75, the link '73 again pivots about the pivot pin S3 which acts as a iXed pivot, thereby holding the main toggle 33-35 in thrust transmitting position during the closing operation. The closing force applied to the link 33 is, therefore transmitted through the link 35 to move the breaker rod 31 downwardly and close the breaker.

Under certain conditions, to be described later, the lever 121 (Fig. 1) is rotated clockwise about its pivot and draws the latch selector bar 101 to the right. This moves the projection 137 from beneath the tail l139 of the non-trip-free latch 76 and positions the projection 141 beneath the arm 119 of the trip-free latch 75. Operation of the tripping magnet 91 now causes the projection 141 to engage the arm 119 (Fig. 2) and actuate the tripree latch to unlatching position. This releases the underset tripping toggle 71-73 and the force of the accelerating spring 13 applied to the tripping toggle causes collapse of this toggle and permits collapse of the main toggle 33-35 When this occurs the breaker operating rod 31 moves upwardly free ofl the piston 23 to open the breaker free of the closing means.

` latching position.

In order to restore the main toggle 33-35 to thrust transmitting position to thereby recouple the breaker to the closing means, it is necessary to release the latch 51 which permits the spring 147 to move the piston 23 and the piston rod upwardly. This is effected by a projection 155 on the trip-free latch 75 which, after a predetermined movement of the trip-free latch in unlatching direction, engages and moves the non-trip-free latch 76 to its un- The spring 147 now forces the latch 51 to unlatching position and moves the piston 23 and the piston rod 25 upwardly. The pivots 37 and 39 being constrained to travel in a straight line by the slots 45, the

upward movement of the toggle link 33 will cause the link 35 to rotate counterclockwise about the pivot 39 to the normal inverted or thrust transmitting position of the toggle 33--35. This action, through the knee pin 41 and the link 73 moves the link 71 about its pivot '79 far enough to permit reengagement of the trip-free latch 75 under the latch roller 81. This restores the main toggle to thrust transmitting position thereby recoupling the piston rod 25 to the breaker operating rod 31 in preparation for `a closing operation.

Compressed gas is admitted to the cylinder 17 to close the circuit breaker Iby means of an inlet valve device indicated generally at 161 (Figs. l and 3). 'I'he inlet valve device comprises a main housing 163 secured by bolts 165 to the top o-f the upper plate 19, which closes the upper end of the cylinder. The housing 163 has a cylinder 167 formed therein which is closed at -its upper end by a member 168 secured thereto by bolts 185 and in which is disposed a valve operating piston 169. A valve rod 171 having a valve element 173 secured to its lower end extends upwardly'through a guide bearing 175 into the cylinder 167 and cooperates with the piston V169. The valve element 173 is secured to the rod 171 by a nut 177 and the valve is biased to closed position by a spring 179 compressed between a closure plate 181 and the valve element 173.

A high pressure chamber y187 in the housing 163 below the valve 173 .is supplied with fluid under pressure from a suitable source by means of a pipe 189. An inlet port 191 above the valve 173 communicates with the operating cylinder. The inlet valve 173 is operated to open position by admitting Huid pressure from the high-pressure chamber 187 to the cylinder 167 above the piston 169 which forces the piston downwardly in the cylinder 167 and moves the valve 173 to the open position.

Fluid pressure is admitted to the cylinder 167 by means of a magnetically operated pilot valve device indicated generally at 195 (Figs. 1 and 3). The pilot valve device comprises a housing 197 secured to the housing 163 of the inlet valve device. The housing 197 is provided with a chamber 201 communicating with the highpressure chamber 187. A valve 203 normally closes off the chamber 201 from a passage 205 communicating with the cylinder v167 above the piston 169. The valve 203 is in biased closed position by a spring and is secured on a rod 207 which is attached to the armature (not shown) of an electromagnet 209. Also attached to the rod 207 is a normally open exhaust valve 211 which closes upon opening of the valve 203 to close a passage communicating the passage 205 to atmosphere.

Formed in the housing 163 is a cylinder 213 in which is disposed a cup-shaped exhaust valve 215 for controlling a large exhaust port 217. The valve 215 has a reduced portion 219 disposed in a cylinder 221 which communicates by means of a passage 223 with the cylinder 167 and the passage 205. The cylinder 213 above the valve 215v is normally atatmospheric pressure by means of one or more holes inthe valve. The exhaust valve 215. is.y normally biased by gravity or a suitable spring (not shown) to the closed position where it is seated on a beveled annular Valve seat 225 secured to the housing 163 by means of a flange' and bolt 227. A chamber 229 surrounding the valve seat 225 and the lower portion of the valve 215 communicates with the cylinder 17 by suitable large passage means (not shown).

When the electromagnet 209 is energized, the rod' 207 is moved downward closing the exhaust valve 211 and opening the valve 203, thereby admitting fluid pressure from the high pressure chamber 187 through the passage 205 to the cylinder 167 above the piston 169. The fluid pressure forces the piston 169 down moving the rod 171 and the inlet valve 173 to open position thereby admitting iluid under pressure through the inlet port 191 to the operating cylinder 17 to close the breaker in the previously described manner.

At the same time the compressed fluid is admitted to the cylinder 167 to open the inlet valve 173 iluid pressure is also admitted through the passage 223 to the cylinder 221 above the portions 219 of the exhaust valve 215 in order to maintain the exhaust valve closed' during the closing operation.

When the electromagnet 209 is deenergized at the end of the closing operation, the valve 203 closes and the valve 211 opens to vent the high pressure iluid from the cylinder 167 to permit the spring 179 to close the inlet valve 173. At the same time, the high pressure iiuid is vented from the cylinder 221 through the passages 223 and 205 whereupon the closing charge of high pressure fluid in the operating cylinder 17 and in the chamber 187 blasts the exhaust valve 215-open to dump the compressed iluid from the operating cylinder. As soon as the closing charge of compressed fluid is exhausted from the operating cylinder, the exhaust valve 215 is restored to its closed position.

When the breaker arrives at its fully closed position, the spring 63 (Fig. 2) moves the latch 51 into engagement with the latch member 59 on the coupling 27 to hold the mechanism and the breaker in the closed position.

If there is no fault condition such as an overload or a short-circuit current in the main circuit at the time the contacts are closed, the circuit breaker will be latched in the closed position. However, if the breaker closes in against a fault current, Vthe trip device 91 will function and trip the breaker free of the closing means by actuating the tripfree latch 75. j

It was set forth previously that under certain conditions the lever 121 (Fig. l) is rotated clockwise from the position shown to withdraw the projection 137 from beneath the tail 139 of the non-trip-free latch 76 and position the projection 141 of the latch selector bar 101 beneath the arm 119 of the trip-free latch 75 in order to effect trip-free tripping of the breaker. This is effected by a small cylinder 233 (Figs. 1 and 3) in the valve housing 163 and a piston 235 disposed for movement therein. A passage 237 (Fig. 3) communicates the cylinder back of the piston 235 with the inlet port 191. A rod 239 attached to the piston 235 extends out through an opening in a nipple 241 in the end of the cylinder 233. The outer end of the rod 239 is disposed adjacent the lower end of the lever 121 and the spring 135 which normally maintains the lever121 and the selector bar 101 in the position shown also acts through the lever 121 and rod 239 to hold the piston at the inner end of the cylinder 233.

When the inlet pressure through the inlet port 191 to the operating cylinder to close the breaker, fluid pressure is admitted through the passage 237 (Fig. 3) to the cylinder 233 and moves the piston 235 toward the left (Fig. l). This movement of the piston 235 thrusts the rod 239 outwardly and rotates the lever 121 clockwise to position the latch selector bar 101 for operating the trip-free latch 75 as previously set forth. In this manner, the tripfree latch is selected whenever the breaker closes against a fault condition with the charge of high pressure fluid in the operating cylinder 17.

When the inlet valve 173 closes and the exhaust valve 215 `opens to dump the closing air from the operating valve 173 is operated to admit uid cylinder, the bias of the spring 135 restores the lever. 121 and the selector bar 101 to the position shown and moves ihepiston 235 to the inner end of the cylinder 233.

When the breaker closes against a fault condition and trips free of the closing means, as previously described, it is necessary to wait for the closing air above the piston 23 to exhaust to near atmospheric pressure before the spring 147 can move the piston 23 and the piston rod 25 upwardly to recouple the piston rod 25 to the breaker rod 31 and to reengage the trip-free latch 75. In order to assist the spring 147 and increase the speed of the recoupiing or retrieving action, means is provided for admitting compressed iluid to the cylinder 17 below the piston 23. This means comprises an electroniagnetically operated valvev device indicated generally at 243 (Fig. 2). The valve device comprises a cylinder 245 having piston 247 thereon biased by a spring '249 to a position where it normally closes an inlet passage 251 communicating with the operating .cylinder 17 below the piston 23. An exhaust passage 253'also communicates the cylinder 17 to the valve vcylinder 245 below the valve 247. An electro magnet 255 is mounted on top of the cylinder 245 and the armature (not shown) is connected by a rod 257 to the valve 247. When the magnet 255 is energized it moves the piston 247 downwardly opening the inlet passage 251 and closing the exhaust passage 253. When the magnet 255 is deenergized the spring 249 moves the valve 247 upwardly to close the inlet passage 251 and open the exhaust passage 253.

Referring now to Fig. 4 of the drawing, grammatically shows the circuitry for controlling the inlet valve electromagnet 209, the tripping electronlagnet 91 and the electromagnet 255, the winding of the electromagnet 269, which controls the admission of uid pressure to the operating cylinder 17 for closing the breaker, is connected in an energizing circuit extending from a supply line 267 through a conductor 269, contacts 271 oi a release relay 273, coil of the magnet 209, a conductor 279 and through contacts 281 of a closing relay 283 to a supply line 285.

The energizing winding of the closing relay 283 is connected in a circuit extending from the supply line 267, conductors 286 and 287, back contacts 289 of the release relay 273, the winding of the closing relay 283, contacts 234 of the latch check switch 113, a conductor 291 and through the contacts of a manual closing switch 293 to the supply line 285.

The winding of the release relay 273 Yis connected in a circuit extending from the supply line 267, 'a conductor 395, auxiliary contacts 297 on thebreaker operating mechanism, adapted to be closed when the breaker reaches closed position, winding of the release relay 273, conductor 299, contacts 361 of the closing relay 283 and a conductor 303 to line 285.

A stick circuit is provided for maintaining the closing relay 283 energized following a momentary operation of the manual closing switch 293. This circuit extends from line 267, conductors 286 and 287, contacts 289 of the release relay 273, the winding of the closing relay 283, conductor 365, contacts 301 of the closing relay 283 and conductor 393 to the line 285. A stick circuit is also provided for maintaining the release relay 273 energized until the manual closing switch 293is released. This holding circuit extends from the line 267 over conductors 286, contacts 307 of the release relay 273, coil of the release relay, conductors 299 and 395, contacts 25:4 of the latch check switch 113, conductors 291 and the contacts of the manual closing switch 293 to the line 285.

The circuit for energizing the tripping electromagnet 91 extends from the line 267, contacts 309 of s fault responsive relay 311, conductor 313, auxiliary contacts 315 on the breaker mechanism, conductor 317,` coil 95 of the tripping magnet, contacts 318 of a trip cut-off relay 3,22, and a conductor l319 to the line 285. A manual opening switch 320 is connected in the circuit in: parallel which aiarelation with the contacts 309' of the fault relay to etect manual opening'of the breaker.

Operation of the 'fault relay 311 closes the contacts 309 to elfect energization of the trip magnet 91 over the previously described circuit. If the breaker has been standing in the closed position and there is no compressed air in the operating cylinder 17, the projection 137 on the selector bar 101 is in line with the non-trip-free latch 76 and the breaker will be tripped open non-trip free of the closing means.

The circuit breaker is closed from the full open position by momentary closure of the manual closing switch 293. Closure of this switch effects energization of the closing relay 283 over the circuit from line 267, conductors 236 and 237, back contacts 289 of the release relay 273, coil of the 'closing relay 233, contacts 284 of the latch check switch, conductors 291 and the contacts of the manualclosing switch 293 to thisline 235. Energization of the closing relay '283 closes its contacts 231 to effect energization of the inlet valve magnet 299 over the circuit from line 267, conductor 269, back contacts 271 of the release relay 273, coil of the inlet valve magnet 209, conductors 279 and the contacts 281 of the closing relay to line 285. Operation of the closing relay 283 closes its contacts 301 to set up its holding circuit and also prepares the circuit to energize the release relay upon closing of the auxiliary contacts 297, and opens the contacts 271 and 289 which respectively drop out the inlet valve magnet 269 and opens the circuit through the winding ofthe closing relay 283. Deenergization of the closing relay 283 effects opening of its contacts 301 and drops out the release relay 273. 'Ille circuit breaker now in the closed position with the parts in their normal conditions. lf there is no fault condition present when the breaker is closed, the mechanism will be relatchcd and the breaker will remain in the closed position.

The closing operation of the circuit breaker may bc initiated automatically by means of a recloser indicated generally at 321 (Fig. 4) following an opening operation. The recloser 321 is of a well known type which automatically effects a single high speed reclosing operation following a non-trip-free opening operation which is fol-- iowed by one or more quick reclosing operations when the breaker open trip-free of the closing means. A manually operable switch 323 is provided to elfect encrgization of the recloser 321, or to prevent automatic reclosing if it is not desired.

Assuming that the switch 323 is closed7 the automatic reclosiug operation is effected by the recloser 321 which upon closure of auxiliary contacts 327 momentarily close; a circuit for energizing the closing relay 283. This circuit extends from line 285, switch 323, recloser 321, conductor 325, auxiliary contacts 327 on the breaker operating mechanism closed during the opening operation, conductor 329, contacts 284 of the latch check switch 113, coil of the closing relay 283, contacts 289 of the release relay 273, and conductors 287 and 286 to line 267. .This energizes the closing relay 283 which closes its contacts 281 to energize the inlet valve magnet 209 and the closing operation is thereafter effected in the previously described manner.

When the breaker is tripped by the non-trip-free latch 76 it is necessary to admit the closing air pressure to the operating cylinder 17 very early in the opening stroke of the breaker in order to obtain very high speed reclosing on the first reclosure. Admission of compressed air to the operating cylinder, as previously set forth, immediately prepares the trip mechanism for a trip-free operation. The trip circuit is made up by the auxiliary contacts l315 on the interrupter mechanism which close before the -interrupter contacts touch and, consequently, open during an opening operation after the interruptor contacts open. It sometimes happens that the trip circuit is not interrupted soo'n enough and the trip circuit remains energized Jwhen the tripfree tripmeansis selected. In this' circumstance, with the breaker open and the piston 23 at the top of the cylinder 17, the breaker will trip-free of the closing means without reclosing and the piston will be driven at excessively high speed to the closed positio'n without the restraint of the breaker mechanism which can cause serious damage. To prevent this the trip cut-off relay 322 is provided. The coil of the relay '322 is connected in the trip circuit in parallel relation with the coil of the tripping magnet 91 and the contacts 318 of the relay 322 are connected in series relation with the coil 95 of the tripping magnet. Since the coils o'f the tripping magnet and the trip cut-olf relay are in parallel, they will be energized at the same time. The tripping magnet 91 picks up and completes the tripping operation in approximately one-half cycle of sixty cycles alternating current but does not drop out for a full cycle later, whereas the trip cut-olf relay 322 is selected with a pickup time of 3%: cycle and cuts oi the tripping current Yan instant after the trip magnet 91 has completed its tripping function. This makes possible the admissio'n of compressed uid to the operating cylinder earlier in the opening strokev and results in a quicker first reclosure of the breaker.

If, during the iirst reclosure, the breaker closes in against a fault condition the closing fluid is in the cylinder 17 and the breaker will be tripped open by the tripfree latch 75 and the breaker will open free of the closing mechanism. However, recouplng the piston 23 with the breaker Amechanism must wait for the closing air to' be dumped from the cylinder 17 which does not occur until the inlet valve magnet is deenergized. This is effected by energization of the release relay 273 upon closure of the auxiliary contacts 297 near the end of the closing operation. The valve device 243 (Figs. 2 and 4) is provided to admit co'mpressed air to the cylinder 17 below the pistonA 23 to accelerate the speed of the retrieving movement of the piston. The coil of the valve magnet 255 (Fig. 4) is connected in the circuit to be energized simultaneously with the energization of the tripping magnet 91. The circuit extendsfrom the line 267, contacts 309 of the fault relay 311, conducto'r 313, auxiliary contacts 315, conductor 317, a conductor 331, coil of the valve magnet 255, conductor 333, contacts 335 of a pressure responsive relay 337 and conductors 339 and 319 to the line 285. The pressure relay 337 is arranged so that its contacts 335 are open when the air in the cylinder 17 is at atmospheric pressure and closed while there is compressed air in the cylinder.

When the breaker closes in against a fault condition the fault relay 311 closes its contacts 309 immediately energizing the trip magnet91, the trip cut-off relay 322 and the magnet255 ofthe valve device 243. The valve device 243 functions to close the exhaust passage 253 (Fig. 2) and open the inlet passage 251 to admit a charge of co'mpressed air to the cylinder 17 below the piston 23 even though the pressure of the closing charge of compressed air above the piston has not fallen to atmospheric pressure. The retrieving air pressure admitted below the piston 23 together with the spring 147 eiects high speed recouplng of the closing means to the breaker mechanism and resetting o'f the trip-free latch 75.

When the valve magnet 255 is energized it closes contacts 341 to seal itself in around the pressure relay contacts 335.

It is necessary to deenergize the valve magnet 255 and permit the spring 249 (Fig. 2) to close the inlet passage 251 and open the exhaust passage 253 to vent the retrieving air below` the piston after the piston has accelerated in retrieving directions. This is effected by the auxiliary contacts 315 (Fig. 4) which are in the trip circuit. It is to be noted that the valve device 243 functions to' admit retrieving air below the piston 23 only when there is closing air in the cylinder 17 above the piston and the breaker is tripped free of the piston so that compressed air is not lost on non-trip-free tripping 10 operation since there is no air under pressure in the cylinder 17 at this time. x

Having described the invention in accordance with the provisions of the patent statutes, it is to be understood that various changes and modifications may be made in the structural details thereof without departing from the spirit of the invention.

I claim as my invention:

l. An automatic reclosing circuit interrupter including a control circuit, operating mechanism for said interrupter, power means for closing said interrupter, tripfree tripping means and non-trip-free tripping means normally releasably restraining said operating mechanism in closed position and selectively operable to effect opening of said interrupter, electromagnetic means operable when energized to actuate thev selected tripping means, electroresponsive means operable when energized to' effect energization of said power means, trip selector means operable in response to the energized condition of said power means to select which of said tripping means is to be actuated to' trip said interrupter, said trip selector means when said power means is deenergized being positioned to select the non-trip-free tripping means and being moved to a position to select the trip-free tripping means by energization of said power means, a relay connected in said circuit to be energized simultaneously with said tripping eIectromagnet, contacts operable by said relay to deenergize said tripping electromagnet after a non-trip-free tripping operation to prevent actuation of said trip-free tripping means after said power means is energized to close the interrupter following a non-tripfree tripping operation.

2. An automatic reclosing circuit interrupter including a control circuit, operating mechanism for said interrupter, fluid pressure operating means for closing said interrupter, electroresponsive means operable when energized to admit uid pressure to said operating means, trip-free tripping means and non-trip-free tripping means normally releasably restraining said operating mechanism in'closed position and selectively operablel to effect opening of said interrupter, electromagnetic means operable when energized to actuate the selected tripping means, trip selector means operable in response to the fluid pressure in said fluid pressure means to select the tripping means to be actuated, said trip selector means normally being positioned to select the non-trip-free tripping and being moved to a position to select the trip-free tripping means by admission of iiuid pressure to said fluid pressure operating means,'a relay connected in said circuit and energized simultaneously with the energization of said tripping electromagnet, contact means operable by said relay and connected to effect deenergization of said tripping electromagnet after a non-trip-free tripping operation to prevent operation of said trip-free tripping means after uid pressure is admitted to said fluid pressure operated means to close said interrupter following a non-trip-free tripping operation.

3. An automatic reclosing circuit interrupter, operating mechanism for said interrupter, uid pressure closing means comprising an operating cylinder and a piston movable therein to close said interrupter, electro-responsive means operable when energized to admit fluid pressure to said cylinder on one side of said piston to close said interrupter, trip-free tripping means and non-tripfree tripping means normally releasably restraining said operating mechanism in closed position and selectively operable to eiect opening of said interrupter, trip selector means operable in response to admission of fluid pressure tio said cylinder to select said trip-free tripping means, said tripfree tripping means being operable when said interrupter closes against a fault condition to trip said operating mechanism free of said closing means, and auxiliary electroresponsive means operable when energized to admit uid pressure to said cylinder on the other side of said :1T piston to tect'hgn' speedvrecouplingof-said closing means to said breaker operating means.

4. An automatic reclosing circuit interrupter, operating 'mechanism for said interrupter, uid pressure closing means comprising an operating cylinder` and a piston movable therein to close said interrupter, electroresponsive means operable when energized to admit uid pressure to said cylinder on one side of said piston to close said interrupter, trip-free tripping means and non-trip-free tripping means normally releasably restraining said operating mechanism in closed position and selectively operable to etect opening of said interrupter, trip selector means operable in response to admission of uid pressure to said cylinder to select said trip-free tripping means, said tripfree tripping means being operable when said interrupter closes against a fault condition to trip said operating mechanism free of said closing means, auxiliary electroresponsive means operable'when energized to admit fluid pressure to said cylinder on the other side of said piston to effect high speed recoupling of said closing means to said breaker means, means responsive to the absenceof closing iluid pressure in said cylinder to actuate said trip selector means to select said non-trip tripping means, and pressure responsive relay means operable when said nontrip-free tripping means is selected to prevent energization of said auxiliary electroresponsive means.

5. An automatic reclosing circuit interrupter, operating mechanism for said interrupter, vtluid pressure closing means for said interrupter including a movable piston subject to opposing uid pressure in a high pressure chamber and a low pressure chamber, electroresponsive means operable when energized to admit iluid pressure to said high pressure chamber to close said interrupter, trip-free tripping means and non-trip-free tripping means normally restraining said operating mechanism in closed position and selectively operable to eiect opening of said interrupter, trip selector means responsive to the uid pressure condition in said high pressure chamber to select which of said tripping means is to be operated to trip saidinterrupter, said trip selector being normally positioned to select said non-trip-free tripping means and being moved to a position to select said trip-free tripping means by iiuid pressure admitted to said high pressure 'chamber to close said interrupter, tripping'electromagnetic means operable in response to a fault condition to actuate the selected tripping means, a relay connected to be energized simultaneously `with energization of said tripping Yelectromagnetic means and operable'when energized `to deenergize said trippingelectromagnet following a non-trip-free-trippng operation to prevent operation of said trip-free tripping 50 means after fluid pressure 1sl admitted to said high pressure chamber to close said interrupter following a nontrip-frce--trippingoperation, auxiliary fluid pressure -re-. sponsive means operable to admit fiuid pressure to said low pressure chamber, a fluid pressure responsive relay operableby-uid pressure admitted to said high-pressure chamber on a close-open operation to etect energization of said auxiliary electroresponsive means to admit uid pressureto said low pressure chamber following a tripfree tripping operation to effect high speed recoupling of said closing means to said operating mechanism.

6. An automatic reclosing circuit interrupter including a control circuit, power means for closing said interrupter, trip-free tripping means and non-trip-free tripping means selectively operable to effect opening of said interrupter, electromagnetic trip means operablewhen energized to actuate the selected tripping means, electroresponsive means operable when energized to etect energization of said power means, trip selector means positione'dto select the non-trip-free tripping means when said power means is deenergized and moving to aV position to select the trip-free tripping lmeans byy energization of said power means, a relay connected in saidl circuit in parallel relation with said electromagnetic trip means to be energized simultaneously therewith, and contacts operated by said relay to'etect deenergization of said electromagnetic trip means after said electromagnetic trip means has tripped said vinterrupter and before said power means is energized.

7. An automatic reclosing circuit interrupter including a control. circuit, power means for closing said interrupter, trip-free tripping means and non-trip-free tripping means selectively operable to effect opening of said interrupter, electromagnetic trip means operable-when energized to actuate the selected tripping means, electroresponsi'vc means operable when energized to eifect energization of `said power means, trip selector means positioned to select the non-trip-free tripping means when said power means is deenergized and moving to a position to select the trip-free tripping means by energization of said power means, a relay connected in said circuit in parallel relation with said electromagnetic trip'means to be energized'simultaneously with the energization of said electromagnetic trip means, and contact means operable by said relay to effect deenergization of said electro- :lagnetic trip means after said electromagnetic trip means has tripped said interrupter and before said power means is energized.

References Cited in the file of this patent 'UNITED STATES PATENTS

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