US1966218A - Electrical switch gear - Google Patents

Description

July 10, 1934. J. H. POWERS ELECTRICAL SWITCH GEAR Filed Aug. 21, 1929 79 Inventor James f-LPowers,

HLS Attobne designs are well known Patented July 10, 1934 ELECTRICAL SWITCH GEAR James H. Powers, Yeadon, Pa., assignor to General Electric Company, a corporation of New York Application August 21, 1929, Serial No. 387,522 9 Claims. (Cl. 175298) My invention'relates to electrical switchgear, and more particularly to a housing and mounting structure of the cubicle type for circuit breakers and accessory apparatus, wherein the circuit breaker remains stationary during the disconnecting and isolating operations thereof.

In switchgear of the type comprising a circuit breaker of appreciable interrupting capacity, as of the oil-break type, for example, and accessory equipment such as panels, disconnecting switches, current and potentialtransformers, bus bars, etc., arranged within a compartment or cell, it has generally been the prior practice to employ one of two types of design, depending on the particular requirements of the installation. These in the art and comprise the truck-type panelequipment and the metalclad type.

In the truck-type of equipment, the oil circuit breaker is mounted upon a specially built truck and is adapted to be moved or rolled into or out of the compartment or cell under predeter mined conditions. The movable contacts of the disconnecting device for the circuit breaker generally are laterally mounted upon the breaker,

the stationary contacts being at the rear of the,

compartment, that bodily movement of the breaker itself is required to effect operation of the disconnects. Moreover,the instrument panel, which is likewise mounted upon and carried by the truck may be inspected at the rear thereof only by withdrawing the truck, including, of course, the circuit breaker, from the compartment, thereby requiring complete interruption of service with regard to that particular 'circuit breaker. Even if a spare truck is available so that service may be continued during inspection of the first-named truck-panel, temporary interruption of service cannot well be avoided. The arrangement above described must of necessity be quite massive and occupy considerable space due to horizontal movement of the truck in opening the disconnects.

The metal-clad type of equipment on the other hand is mounted within the compartment, or frame thereof, the upper part of which contains the stationary equipment, as bus bars, disconnecting switches, etc. In this type of design,

the movable disconnecting contacts of the circuit breaker are likewise mounted upon the breaker,

. the coacting stationary contacts being disposed above the breaker, so that instead of horizontal movement, as in the case of the truck-type design, the breaker moves vertically to connect and disconnect the aforesaid contacts. This bodily vertical movement of the comparatively massive circuit breaker is effected by more or less elaborate hoisting mechanism, depending on the weight of the circuit breaker. The instrument panel for this type of design is generally mounted in front of the circuit breaker and spaced therefrom so that removal of the breaker may be accomplished without disturbing the panel. This feature necessitates generous floor space due to the fact that the circuit breaker is first moved outwardly towards the panel, and then in a direction at right angles thereto in order to clear the panel. In both the truck and metal-clad types, the movement of the circuit breaker generally effects an isolating operation, by' means of movable shutters or the like.

Accordingly, it will be noted with regard to the above discussed designs that in each case bodily movement of the circuit breaker itself is necessary in order to effect the disconnecting operation and final electrical isolation of the breaker with respect to the equipment associated therewith.

A principal object of my invention is the provision of switchgear comprising a cubicle within which a circuit breaker is mounted, wherein the circuit breaker may be disconnected and electrically isolated from its accessory equipment by an individual operation distinct from and independent of movement of the circuit breaker with respect to the cubicle.

A further object is the provision of switchgear oi the character above described arranged within a compartment or cell, wherein the operation effecting disconnection and isolation of the circuit breaker is performed exteriorily of the circuit breaker compartment without necessitating change in the position of said breaker.

A further object is the isolation of the circuit breaker itself with respect to the front portion of the compartment whereby the outer door of the compartment may be utilized as aninstrument panel, inspection of which may be had without interrupting the service of the circuit breaker.

A further object is the provision of a mounting structure for the circuit breaker wherein a single truck unit, orequivalent, may be used for moving a plurality of breakers into or from their respective compartments; and more particularly, wherein the circuit breaker rests upon a station- 105 ary structure spaced .a predetermined distance from the floor of the compartment A further object'is the provision of apparatus of the character above described which shall occupy a comparatively small amount of floor space 110 with the passage 50. at the rear of the cubicle.

and be less massive than similar apparatus heretofore used.

Other objects and advantages will appear from the following description taken in connection with the accompanying drawing.

Referring to the drawing, Fig. 1 is an elevational cross-sectional view of switchgear embodying my invention; Fig. 2 is an elevational front view of the structure illustrated in Fig. l, partly in section; Fig. 3 is a detailed view of structure illustrated in Fig. 1 in another position; a d Fig. 4 is a diagrammatic illustration of circui connections.

In Fig. 1 there is shown switch housing and mounting structure of the cubicle type comprising a cell-like structure. The rear wall of the housing comprises removable sections, 1 and 2, and a fixed section 3. Spaced from section 3 is another removable section, 4, forming, together with an associated section, 5, a conduit compartment or passage;5a, at the rear of the housing. The top section, 6, and a front section, '7, forming a super structure, are likewise removable for the purpose of permitting access to the interior, as will be hereinafter described. The lower front section comprises a hinged door or panel, 8, upon which may be mounted instruments and meters as in the case of the usual instrument panel. For the purpose of simplicity of the drawing, no instruments are shown mounted upon the door panel 8, it of course being understood that the instruments may be readily mounted upon the outer face of the panel in the usual manner, the wiring, etc., being disposed along the inner side thereof.

The housing structure, or cubicle, as it will be hereinafter referred to, is divided by partitions or barriers 9, 10 and 11 into compartments, the

lower compartment comprising the circuit breaker compartment within which is disposed an oil circuit breaker 12, supported upon a tray 13, having side supports 13a, as channel members, resting upon the floor of the compartment. The circuit breaker 12 may be of conventional design with the exception of its disconnecting switching structure hereinafter described, and is provided with the usual breathing pipe 14 communicating An emergency vent 16 likewise communicates with the passage 5a which may exhaust in any suitable manner through the lower part or floor of the cubicle. A- member 18 secured to tray 13 has mounted thereon an upright member 19 to which is secured a yoke-like member 20 for supporting the circuit breaker. With the circuit breaker unit in the position shown, a combined mechanism bracket and steel protective diaphragm 21 which is secured to upright 19 forms a front wall of the circuit breaker compartment. Diaphragm 21 is therefore normally spaced an appreciable distance from panel 8 forming therewith an operating compartment. Upon the outer face of diaphragm 21 and within the operating compartment is mounted the usual operating mechanism 22 for the circuit breaker, operative connection therewith being had through an aperture 23 in the protective diaphragm. Mounted upon the top of circuit breaker 12 are stationary contact studs 24 and 25 comprising the stationary contact members of the disconnecting devices for the circuit breaker. As illustrated in Fig. 1, contacts 24 and 25 are engaged by their cooperating movable contacts 26 and 27, whose operation will be presently described.

The partition 11 forming the top of the circuit operating mechanism.

breaker compartment comprises a compound barrier of. suitable insulating material-and is provided with apertures 28 and 29 disposed in alignment with the longitudinal axes of the movable contacts 27 and 26, respectively. A movable shutter or isolating member 30 of suitable insulating material is mounted for reciprocal movement with respect to barrier 11 and is likewise provided with apertures 31 and 32 adapated to be in alignment under predetermined conditions with apertures 28 and 29.

As illustrated, the circuit breaker is in its closed position with the movable disconnecting contacts 26 and 27 extending through the aligned apertures in shutter 30 and barrier 11 to engage the respective stationary contacts carried by the breaker. Since it is requisite that the main circuit breaker be open before the disconnecting contacts are open, it is necessary to provide interlocking means between the main switch operating mechanism and the disconnecting mechanism. It is also desirable that after the disconnecting contacts are separated there shall be an insulating barrier interposed between the stationary and movable contacts. To accomplish these purposes there is provided means for raising contacts 26 and 27 through the apertures in the barrier and shutter into the compartment formed by partitions 10 and 11, hereinafter referred to as the disconnecting switch compartment. The above operation is of course permitted only after opening of the main circuit breaker, thereby rendering the interlocking means ineffective. The operation of raising the movable contacts 26 and 2'7 into the disconnecting switch compartment also effects translational movement of shutter 30 so that it takes the position illustrated in Fig. 3 wherein apertures 28 and 29 are closed by the shutter thereby interposing an isolating and insulating barrier between the stationary and movable contacts of the disconnecting device.

The operating means to effect disconnection and isolation of the circuit breaker in the manner above described comprises a hand wheel 33 or equivalent operating mechanism, disposed in the aforesaid operating compartment, having a worm connection with a toggle operating member 34 arranged so that rotation of wheel 33 imparts longitudinal movement to member 34. The shaft of wheel 33 has mounted thereon a notched disc,

35, for coacting with a pawl 36'pivoted at 36a, which in turn is controlled by the main switch operating mechanism. Pawl 36 is normally biased by spring 37 in clockwise direction to engage one of the notches of disc.35 and thereby restrain wheel 33 from rotative movement. The lower arm of pawl 36 is connected to a rod 38 guided ,for reciprocal movement and provided with a lug 39 depending through an aperture in barrier 11 into the path of a pivoted latch actuator member 40 having a depending portion 41 likewise in the path of movement of a'pivoted member 42 forming part of the circuit breaker Referring to Fig. 3, it will be noted that when the main circuit breaker is tripped to open position, link 42 in moving counter-clockwise engages the depending portion 41 of latch actuator 40, moving the same in clockwise direction to engage lug 39 and release pawl 36 from engagement with disc 35. Accordingly, wheel 35 being free to rotate, it is moved in a direction to straighten the toggle 43 thereby raising lever 44, pivoted at 45, and supporting at its free end, as by a link 46, 150

. connections with conductors 53 partment the entire the'protective diaphragm, and the circuit breaker a pair of insulating supports 47. and 48 upon which are respectively mounted the movable contacts 26 and 27 of the disconnecting device. Contacts 26 and 2'7 are electrically connected through flexible braided conductors 49 and 50 to stationary insulating supports 51 and 52 providing terminal and 54 leading to apparatus in the superstructure as hereinafter described. I a

A bell crank member 55 having a fixed pivot 55a is connected at one end through a link 56 with themovable shutter 30. The opposite end of the bell crank is disposed in the path of a lug 5'7 carried by'bushings ,47 and 48 and movable therewith. As illustrated in Fig. 3, rotation of wheel 33 in the proper direction serves to straighten toggle 43 thereby rotating lever 44 in counter clockwise direction to separate contacts 26 and 27 from their coacting contacts and to withdraw them upwardly into the disconnecting switch compartment. As the movable contacts near the limits of their upward movement, lug 57, comprising an element of a lost-motion connection between the operating mechanism and the shutter, comes into engagement with the coacting arm of bell crank 55 to rotate it in clockwise direction and thereby move the insulating shutter 30 towards, the left to close apertures 28 and 29. It will be apparent that rotation of wheel 33 in the opposite direction, when not restrained by the aforesaid interlocking means, permits the shutter 30 to move to the right, as under bias of a spring (not shown) to open apertures 28 and 29 and to project the movable contacts downwardly into engagement with the contacts 24 and 25.

In order that the operator may readily determine the position of the disconnecting device, a visual indicator 58 is operatively connected in any suitable manner, as by linkages 59 with lever 44 whereby the position of indicator 58 is indicative of the position of the movable contacts.

When the main circuit breaker has been tripped open and the disconnecting and isolating operations above described the circuit breaker may be removed from its compartment. To this end, the door or panel 8 is opened and a conventional truck 59, which may be of the type usually employed in factories for moving about heavy objects is moved into the cubicle and underneath the tray 13 upon which circuit breaker is mounted. After the truck has been elevated in a well known manner to raise the tray 13 slightly from the floor of the comunit comprising the tray,

and its operating mechanism are moved out of the cubicle without disturbing any of the accessory equipment. The operator is therefore able to effect the disconnecting operation at will independently of the movement of thecircuit breaker. In other words, the disconnecting operation and withdrawal of the circuit breaker from the cubicle are not necessarily concurrent as in the case where the movable contacts of the disconnecting device are mounted on the circuit breaker itself.

The disconnecting switch compartment, whose lower portion comprises barrier 11, a vertically extending portion 60, and a removable insulating barrier 61, houses the usual potential transformer 62 whose secondary leads may be disposed. as at 63:

The upper part of the cubicle or superstructure comprises two compartments, the compartment defined by the top section 6 and partition 9 being have been completed,

designated as the transfer bus compartment, and the compartment defined by .partitions 9 and 10 being designated as the main bus compartment. The main bus compartment is divided into two sections" by a removable insulating barrier 70, one

of which contains supporting members for the current transformer 64 to which are mounted conductors 65 connecting the current transformer through partition 9 to a transfer switch 66. The primary lead cable 64a of the current.

transformer 64, extends through partition 10 along the rear wall of the cubicle within the passage 5a. As illustrated, the primary cable passes out through the bottom of the cubicle, but it is apparent that it may extend, if desired, along the rear wall thereof through the top. The main busses are designated at 69 in the front section of the main bus compartment, the circuit breaker in the present instance being of the three phase type, as illustrated in Fig. 2 wherein three individual sets of contacts, such as 26 and 27 are simultaneously operated by the operating wheel 33 I The transfer 66 within the transfer bus compartment is isolated from the remainder of the compartment by a switch supporting partition or wall 66a. Switch 66 may be operated either singly or in gang connection in any suitable manner as by a pivoted rod 67 operated through a gearing 68 and crank 68a suitably disposed along the front of the cubicle.

The transfer busses 71 are mounted upon insulating supports in the usual manner in the rear of the transfer bus compartment and are individually connected to corresponding" contacts of the transfer switch.

It shall be understood that the current and potential transformers together with their disconnecting devices may be mounted upon themmovable circuit breaker unit as in the case of certain types of truck-type panels previously referred to. Furthermore, it is not essential that the movable contacts or the disconnecting device be vertically movable or that they shall partake only of rectilinear movement. If desired, the movable disconnecting contacts may be laterally disposed with respect to the circuit breaker so that they partake of horizontal movement; or they may be pivotally mounted, as in the case of usual gang operated switches with the pivotal mountings disposed either on the circuit breaker unit or on the frame of the cubicle. In any event the disconnecting and isolating operation will take place independently of movement of the circuit breaker. 1

With reference to Fig. 2 it will be noted that the cubicle takes up very little space and presents a comparatively compact appearance. This is made possible without sacrificing any of the usual safety features by eliminating'the comparatively massive and eleborate mechanism for effecting the disconnecting operation either by horizontal or vertical movement of the breaker. Furthermore, due to the fact that no rear doors are necessary, the cubicle may be disposed against a wall thereby increasing the effective floor space of the station in which the cubicle is located. a

The protective diaphragm 21, together with the front section or door 8 of the cubicle, form a double barrier tending to practically el minate oil throwfrom the cubicle in the event that the oil circuit breaker under certain operating conditions violently ejects quantities of oil therefrom. In prior constructions, wherein the front door or wall of the cell is relied upon to protect the operator exteriorly of cubicle, hot oil has been known to be projected through the spaces and cracks around the door or wall to a considerable distance, injuring workmen about the station. By providing a double barrier to form a dead space oil thrown from the circuit breaker is precluded from injuring an operator even though he may be standing close to the cubicle at the time of expulsion of oil from the breaker.

It shall be understood that changes in construction and arrangement of the apparatus within the cubicle may be made without departing from the spirit of my invention. For example, the superstructure of the cubicle may be of the metal-clad type wherein the bus bars and accessory equipment are immersed or embedded in suitable insulating material. Although the present arrangement whereby a single truck of inexpensive construction may serve a plurality of cubicles to withdraw -the circuit breaker therefrom when desired is preferable, due to the saving in material and cost of construction, it is apparent that the circuit breaker may be mounted upon its own truck in the usual manner, if so desired.

The circuit connections for the'circuit breaker with respect to its disconnecting switches and main and transfer busses may be made in any suitable manner which will afford suificient electrical protection and flexibility of operation, and by way of example, the single line diagram illustrated in Fig. 4 shows one way in which the system may be connected. The oil circuit breaker '70, '71 and 72 are indicated as being within separate cubicles as defined by the dotted lines, the incoming line '73 being connected with breakers and 71, for optional connection to the main bus '74 or the transfer bus 75. The disconnecting switches for breakers '70 and '71 are diagrammatically indicated at 76 and '77 respectively. The circuit breaker 72 is interposed together with its disconnecting means 78, between the main bus and outgoing feeder 79. Feeder 79 may likewise be connected to the transfer bus through switch 80.

For the purpose of enabling the oil circuit breaker to be tested and electrically operated in a well known manner, a suitable secondary disconnecting device or switch, not shown, may be employed.

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

l. The combination with a cubicle compris-' compartment of a removable circuit within said compartment, a protective wall section mounted on and carried by said unit forming, when the breaker unit is in operative position, the front wall of said compartment, and a movable instrument panel comprising a front wall of the cubicle and spaced from said wall section whereby inspection of the rear of the instrument panel may be had without disturbing the breaker unit.

2. The combination with a cubicle comprising a circuit breaker compartment and a second compartment adjacent thereto, of a removable circuit breaker unit disposed within said firstnamed compartment, disconnecting switching structure comprising a set of movable contactmembers mounted within the second compartment, flexible conductors connecting said movable contact members to fixed terminals in said second compartment, the cooperating set of contact members being mounted on the circuit ing a breaker unit mounted breaker, an insulating shutter arranged to be interposed between said sets of contact members, and operating mechanism mounted within said second compartment for withdrawing the movable contacts of the disconnecting switch entirely into the second compartment and interposing said insulating shutter between the stationary and movable contacts whereby complete electrical isolation of the circuit breaker is effected. i

3. Electrical switchgear comprising in combination a cubicle comprising a plurality of compartments, a removable circuit breaker unit disposed in one of said compartments, disconnecting switching structure for isolating the circuit breaker disposed in another of said compartments, a protective diaphragm mounted on and carried by said removable unit forming a front wall of the circuit breaker compartment, said diaphragm being spaced from the front wall of the cubicle to form an operating compartment, an operating member for the disconnecting switching structure and operating means for the circuit breaker both disposed in said last-named compartment, and a hinged front panel comprising a front wall of the cubicle for permitting access to the aforesaid operating compartment.

4. Electrical switchgear comprising a housing having a plurality of compartments, a removable circuit breaker unit disposed in one of said compartments, bus bars and accessory equipment disposed in another of said compartments, a disconnecting device for electrically isolating the circuit breaker with respect to its bus bars and accessory equipment comprising stationary and movable contacts, the stationary contacts of said device being mounted on and carried by the circuit breaker, a partition through which said movable contacts are withdrawn to the isolating position, a movable insulating shutter mounted on said partition adapted to be interposed between the movable and stationary contacts, and mechanism operativeiy connected to said movable contacts and having a lost-motion connection with said shutter for effecting by a single operation separation of said contacts and movement of the insulating shutter therebetween.

5. Electrical switchgear comprising in combination a cubicle, a circuit breaker unit mounted within the cubicle and spaced and separated by a diaphragm from the front wall of the cubicle, operating means for the circuit breaker,- a disconnecting device for electrically isolating the circuit breaker from other parts of the system in which it is connected, and an operating member for said disconnecting device, the operating member and operating means for the circuit breaker both being disposed in the space between the diaphragm and iront wall of the cubicle.

6. Electrical switchgear comprising in combination a cubicle, a hinged section forming a front wall 0! the cubicle comprising an instrument panel, a removable circuit breaker unit disposed within the cubicle spaced and separated from said instrument panel whereby inspection of the rear of the panel may be had without change in position 01 the circuit breaker unit, and supporting structure for the circuit breaker unit for permitting its withdrawal from the cubicle through the opening normally closed by the instrument panel.

.7. Electrical switchgear comprising a cubicle having a plurality of compartments containing electrical equipment, a circuit breaker disposed in one of said compartments, structure for supporting said circuit breaker in spaced relation with respect to the floor of its compartment whereby withdrawal of the circuit breaker from the cubicle may be effected by auxiliary truck apparatus rolled beneath said breaker, disconnecting switching structure for electrically disconnecting and isolating the circuit breaker from other equipment inv the cubicle, and operating mechanism carried by said cubicle for simultaneously opening the contacts of the'disconnecting structure prior to withdrawal 0! the circuit breaker from its compartment.

8. Electrical switchgear comprising in combination a cubicle comprising a plurality of compartments separated by partitions of insulating material, a removable circuit breaker unit mounted on a tray on the floor of the cubicle within one of said compartments, a protective diaphragm mounted on and carried by said unit spaced from the front wall of the cubicle to form an operating compartment, disconnecting switching structure for isolating the circuit breaker disposed in a compartment adjacent to and above the circuit breaker compartment, an operating wheel for the disconnecting switch disposed together with operating means for the circuit breaker in said operating compartment, and interlocking means coacting with said operating wheel and operating means whereby said wheel may be rotated to effect withdrawal of the movable contacts of the disconnecting switch from the stationary contacts in the circuit breaker compartment only after the tripping operation of the breaker.

9. Electrical switchgear comprising a cubicle having a circuit breaker compartment, a removable circuit breaker disposed within said compartment, a removable tray for supporting the breaker in spaced relation to the floor of the compartment, and disconnecting switching structure for electrically disconnecting andisolatin'g the circuit breaker from the system in which it is connected while the circuit breaker is stationary within its compartment, said breaker adapted to be removed laterally from the cubicle upon said tray after said disconnecting and isolating operation.

JAMES H. POWERS.

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