US2050323A - Switch gear - Google Patents

Description

'Aug. 11, M HOBBS ET AL SWITCH GEAR Filed April 2, 1955 3 Sheets-Sheet 1 &

INVENTORS Mal/77019 H Hobs aim Harald/7.

. Ail 11, 1936. M, H HOBBS ET AL 2,050,323

' SWITCH GEAR I Filed April 2, 1955 3 Sheets-Sheet 2 WITNESSES: INVENTORS May/7'06 H Hobfis and Hdi'O? H P1199.

Aug. 11, 1936. M. H. HbBBs ET AL. 05 3 SWITCH GEAR Filed April 2, 1935 KSheetS-Sheet 5 W ;ATTO% EY L Patented Aug. 11, 1936 UNITED STATES PATENT OFFICE SWITCH GEAR Vania Application April 2, 1935, Serial No. 14,262

8 Claims.

Our invention relates, generally, to switchgear and, more particularly, to electrical switchgear of the oil-filled metal-enclosed type wherein an automatic circuit breaker may be readily dis- 5 connected from its associated circuits.

In general, previously known types of oil-filled metal-enclosed switchgear are not applicable to high voltage circuit breakers of the floor mounted type when it is desirable to utilize an overhead 10 bus bar structure.

An object of our invention, generally stated, is to provide electrical switchgear which shall be simple and compact in structure and which may be economically manufactured and installed.

.:5 A more specific object of our invention is to provide for disconnecting floor mounted circuit breakers from an overhead bus structure by bodily movement of the circuit breakers.

Another object of our invention is the provi- 20 sion of a common actuating means for simultaneously moving a plurality of circuit breaker units to disconnect them from associated circuits.

Still another object of our invention is to provide for interlocking the actuating mechanism for 25 disconnecting a circuit breaker unit from its associated circuits with the circuit breaker operating mechanism.

Other objects of our invention will be explained fully hereinafter or will be apparent to those 30 skilled in the art.

In accordance with one embodiment of our invention each pole of a three-phase circuit breaker is mounted in a rotatable tank unit. The tank units are rotated simultaneously about their ver- 35 tical axes by a racking device through an angle of approximately 60 degrees, which disconnects the breaker terminals from the bus structure and connects them to grounded terminals. The rotating mechanism is interlocked with the circuit 40 breaker operating mechanism to prevent the disconnecting contacts from being opened when the main circuit breaker contacts are closed. The disconnecting contacts for each breaker are mounted in a compartment above the breaker which permits the use of an overhead bus structure.

For a fuller understanding of the nature and objects of our invention reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure l is a view, partially in section and partially in elevation, of a switchgear structure 55 embodying our invention;

Fig. 2 is a view, partially in plan and partially in section, of the structure shown in Fig. 1;

Fig. 3 is a View, in vertical section, taken along the line IIIIII of Fig. 1;

Fig. 4 is a view, in section, taken along the 5 line IV-IV of Fig. 3, showing the disconnect contact members for one circuit breaker unit, and

Fig. 5 is an enlarged view of a portion of the apparatus, showing the interlocking device between the circuit breaker operating mechanism and the rotating mechanism.

Referring now to the drawings, and particularly to Fig. l, the metal-enclosed switchgear illustrated comprises three circuit breaker units It), there being one unit for each phase of a three-phase power system. Since the three units are of similar construction, the structure of only one unit will be described in detail in the present specification. The breaker units are disposed within a structural steel framework comprising upright members H and longitudinal members 12. The framework supports a mechanism I3 (see Fig. 5), enclosed within a housing l4, for closing the contact members of all three breakers simultaneously, in a manner well known in the art. The pull rods for connecting the closing mechanism l3 to the operating mechanism of each breaker unit are enclosed within pipes l5, supported by the structural framework.

Referring to Fig. 3, each one of the breaker units I0 comprises an enclosing casing l6 which is mounted on wheels or rollers l1 and a centrally disposed pin I8, which rests in a bearing block [9 underneath the center of the housing l6, thereby making the housing rotatable about 5 its vertical axis. The circuit breaker maybe of the oil type having relatively movable contact members immersed in oil contained within the housing 16. Fixed contact members 2| and 22 are bridged by a movable contact member 23,

which is carried by a lift rod 24, when the breaker is actuated to the closed position by the operating mechanism 13. The open position of the breaker contact members is indicated by the broken lines in Fig. 3. 5

The contact members 2| and 22 are mounted on the lower ends of terminal members 25 and 26, respectively. The terminals 25 and 26 are mounted in a partition 27, which divides the housing l6 into a lower or breaker compartment 28 and an upper or disconnect compartment 29. A disconnecting switch contact member 3| is mounted on the upper end of the terminal 25 and a similar disconnecting switch contact member 32 is mounted on the upper end of the terminal 26.

Stationary disconnecting switch contact members 33 and 34, which coact with the contact members 3| and 32, respectively, are mounted on the lower ends of terminal members 35 and 36, respectively.

The terminal members 35 and 33 are mounted in a stationary cover 3? for the housing i 6. The cover 31 is supported by the longitudinal members I2 of the structural framework. Electrical conductors, such as a bus bar 38 and a feeder cable 39 are disposed above the cover 3 and are connected to the upper ends of the terminal members 36 and 35, respectively. The connection to the bus bar 38 may be protected by a metal enclosure l and the electrical conductors may be protected by insulating sheaths, as shown. A bushing type current transformer 32 and a bushing type potential device 33 may be utilized on the terminal members 36 and 35, respectively, thereby making it unnecessary to provide separate compartments for current and potential transformers.

In this manner a compact and economical switchgear unit is provided, the disconnect compartment being directly above the breaker compartment and the bus bar structure being above the disconnect compartment, thereby permitting an overhead bus structure to be utilized. The three individual units required for a three phase circuit breaker may be mounted in side-by-side relation and they occupy a minimum amount of space.

In order that the disconnecting switch contact members may be separated to disconnect the circuit breaker members from the power conductors, the housing [6 may be rotated through an angle of approximately 60 degrees, as will be more fully described hereinafter. Since the terminal members 25 and 25 are fixed to the housing It, they move with the housing and the-disconnect contact members 3! and 32, which are carried by the terminals 25 and 26, respectively, are moved to the positions indicated by the broken lines in Fig. 4.

As shown in Fig. 4, ground contact members and 46 may be provided to engage the contact members 3| and 32 when the housing it is rotated through the maximum distance, thereby insuring that it will be safe to Work on the circuit breaker mechanism. A window ll may be pro-- vided in each of the housings Hi to permit the operator to see when the movable disconnect members are engaged by the ground contacts.

Access may be gained to the breaker compartment 28 by removing a manhole cover 68 from the side of the housing W. A similar manhole cover 49 is provided in the stationary cover 31 to permit inspection of the disconnect compartment '29.

In order that all three breaker housings may be rotated in unison to separate the disconnecting switches for each unit, the three housings It are connected together by a jointed bar which is connected to a bracket 52 on the side of each housing by a pin 53. In the illustrated embodiment of the invention, the breaker housings are rotated by a racking device comprising a rack 5 and a pinion 55 rotated by a hand'crank 53, although any other suitable means for rotating the breaker housings may be utilized. One end of the rack 54 is connected to the bracket 52 on one of the housings it by a pin 57 disposed in a slot 58 in the bracket 52. Thus, the three housings may be rotated about their vertical axes by turning'the crank56 to drive the rack 54, which will cause the housings Hi to rotate on their supporting wheels Ill. The racking device is partially enclosed by a metal housing 59 located at one end of the housing M, which encloses the operating mechanism 93 for the circuit breakers.

With a view to preventing the separation of the disconnecting contact members while they are carrying current, the rotating device is so interlocked with the breaker operating mechanism l3 that the mechanism is tripped to open the circuit breaker contact members before the disconnect contact members are separated, thereby preventing the drawing of an are between the disconnect contact members.

The interlocking device shown comprises a roller 6! mounted on the lower end of a vertical lever 62 which is pivotally supported on one end of the housing 53 by a bracket 63. The upper end of the lever 62 is connected to the tripping trigger M of the operating mechanism l3 by a horizontal rod 65. Two notches 6t and Gil are provided in the side of the rack bar 5 3 for the roller 6i which is held in the notches by a spring 68 connected to the lever 62.

As shown, the notch 66 is so located in the rack 55 that the roller 6! is in the notch when the disconnecting contact members 3i and 32 are engaged by the members 33 and 34, respectively, thereby permitting the operating mechanism It to function in the normal manner to open and close the circuit breakers. However, in the event that the rack 5c is driven by the pinion 55 in the direction to rotate the housings it to separate the disconnect contact members, the roller 68 is raised out of the notch 66 and the lever $2 is actuated to release the trigger 64 which trips the circuit breakers in the housings it before the disconnecting switches are opened.

The notch 6? may be so located in the rack 55 that the roller 68 will drop into it when the housings it are rotated to the position in which the disconnect contact members 35 and 32 are engaged by the ground contacts and t6, respectively, which will permit the breaker mechanism to be operated for testing purposes while in the grounded position. However, the trigger 65 will be immediately released to trip the circuit breakers should an attempt be made to rotate the housings back to their original positions, as shown in the drawings, with the circuit breaker contacts closed.

In this manner, it is impossible to either open or close the disconnected switches under load, thereby preventing injury to these switches. Furthermore, it is impossible to close the circuit breakers while they are being rotated from the operating position to the grounded position, or vice versa, since the operating mechanism i3 is of the trip free type and will not operate to close the circuit breakers when the trigger 64 is released by the interlocking device, as described hereinbefore.

Since the operating mechanism i3 is of a type well known in the art, it is believed to be unnecessary to describe it in detail in the present i application. Briefly it comprises a pivotally mounted operating lever H, to which the pull rod for operating the breakers is connected, a closing solenoid l2 and a trip coil E3. The lever H is operated by the solenoid 12 through a full automatic or trip free mechanism which includes a lever l6 and the trigger St. The trigger 6 t may be released by energizing the trip coil 73 or by means of the rod 65 which is actuated by the interlocking device described hereinbefore.

From the foregoing description, it is evident that we have provided a switchgear structure which is simpler and more compact than previously known structures of the same type. Furthermore, the individual switchgear units herein described may be readily grouped together and operated in unison to constitute a structure suitable for use in a three phase power distribution system having the power conductors disposed above the switchgear structure, thereby conserving on space and increasing the safety of the structure.

Since numerous changes may be made in the above-described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. Electrical switchgear comprising a circuit breaker having an enclosing housing, means for rotatably supporting the housing, electrical conductors disposed above the housing, a stationary cover for the housing, terminal members disposed in the housing, terminal members mounted in the cover above the terminal members in the housing and connected to the electrical conductors, coacting disconnecting contact members carried by said terminal members, and means for rotating the housing independently of the cover to separate the disconnecting contact members.

2. Electrical switchgear comprising a circuit breaker having an enclosing housing, means for rotatably supporting the housing, a stationary cover for the housing, means for supporting the cover independently of the housing, electrical conductors disposed above the cover, terminal members disposed in the housing and movable therewith, terminal members mounted in the cover above the terminal members in the housing and connected to the electrical conductors, coacting disconnecting contact members carried by said terminal members, and means for rotating the housing independently of the cover to separate the disconnecting contact members.

3. Electrical switchgear comprising a circuit breaker having an enclosing housing, means for rotatably supporting the housing, a stationary cover for the housing, a structural framework for supporting the cover independently of the housing, electrical conductors disposed above the cover, terminal members disposed in the housing and movable therewith, circuit breaker contact members mounted on one end of said terminal members, disconnecting contact members mounted on the other end of the terminal members, terminal members mounted in the cover and disposed in substantially vertical alinement with the terminals in the housing, one end of the terminals in the cover being connected to the electrical conductors, disconnecting contact members carried by the other end of said terminals and coacting with the disconnecting contact members on the terminals in the housing, and means for rotating the housing about its vertical axis independently of the cover to separate the disconnecting contact members.

4. Electrical switchgear comprising a plurality of circuit breakers having enclosing housings, means for rotatably supporting the housings, a stationary cover for each of the housings, a structural framework for supporting the covers independently of the housings, electrical conductors disposed above the covers, terminal members disposed in the housings and movable therewith, terminal members mounted in the covers above the terminal members in the housings and connected to the electrical conductors, coacting disconnecting contact members carried by said terminal members, and means for rotating the housings in unison independently of the covers to separate the coacting disconnecting contact members in each of the housings.

5. Electrical switchgear comprising a circuit breaker having an enclosing housing, means for rotatably supporting the housing, relatively movable circuit breaker contact members disposed within the housing, terminal members for supporting certain of the circuit breaker contact members, disconnecting contact members disposed above the breaker contact members and supported by said terminal members, a stationary cover for the housing, means for supporting the cover independently of the housing, stationary disconnecting contact members supported by the cover and coacting with the disconnecting contacts supported by the breaker terminals, electrical conductors disposed above the cover and connected to the stationary disconnecting contact members, and means for rotating the housing about its vertical axis independently of the cover to engage and disengage said disconnecting contact members.

6. Electrical switchgear comprising a circuit breaker having an enclosing housing, means for rotatably supporting the housing, relatively movable circuit breaker contact members disposed within the housing, operating means for actuating the circuit breaker contact members into and out of engagement, terminal members for supporting certain of the circuit breaker contact members, disconnecting contact members disposed above the breaker contact members and supported by said terminal members, a stationary cover for the housing, means for supporting the cover independently of the housing, terminal members mounted in the cover, disconnecting contact members carried by the terminal members in the cover and coactihg with the disconnecting contact members on the breaker terminals, electrical conductors disposed above the cover and connected to the terminal members in the cover, means for rotating the housing about its vertical axis independently of the cover to open said disconnecting contact members, and means for interlocking the rotating means with the circuit breaker operating means.

7. Electrical switchgear comprising a plurality of circuit breakers having enclosing housings, means for rotatably supporting the housings, relatively movable circuit breaker contact members disposed within each of the housings, operating means for simultaneously actuating the circuit breaker contact members into and out of engagement, terminal members disposed in each housing for supporting certain of the circuit breaker contact members, disconnecting contact members disposed above the breaker contact members and supported by said terminal members, a stationary cover for each of the housings, means for supporting the covers independently of the housings, terminal members mounted in the covers, disconnecting contact members carried by the terminal members in the cover and coacting with the disconnecting contact members on the breaker terminals, electrical conductors disposed above the covers and connected to the terminal members in the covers, means for rotating the housings in unison about their vertical axes independently of the covers to open said disconnecting contact members, and means for mechanically interlocking the rotating means with the means for operating the circuit breaker contact members.

8. Electrical switchgear comprising a plurality of circuit breakers having enclosing housings, means for rotatably supporting the housings, relatively movable circuit breaker contact members disposed within each of the housings, operating means for simultaneously actuating the circuit breaker contact members into and out of engagement, terminal members disposed in each housing for supporting certain of the circuit breaker contact members, disconnecting contact members disposed above the breaker contact members and supported by said terminal members, a stationary cover for each of the housings, means for supporting the covers independently of the housings, terminal members mounted in the covers, disconnecting contact members carried by the terminal members in the cover and coacting with the disconnecting contact members on the breaker terminals, electrical conductors disposed above the covers and connected to the terminal members in the covers, means for mechanically connecting the housings together, means connected to One of said housings for rotating all of the housings in unison about their vertical axes independently of the covers to open said disconnecting contact members, and means for interlocking the breaker operating mechanism with the rotating mechanism.

MAURICE H. HOBBS.

HAROLD H. RUGG.

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