US2727105A

US2727105A - Sectionalizing switch gear

Info

Publication number: US2727105A
Application number: US250990A
Authority: US
Inventors: John L Turner
Original assignee: AB Chance Co
Current assignee: AB Chance Co
Priority date: 1951-10-12
Filing date: 1951-10-12
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

Dec. 13, 1955 TURNER 2,727,105

SECTIONALIZING SWITCH GEAR Filed Oct. 12, 1951 2 Sheets-Sheet l FIG.I.

Dec. 13, 1955 J. L. TURNER SECTIONALIZING SWITCH GEAR 2 Sheets-Sheet Filed Oct. 12, 1951 United States Patent SECTIONALIZENG swrrcrr GEAR John L. Turner, t. Louis, Mo, assign-or, by mesue assignments, to A. B. Chance Company, entraha, Mo, a corporation of lVIiss curi Application October 12, E 51, Serial No. 250,999

4 Claims. (Cl. 230-425) This invention relates to sectionalizing switch gear, and more particularly, to outdoor disconnect switch gear for use at the junction of at least three overhead conductors in a power transmission system. It is an improvement upon structures such as shown in the U. S. Patent 2,470,576 of Pollock et al. entitled Gang Operated Switch, dated May 17, 1949, and in my copending U. S. patent application Serial No. 247,320, filed September 19, 1951, for Quick-Break Switch.

Among the several objects of this invention is the provision of simple and compact switch gear of the type described adapted to sectionalize a high-voltage transmission line and at the same time provide for disconnecting a feeder from the line without interrupting the line; the provision of switch gear of this type adapted to form a sectionalizing junction for two feeders with a supply line; the provision of such switch gear providing improved safety; and the provision of such switch gear permitting economy in power transmission systems by elimination of equipment heretofore required at substations.

To accomplish these objectives 1 have provided switch gear comprising a frame adapted to be mounted upon a pole generally at the level of the overhead conductors. The frame has a crossarm and a cantilever extending transversely from the crossarm. First and second line terminals are located at the ends of the crossarm and a third line terminal is located at the outer end of the cantilever. Each line terminal is in the form of a connector on a fixed insulator carrying a switch contact and to which is connected a conductor. First and second rotary insulators are located intermediate the ends of the cantilever adjacent the first and second line terminals, respectively, and a third rotary insulator is supported intermediate the ends of the cantilever adjacent the third line terminal. A switch blade is fixed to each of the rotary insulators for cooperation with the contact on the adjacent fixed insulators; and a bus bar, which is supported upon the rotary insulators, permanently connects all of the switch blades in common. More specifically, the switch lades are connected to the bus bar by a wiping brush arrangement. Other features will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of which will be indicated in the following claims.

In the accompanying drawings, in which one of various possible embodiments of the invention is illustrated,

Fig. l is a circuit diagram of a power transmission system incorporating the switch gear of this invention;

Fig. 2 is a perspective view of the switch gear;

Fig. 3 is a top plan view of the device shown in Fig. 2; and,

Figs. 4 and 5 are detailed top and side views showing the connection between a switch blade and the bus bar.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

ICQ

It will be understood that, in power transmission systems, oil circuit breakers or switches are located at the generating stations and the substations to open the circuits under load, and that disconnect switches are employed in conjunction with the oil circuit breakers to isolate various portions of the system for purposes of inspection and repair. In high voltage systems, outdoor type disconnect switches are used because they economically permit the wide separation of conductive parts necessitated by such high voltages.

In setting out the features of this invention, reference is made to Fig. l, which illustrates one phase of a typical power system incorporating the switch gear of this invention employed in several different ways, by way of example. There is a loop circuit L supplied from supply feeders F1 and F2. The latter connect with suitable sources of supply (not shown). The supply feeder F1 is connected to a straight section of the loop L by a switching device S1 of this invention having a line terminal I. connected to the supply line and

other line terminals

3 and 5 connected to sectionalize the loop. The other supply feeder F2 is connected at a corner of the loop circuit to a terminal 5 of switch gear S2. The

other line terminals

1 and 3 of the switch gear S2 are connected to sectionalize the loop L. The loop circuit in turn supplies lateral feeders F3, F4 and F5. These feeders are connected to the line terminals 1 of switching devices S3, S4 and S5, respectively, and the

line terminals

3 and 5 of the switching devices S3, S4 and S5 are connected to sectionalize the loop.

The feeders F3, F4 and F5 lead to substations, one of which is shown at SS. Such a substation generally includes a transformer T for reducing the voltage, an oil switch or oil circuit breaker OS for opening the circuit under load and a bus B to which are connected distribution feeders D1 The latter distribute 12' wet to consumers.

As will be shown, the switch gear of this invention as exemplified at S1, S2, S3, S4 and S5- permits any part of the system to be taken out of service or sectionalized without interfering with the operation of the remainder of the syst m. An additional advantage or" my switch gear is in the economy of equipment. Heretofore, it has been necessary to locate a disconnect switch at the substation SS to permit inspection and repair of the substation. Increased safety is also afforded in that all conductors at a junction point may be disconnected independently of one another.

The switch gear of the invention shown diagrammatically in Fig. l is fully illustrated in Figs. 2-5. it will be understood, however, that the disclosure is for one line or phase and that, in a three-phase system, there may be three devices mounted in vertically spaced relation upon a common pole and concurrently operated by common control rods.

Referring to Figs. 2 and 3, each switching device comprises a frame 9 secured to a pole 7. The frame 9 has a horizontal crossarm 1i and a cantilever l3 projecting transversely of the crossann from the pole. The cantilever is formed by a pair of spaced horizontal arms 15 which converge to a common end 17. At la is a verti cal channel-type member to which is secured the crossarm 13 and by means of which the entire frame 9 is secured to the pole. inclined struts 21 brace the crossarm 11 on the channel member and struts Z3 brace the cantilever 13 with the channel member. A T-shaped brace 25 is formed at the outer end of the cantilever.

The frame forms a support for three horizontal break switches adapted to connect together three overhead conductors 2'7, 29 and 31 leading to and supported by the frame.

Conductors

29 and 31 are generally aligned with the crossarm 11 of the frame, whereas the conductor 27 is generally transverse or lateral to the other conductors and is supported from the end 17 of the cantilever. The three

conductors

27, 29 and 31 are connected to the

line terminals

1, 3 and 5, respectively, which cooperate respectively with

movable terminals

33, 35 and 37 to form the aforementioned horizontal break switches. The fixed terminals and 3 are located at the ends of the crossarrn 11, and the fixed terminal 1 is located at the end 17 of the cantilever. The

movable terminals

33, and 37 are located on the cantilever intermediate its ends with the movable terminal 33 being relatively adjacent the fixed terminal 1, the movable terminal 35 being relatively adjacent the fixed terminal 3 and the movable terminal 37 being relatively adjacent the fixed terminal 5.

Each of the fixed terminals comprises a pin-type insulator 39 projecting vertically upward and carrying at its upper end a switch contact clip 41 of the enclosed floating contact type. Each of the conductors is mechanically supported from the frame by means of an outrigger string of suspension insulators 43 tied to an extremity of the frame, and each conductor is electrically connected to the contact 41 at the adjacent terminal by means of a jumper 45 secured by a clamp 47 extending from the contact. It will therefore be seen that both the conductors and the contacts are supported by the frame in insulated relation therefrom.

Each of the movable terminals comprises a pin-type insulator 49 projecting vertically upright from a thrust bearing 51 secured in the cantilever portion 13 of the frame. 1 he thrust bearings 51 for the

movable terminals

35 and 37 are fastened in the arms 15 of the frame, and the thrust bearing for the movable terminal 33 is fastened in the T-shape brace 25.

The movable terminals are controlled by means of operating rods 53 which extend from the frame member downward along the pole 7 for operation from ground level. As shown, there is an operating rod for each movable terminal, the rods being disposed around the pole in the same relative location as the

fixed terminals

1, 3 and 5. Handles 55 may be attached to the bottom of the operating rods 53, or the rods may be under the control of some type of automatic motor means. Each rod extends through a thrust bearing 57 carried on a bracket 59 fastened to the crossarm 11.

Sleeves 61 are fastened to the tops of the operating rods 53, for example by set screws. Cranks 63 are fastened to the sleeves 61 to drive connecting links 65 reaching toward the three movable terminals. The links 65 are connected at their other ends to second cranks 67 which are fastened to the rotary insulators 49. Each rotary insulator 4'9 is thereby rotated by an operating rod 53 from ground level.

To the top of each of the rotary insulators 49 there is fastened at 6-3 a bracket 69 which clamps one end of a switch blade 71. for each terminal. Each switch blade 71 is flattened at its other end to enter a mouth 73 in the contact clip 4i mounted upon the adjacent fixed insulator 39. As shown, the months 73 of the contact clips on the three fixed terminals are arranged so that the switch blades may swing outwardly therefrom. For example, the switch blade for the movable terminal 35 swings'outwardly from the end of the crossarm to the position indicated by dotted lines. Similarly, the switch blade for the movable terminal 37 swings outwardly away from the other end of the crossarm. The switch blade for the movable terminal 33 swings counterclockwise as viewed in Fig. 3 toward the movable switch terminal 35. In order to prevent interference between the switch blades for the

movable terminals

33 and 35, the switch blade for the movable terminal 33 and the associated switch parts are in a plane slightly elevated with respect to the switch parts for the terminals 35 and 37 (Fig. 2).

Arcing horns are provided to interrupt arcs formed in opening the switches. it will be understood that although a circuit breaker is employed to openthe circuit under load, there may be charging current resulting from the line capacitance and transformer exciting current to be interrupted by the disconnect switches. The arcing horns are described in detail in the aforementioned patent application, but briefly include a cantilevered spring whip 75 formed of a resilient electrically conductive rod having one end coiled into a helical coil spring with the axis of the spring transverse to the length of the whip. The spring is contained in a spring housing 77 attached to the switch blade 71 and is in electrically conductive relation with the switch blade.

Mounted on each contact 41 is a fixed arcing horn 79 formed as a detent for the spring whip 75 of the respective switch blade. This fixed arcing horn 79 is adapted to provide a delayed quick opening action with the spring whip 75 after withdrawal of the switch blade 71 from its contact clip 41. As explained in the aforementioned patent application, the end of the whip 75 is caught in a notch 81, so formed and positioned with respect to the whip that the free end of the whip becomes wedged in the notch and is withdrawn in an axial direction upon opening of the switch blade. In closing the switch blade, the whip rides up a cam 83 formed on the fixed arcing horn and drops into the aforementioned notch.

The three switch blades are permanently connected together by means of a bus bar 85 supported on the rotary insulators of the three movable terminals. As shown in Fig. 4, each of the rotary insulators 49 has a stud 87 projecting upwardly through the attached bracket 69. A contact plate 89 is supported on the stud 87 by lock nuts 91in such manner as to permit rotation, and the three contact plates are jointed together by conductive straps 91. The brackets 69 in turn carry brushes 93 secured at 68 and having inserts 95 of silver or the like which engage annular inserts 97 of silver or the like secured to the bottom surface of the contact plates 89. The contact plates thereby serve as sleet hoods for the wiping surfaces, and the elimination of pigtails provides for long life and safety against accidental grounding with the frame.

Referring back to Fig. 1, the switch gear is particularly adapted to provide improved sectionalizing action. As an example, the supply feeder F1 is shown disconnected at terminal 1 of the switch gear S1 to permit repair of the feeder while at the same time the loop L is maintained closed through

line terminals

3 and 5 of the device S1. As another example, a portion of the line betweenthe devices S2 and S5 is disconnected at their

terminals

1 and 5, respectively, without interfering with the supply from feeder F2 or the supply to feeder F5. Additionally, it will be noted that the substation SS may be taken off the line by opening the device S3 at terminal 1. Therefore, there is no need to have a disconnect switch at the substation as required heretofore. Moreover, the substation is not only disconnected at S3 but the feeder F3'1eading' into the substation is disconnected so that a Worker is afforded complete safety.

The structure for carrying out the invention is simple and compact, the stationary insulators at 1, 3 and 5 being arranged on the corners of a triangle within the confines of which the group of rotary insulators is mounted.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, 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.

I claim:

1. Sectionalizing switch gear for use at a group of three overhead line terminals two of which are in a first loop circuit and one of which is in a second feeder of tap circuit; comprising a single structure adapted for overhead single polem'ounting at said group, three stationary insulators oii the'stiucture', contacts o'n-saidinsulators,said

contacts respectively being connected with said line terminals, three rotary insulators carried upon said structure, conductive switch blades carried respectively by said rotary insulators, stationary interconnected conductive means between said rotary insulators, said stationary conducting means being constituted by a rigid bus bar construction having relatively rotary connections with said rotary insulators respectively and being supported and held thereby independently of any fastenings to said structure, movable connections between all of said switch blades and said stationary conductive means, said movable connections being constituted by brush means, one each of said switch blades being rotary into and out of engagement with the contacts respectively connected with said line terminals for the first circuit and the other switch blade being rotary into and out of engagement with the contact connected with the line terminal of the second circuit, and individual operating means for individually rotating each of said rotary insulators from a single operating station adjacent the pole at ground level for individual connection or disconnection of said line terminals.

2. Apparatus made according to claim 1, wherein all of said insulators are upstanding from a horizontal common platform formed by said structure and wherein two of said switch arms are operative to swing in a common substantially horizontal first plane and the third switch arm swings in a second plane elevated relative to the first plane.

3. Sectionalizing switch gear for use at a group of three overhead line terminals two of which are in a first loop circuit and one of which is in a second feeder or tap circuit; comprising a single structure adapted for overhead single-pole mounting at said group, three stationary insulators on the structure, contacts on said insulators, said contacts respectively being connected with said line terminals, three rotary insulators carried upon said structure, said stationary insulators being located at the corners of a triangle and the rotary insulators being located within the boundaries of said triangle, conductive switch blades carried respectively by said rotary insulators, stationary interconnected conductive means between said rotary insulators, movable connections between all of said switch blades and said stationary conductive means, one each of said switch blades being rotary into and out of engagement with the contacts respectively connected with said line terminals for the first circuit and the other switch blade being rotary into and out of engagement with the contact connected with the line terminal of the second circuit, and individual operating means for individually rotating each of said rotary insulators from a single operating station adjacent the pole at ground level for individual connection or disconnection of said line terminals.

4. Sectionalizing switch gear for use at a group of three overhead line terminals two of which are in a first loop circuit and one of which is in a second feeder or tap circuit; comprising a single structure adapted for overhead single-pole mounting at said group, three stationary insulators on the structure, contacts on said in sulators, said contacts respectively being connected with said line terminals, three rotary insulators carried upon said structure, all of said insulators being upstanding from a horizontal common platform formed by said structure, said stationary insulators being located at the corners of a triangle and the rotary insulators being located within the boundaries of said triangle, conductive switch blades carried respectively by said rotary insulators, stationary interconnected conductive means between said rotary insulators, movable connections between all of said switch blades and said stationary conductive means, one each of said switch blades being rotary into and out of engagement with the contacts respectively connected with said line terminals for the first circuit and the other switch blade being rotary into and out of engagement with the contact connected with the line terminal of the second circuit, two of said switch arms being operative to swing in a common substantially horizontal first plane, and the third arm being operative to swing in a second plane elevated relative to the first plane, and individual operating means for individually rotating each of said rotary insulators from a single operating station adjacent the pole at ground level for individual connection or disconnection of said line terminals.

References Cited in the file of this patent UNITED STATES PATENTS