DE29507391U1 - Multipole switching unit that can be mounted on a mast - Google Patents

Description

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Description

Multipole switching unit mountable on a support mast

The invention relates to a multi-pole switching unit that can be mounted on a support mast, with

- a gas-tight housing filled with an insulating gas,

- at least one interrupter unit operating in the insulating gas for each pole,

- bushings arranged opposite one another on the housing for connecting cable sections to be connected by the switching unit,

- a drive device connected to the switching unit for actuating the interrupter units, - a drive element passing through a wall of the housing in a sealed manner for connecting the drive device (23) with the interrupter units.

A switching unit of this type is described in the Merlin Gerin company brochure: "fluarc PM6 remote controlled Pole Mounted SF6 switch". Such a switching unit can have the particular task of connecting or interrupting two sections of an overhead line. By using an interrupter unit operating in an insulating gas, the switching paths are protected from the influence of the surrounding atmosphere and therefore perfect contact is guaranteed over long periods of time.

It is also known to use a multi-position rotary switch for purposes of the present type, which is used in a similar design in medium-voltage load switchgear that is intended for installation indoors (DE 41 17 057 A).

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The invention is based on the object of creating a weight- and space-saving design of a switching unit of the type mentioned.

According to the invention, this object is achieved by the following features:

- the housing is essentially cylindrical,

- the interrupter units are designed as multi-pole rotary switches with a common actuating shaft, and - the longitudinal axis of the rotary switch is arranged approximately parallel to the longitudinal axis of the housing.

In contrast to the previously usual box-shaped design of the housings of switch units to be mounted on the mast, the cylindrical housing provided can be manufactured with thinner walls at the same internal pressure and is therefore lighter. Furthermore, the cylindrical design of the switch unit makes it easier to attach to a support mast and to connect the feedthrough conductors to the overhead lines because the switch unit can be aligned by turning it relative to its holder, making it easy to reach the desired position.

In the case of switch units with a gas-tight housing, it cannot be ruled out that a pressure increase will occur during operation, which will place undue stress on the housing. In this context, it is recommended that the drive element is located in the bottom wall of the housing and that the opposite roof wall is provided with a protective device against excess pressure. Pressure relief devices of this type are known per se in gas-insulated switch units, e.g. from DE 33 10 782 A.

Within the scope of the invention, a drive chamber for accommodating the drive device can be connected to the housing, wherein the drive chamber is connected by a

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The housing can be formed by a corresponding extension of a casing part extending between the base wall and the roof wall. The switching unit thus has a uniform casing part which encloses both the gas-filled space and the drive chamber belonging to the surrounding atmosphere. This is equally advantageous for the manufacture, strength and corrosion resistance of the switching unit.

The invention is explained in more detail below with reference to the embodiment shown in the figures.

Figure 1 shows a schematic of a support mast for an overhead line with a multi-pole switching unit mounted on the support mast.

Figure 2 shows a partially sectioned view of a switching unit for the application according to Figure 1.

Figure 3 shows a section III-III in Figure 2, while Figure 4 shows the section IV-IV according to Figure 2.

The support mast 1 shown in Figure 1 serves to support two line sections 2 and 3 of a medium-voltage overhead line. The line sections 2 and 3 are insulated and attached to a crossbeam 5 using conventional overhead line insulators 4. A switching unit 6 is attached to the support mast 1 below the crossbeam 5, the housing 7 of which has bushings 8 on opposite sides. The line sections 2 and 3 of the overhead line are connected to the switching unit 6 via connecting conductors 10 in such a way that the line sections 2 and 3 can be connected to one another or separated as required. A control box 11 attached to the support mast 1 below the switching unit 6 allows

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It is possible to actuate the interrupter units 9 contained in the switching unit 6 mechanically or electrically as desired.

The housing 7 of the switching unit 6 is essentially cylindrical in design according to Figures 2 and 4 and has a casing part 12 which is divided by a bottom wall 13 into a switching chamber 14 and a drive chamber 15. The upper end of the housing 7 is formed by a curved roof wall 16, which has a protective device 17 against excess pressure approximately in the middle. In a known manner, the protective device 17 can have a breaking membrane 18 and an outer protective cover 20 which is thrown off when the breaking membrane is activated.

In the switching chamber 14 there is a multi-position rotary switch 21, as can be seen, for example, in the aforementioned DE 41 17 057. The rotary switch 21 contains one interrupter unit 9 for each phase of the network to be switched. Corresponding pairs of connection pieces are designated L1, L2 and L3. Additional connection pieces E are assigned to an earthing section in order to earth the disconnected line section. The longitudinal axes of the rotary switch 21 and the housing 7 run parallel to one another.

In the example shown, the rotary switch 21 is arranged off-center to a certain extent. This is only for the purpose of being able to arrange a deflection device 22 belonging to the rotary switch 21 centrally on the base wall 13. The deflection device 22 allows the rotary switch 21 to be actuated by means of the drive device 23 located in the drive chamber 15 in conjunction with a drive element 26 by means of a pivoting movement. In a known manner, the drive element 26 can be introduced into the switching chamber 14 in a sealed manner by means of a bellows. If, on the other hand, the rotary movement of a switch shaft required to actuate the interrupter units of the rotary switch 21, for example,

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transmitted by means of a sealed shaft feedthrough in the bottom wall 13, the rotary switch 21 can also be arranged coaxially with the longitudinal axis of the container 7.
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Depending on the wishes of the user of the switching unit 6, the drive device 23 can be suitable for mechanical actuation by hand or for electrically controlled remote actuation. Since drive devices of this type for medium-voltage switching devices are generally known, details will not be described. However, it should be mentioned that the drive chamber 15 is closed off at the bottom by a cover 24 which has a viewing opening 25 for an optical display element of the drive device 23. By looking at the cover 24, the user standing at the foot of the mast 1 can thus determine which switching position the switching unit 6 is in.

In the example shown, manual operation is provided. For this purpose, a shaft passage 27 is arranged in the casing part 12 so that an outwardly projecting actuating shaft 28 can be actuated in a suitable manner, e.g. by means of an operating rod.

The bushings 8 shown in Figure 1 can be designed as external cone bushings, as are known for gas-insulated medium-voltage load switchgear. The bushing flanges can be welded gas-tight into the casing part 12 of the housing 7 or other sealed flange connections can be provided.

If a direct connection of the connecting conductors 10 to the bushings 8 is desired, the outer cone bushings can be equipped with a ribbed insulating adapter 30 as shown in Figure 3.

Claims (3)

Protection claims 1. Multipole switching unit mountable on a support mast (l) (6) with - a gas-tight housing (7) filled with an insulating gas, - at least one interrupter unit operating in the insulating gas for each pole, - bushings (8) arranged opposite one another on the housing (7) for connecting line sections {2, 3) to be connected by the switching unit (6), - a drive device connected to the switching unit (23) for actuating the interrupter units, - a drive element (26) passing through a wall (13) of the housing (7) in a sealed manner for connecting the drive device (23) to the interrupter units, characterized by the following features: - the housing (7) is essentially cylindrical, - the interrupter units (9) are designed as multi-pole rotary switch (21) with a common actuating shaft, and - the longitudinal axis of the rotary switch (21) is arranged approximately parallel to the longitudinal axis of the housing (7). 2. Switching unit according to claim 1, characterized in that the drive member (26) in the bottom wall (13) of the housing (7) and that the opposite roof wall (16) is provided with a protective device (17) against overpressure. 30 hen is. 3. Switching unit according to claim 2,
characterized in that a drive chamber (15) for receiving the drive device (23) is connected to the housing (7), the drive chamber (15) being connected by a 95GAO7 7 corresponding extension of a casing part (12) of the housing (7) extending between the bottom wall (13) and the roof wall (16).