Power interruption device on an electrical line comprising a vacuum bulb
The current switch design addresses unwanted current flow during line closure by using a conductive knife to open the vacuum bulb during separation and an insulating element to prevent current flow during closure, ensuring reliable and environmentally friendly current interruption in high- and medium-voltage power lines.
Patent Information
- Application Number
- FR2021013376
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-12-13
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2041-12-13
AI Technical Summary
Existing high- and medium-voltage power line switches using vacuum lamps face issues with unwanted current flow during line closure due to degradation of surface material properties, posing a risk of damage to the vacuum tube and switch.
A current switch design featuring a movable main contact with an electrically conductive knife and an insulating element, where the conductive knife engages a vacuum bulb during opening to interrupt current without arcing, and the insulating element prevents current flow during closure by increasing isolation distances, using a bypass branch with a vacuum bulb that remains closed during closure.
Effectively prevents unwanted current flow during line closure, reducing the risk of damage to the vacuum tube and switch, while maintaining efficient current interruption and arc extinction without the use of environmentally harmful gases.
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Abstract
Description
Title of the invention: Device for cutting off current on an electrical line comprising a vacuum bulb technical field
[0001] This disclosure relates to current switches mounted on an electrical line or cable. More specifically, this disclosure relates to current switches comprising a vacuum bulb. Previous technique
[0002] A high- or medium-voltage power line is commonly equipped with a switch. The power line is designed to transmit current in a distribution network, from a voltage source to the consumer or electrical load. The switch allows the current flowing through the line to be interrupted or established by opening or closing the line.
[0003] Conventionally, the switch comprises two mutually movable contacts between a junction position, corresponding to the closure of the line, and a separation position, corresponding to the opening of the line. During the separation, the two contacts are separated in an insulating medium contained in a tank, in order to extinguish an electric arc that is established when the contacts separate.
[0004] On medium and high voltage lines, the insulating medium is commonly sulfur hexafluoride SF6. However, this gas has the disadvantage of being a greenhouse gas, the use of which in large quantities is extremely harmful to the environment.
[0005] To overcome this, there are switches equipped with vacuum lamps, in which contact separation is achieved in a vacuum. This solution makes it possible to extinguish the electric arc without the need for the use of polluting gases. However, vacuum lamps that can be integrated directly into the line are expensive, particularly because of the dimensions and materials they require to meet various electrical and dielectric requirements, such as resistance to lightning strikes or short-circuit breaking capacity.
[0006] Document EP 2 182 536 proposes mounting the vacuum lamp on a branch of a main section of the line. A disconnect switch actuates a movable end of the branch during an opening or closing stroke. During the opening stroke, the disconnect switch activates a conductive face of the movable end to allow current to flow into the branch and then open the vacuum lamp. During the closing stroke, an insulating face of the movable end is activated by the disconnect switch to prevent current from flowing into the branch and to keep the lamp closed. vacuum at rest. The vacuum bulb is left at rest when the line is closed, which allows it to be subjected to less stringent constraints and reduces the characteristics it must possess, which has a significant impact on its manufacturing cost.
[0007] However, at certain high voltage levels and with a large number of switch operations, there is a risk during line closure. When the disconnector comes into contact with the insulating face of the moving end, as described in document EP 2 182 2536, due to the degradation of the surface material properties, an unwanted current may begin and flow through the branch, which can damage the vacuum tube and the switch.
[0008] The present disclosure is intended to eliminate the risk of current passing through the branch when closing the line. Summary
[0009] A current switch is proposed arranged between a first portion of an electrical line and a second portion of an electrical line, comprising at least one main contact including an electrically conductive knife, and an electrically insulating element, the main contact being movablely mounted on the first portion of an electrical line to follow alternately: an opening stroke from a closed position in which the main contact is in electrical contact with the second portion of an electrical line to an open position in which the main contact is away from the second portion of an electrical line, and a closing stroke from said open position to said closed position; at least one branch branch including a first part electrically connected to the second portion of the line, the first part including a vacuum bulb configured to be actuated alternately between an open state and a closed state;a second part mounted movable on the first part and configured to actuate the vacuum bulb, the electrically conductive knife and the electrically insulating element being configured so that: during the opening stroke, the electrically conductive knife engages the second part to actuate the vacuum bulb towards the open state, and during the closing stroke, the electrically insulating element engages the second part without actuating the vacuum bulb. ;
[0010] Thus, during a separating stroke, the main contact can actuate the moving part while remaining in electrical contact with the branch, to open the vacuum bulb and ensure current interruption without generating an electric arc. During the closing stroke, the main contact can touch the moving part without being in electrical contact with the branch, thus preventing unwanted current flow in the branch. In particular, thanks to the electrically insulating element, the isolation distances (air clearance and creepage distance) between the knife and the moving part of the branch are increased.
[0011] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other: - the electrical insulating element is a support element for the electrically conductive knife; - the electrical insulating element comprises: a body forming a housing for the knife of the main contact, a free end of the electrically conductive knife protruding from the body; and a protrusion extending from the body, said protrusion being arranged to come into contact with said second part during the closing stroke; - the protrusion extends along a plane that is axially offset from a general plane of extension of the electrically conductive knife; - the protuberance is an integral part of the body; - the protuberance is an added part on the body; - the second part comprises an electrically conductive face and an electrically insulating face, the electrically conductive face and the conductive insulating face being opposite each other; - the second part comprises a first arm mounted movably on the first part, and a second arm mounted movably on a free end of the first arm;
[0012] - the second arm includes an outgrowth adapted to come into contact with the electrical insulating element during the closing stroke; - the branch branch further includes a stop adapted to maintain the second arm in a stop position in which the second arm extends in line with the first arm during the opening stroke; - the second arm is made of electrically conductive material; - the main contact is mounted pivotally on the first portion of the line along a first pivot axis, the second part of the branch being mounted pivotally on the first part of the branch along a second pivot axis, the first pivot axis being parallel to the second pivot axis; - the bypass branch includes a spring mounted between the first part and the second part, the spring being adapted to force the second part towards a rest position, in which the vacuum bulb is in the closed state; - the main contact is also adapted to follow an earthing stroke from the open position to an earthing position, the knife of the main contact being in electrical contact with an earthing electrode when the main contact is in said earthing position.
[0013] According to another aspect, a three-phase switching device comprising at least one switch is proposed. Brief description of the drawings
[0014] Other features, details and advantages will become apparent upon reading the detailed description below and analyzing the accompanying drawings, in which: Fig. 1
[0015] [Fig.1] represents a side view of a switch on a portion of an electrical line in a closed position, according to one embodiment. Fig. 2
[0016] [Fig.2] represents a side view of a detail of [Fig.1] during a closing stroke, according to one embodiment. Fig. 3
[0017] [Fig.3] represents a perspective view of [Fig.2], according to one embodiment. Fig. 4
[0018] [Fig.4] schematically represents a side view of the switch of [Fig.1] in a closed position, according to one embodiment. Fig. 5
[0019] [Fig.5] schematically represents a side view of the switch of [Fig.1] during a switching phase of the separation stroke, according to one embodiment. Fig. 6
[0020] [Fig.6] schematically represents a side view of the switch of [Fig.1] during a current cut-off phase of the separation stroke, according to one embodiment. Fig. 7
[0021] [Fig.7] schematically represents a side view of the switch of [Fig.1] in an open position, according to one embodiment. Fig. 8
[0022] [Fig.8] schematically represents a side view of the switch of [Fig.1] during a closing stroke engagement phase, according to one embodiment. Fig. 9
[0023] [Fig.9] schematically represents a side view of the switch of [Fig.1] in a phase of restoring the current of the closing stroke, according to one embodiment. Fig. 10
[0024] [Fig. 10] schematically represents a side view of the switch in [Fig. 1] in a grounding position, according to one embodiment. Description of the implementation methods
[0025] In the different figures, the same references designate identical or similar elements.
[0026] Figure 1 illustrates a switch 10 mounted in a medium- or high-voltage line. In what follows, the terms "medium voltage" and "high voltage" are used in their usual sense, namely that "medium voltage" refers to a voltage that is greater than 1,000 volts AC and 1,500 volts DC but does not exceed 52,000 volts AC and 75,000 volts DC, while "high voltage" refers to a voltage that is strictly greater than 52,000 volts AC and 75,000 volts DC. Such a power line is intended to transmit current in a distribution network.
[0027] It should be noted that such a high- or medium-voltage power line generally comprises three phases, i.e., it is three-phase. Thus, the line may include three switches 10 as described below. Each switch 10 may be associated with one of the phases of the power line. The switches 10 may be housed in a sealed enclosure or tank, in particular one containing pressurized air, which allows for an economical and compact arrangement of the switches 10.
[0028] The switch 10 is mounted between a first portion 12 of the line and a second portion 14 of the line. In the illustrated example, the first portion 12 extends to a point of consumption, and the second portion 14 returns to a voltage source. The point of consumption could, for example, be a public distribution substation or an industrial installation. Alternatively, the second portion 14 could return to the point of consumption, and the first portion 12 could extend to the voltage source. Alternatively still, the second portion 12 could be connected to the first portion 14, forming an open-loop distribution network. The switch 10 can close the line, allowing current to flow between the two portions 12 and 14 of the line. The switch 10 can also open the line, interrupting the current flow between the two portions 12 and 14 of the line.
[0029] Furthermore, the switch 10 can be located near an earthing electrode 50. In addition to opening and closing the line, the switch 10 can also provide earthing for the line. Earthing contributes to the safety of personnel working on the line. The switch 10 is then a three-position switch.
[0030] The switch 10 essentially comprises a main contact 16 and a branch branch 18.
[0031] The main contact 16 is movably mounted on the first section 12 of the line. An opening stroke corresponds to the transition of the main contact 16 from a closed position to an open position. In the closed position, the main contact 16 is in electrical contact with the second section 14 of the line. The line is closed, and current can flow through the main contact 16 to reach the second section 14 of the line. Conversely, in the open position, the main contact 16 is separated from the second section 14 of the line. The line is open, and the current flow between the first section 12 and the second section 14 of the line is interrupted. Furthermore, a grounding stroke corresponds to the transition of the main contact 16 from the open position to a grounding position. In the grounding position, the main contact 16 makes contact with the grounding electrode 50.Finally, a closing stroke corresponds to the return of the main contact 16 to the closed position from the open position.
[0032] The main contact 16 is here mounted to rotate about a pivot axis A. The axis A is substantially perpendicular to the general extension plane of the main contact 16. Thus, the opening stroke corresponds to a rotation of the main contact 16 about the axis A. The grounding stroke corresponds to a continuation of the rotation of the main contact 16 about the axis A. The closing stroke corresponds to a continuation of the rotation of the first switch element 16 about the axis A, in the opposite direction to the opening stroke.
[0033] The main contact 16 is controlled by an actuator (not shown). The actuator can be positioned near the first portion 12 of the line to control the opening, closing, or grounding stroke of the main contact 16.
[0034] As illustrated in [Fig.1], the main contact 16 comprises an electrically conductive knife 20 and an electrically insulating element 22.
[0035] The electrically conductive knife 20 extends between the first and second sections of the line 12, 14 to make contact with the second section 14 of the line in the closed position, and with the grounding electrode 50 in the grounding position. The electrically conductive knife 20 is made of an electrically conductive material. The cross-section of the electrically conductive knife 20 is adapted to establish electrical contact with the second section 14 of the line or the grounding electrode 50. Furthermore, the cross-sectional area of the electrically conductive knife 20 is sufficient to support a continuous flow of current. Thus, the electrically conductive knife 20 is configured to support a continuous flow of current.
[0036] It is noted that the electrically conductive knife 20 can reach the second section 14 of the line by any means allowing electrical contact between the main contact 16 and the second section 14 of the line. Similarly, the main contact 16 can connect to the earth connection 50 by any means enabling electrical contact between the main contact 16 and the earth connection 50. For example, electrical contact can be obtained by insertion, by plugging or by pinching.
[0037] Furthermore, a free end of the electrically conductive knife 20, located away from the first portion of the line 12, is configured to drive part of the branch 18 during its opening stroke. The conductive property of the electrically conductive knife 20 allows current to flow to the branch 18.
[0038] The electrical insulating element 22 extends parallel to the electrically conductive knife 20. The electrical insulating element 22 is made of an insulating material, for example, epoxy or any other non-conductive material. Current does not flow through the electrical insulating element 22. The electrical insulating element 22 drives a portion of the bypass branch 18 during the closing stroke. The insulating property of the insulating element 22 prevents current from flowing through the bypass branch 18 during the closing stroke.
[0039] In the illustrated example, the electrical insulating element 22 comprises a body 24 and a protrusion 26.
[0040] The body 24 is a hollow part that defines a housing for the electrically conductive knife 20. The electrically insulating element 22 thus forms a support element for the electrically conductive knife 20 (also called a "lever arm"). The electrically insulating element 22 contributes to the dielectric strength between the electrically conductive knife 20 and any other potential-enabled part of the second section 14 of the line. The free end of the electrically conductive knife 20, away from the second section of the line 14, protrudes from the body 24. The electrically conductive knife 20 can then come into electrical contact with the second section of the line 14, the grounding electrode 50, and the branch 18 during the opening stroke.
[0041] The protrusion 26 extends from the body 24 in a plane substantially parallel to the free end of the electrically conductive knife 20. In this case, the protrusion 26 extends in a plane offset from the plane of extension of the electrically conductive knife 20. Specifically, the protrusion 26 lies in a plane perpendicular to the pivot axis A. Thus, the protrusion 26 can participate in the closing stroke without obstructing the electrically conductive knife 20 during the opening stroke. It should be noted that, in an embodiment not shown, a protrusion 26 could be provided on either side of the electrically conductive knife 20.
[0042] Viewed from the side, and as seen in [Fig. 2], an edge of the protrusion 26 extends beyond the electrically conductive blade 20 in the direction of the closing stroke. A distance d, measured in a plane parallel to the extension plane of the protrusion 26, between the edge of the protrusion 26 and the edge of the electrically conductive blade 20 is, for example, between 5 mm and 50 mm. The distance d allows us to define a distance The insulation distance between the electrically conductive knife 20 and the branch 18 is designed to limit the risk of current transmission between the electrically conductive knife 20 and the branch 18 during the closing stroke. The distance d increases the air insulation distance and creepage distance between the electrically conductive knife 20 and the branch 18.
[0043] It is noted that an opposite edge of the protuberance 26 is set back from the electrically conductive knife 20. In the direction of the opening stroke, the electrically conductive knife 20 extends beyond the protuberance 26. The protuberance 26 can come into contact with the branch 18 during the closing stroke and not intervene in the opening stroke.
[0044] The protrusion 26 can be an integral part of the body 24, for example, by being molded with the body 24. Alternatively, the protrusion 26 can be an added component on the body 24. The protrusion 26 can, for example, be fixed to the body 24 by means of screws. Of course, other fastening methods can be used to fix the protrusion 26 to the body 24.
[0045] The branch branch 18 essentially comprises a first part 28 and a second part 36, movablely mounted on the first part 28. The first and second parts 28, 36 are in electrical continuity.
[0046] The first part 28 is mounted on the second portion of the line 14 to be electrically continuous with the second portion of the line 14. The first part 28 comprises a vacuum bulb 30. In this case, the vacuum bulb 30 contains a pair of contacts, the first of which is attached to a fixed rod 32, connected to the second portion of the line 14, and the second of which is attached to a movable rod 34, connected to the second portion 36 of the branch 18. Thus, the vacuum bulb 30 can be actuated between an open and a closed state by a movement of the second part 36. When the bulb 30 is in the closed state, and during the opening phase when the knife 20 is in contact with the branch 18, the current can flow through the bulb 30 and reach the second portion of the line 14 via the branch 18.When bulb 30 is in the open state, current does not flow through bulb 30 and the passage of current through the bypass branch 18 is interrupted.
[0047] The second part 36 extends from the first part 28 to the second section of the line 12. In its rest position, the second part 36 is oriented towards the second section of the line 14, without touching the main contact 16. Current does not flow through the branch 18, and the vacuum bulb 30 is in the closed state. During the opening stroke, the second part 36 is driven by the electrically conductive knife 20 of the main contact 16. Current flows through the branch 18, and the movable rod 34 is moved to actuate the vacuum bulb 30 to the open state. In a first release position of the second During the opening stroke, the electrically conductive knife 20 releases the second part 36, and the electrical contact between the branch 18 and the electrically conductive knife 20 is broken without arcing. During the closing stroke, the second part 36 is driven by the electrically insulating element 22 of the main contact 16. No current flows through the branch 18 during the closing stroke. In a second release position of the second part 36, during the closing stroke, the electrically insulating element 22 releases the second part 36.
[0048] The second part 36 is here mounted for rotation on the first part 28 about a second pivot axis X. The second pivot axis X is parallel to the first pivot axis A of the main contact 16. The drive of the second part 36 thus corresponds to a rotation of the second part 36 about the second pivot axis X. The main contact 16 and the second part 36 move along substantially parallel planes, minimizing the size of the switch 10.
[0049] Furthermore, the second part 36 is attached to an elastic force 44, for example in the form of a spring 44. The elastic force 44 is mounted on one side on the first part 28 and on the other side on the second part 36 of the branch 18. The elastic force 44 forces the second part 36 towards the rest position. During the opening stroke, the main contact 16 acts against the elastic force 44, to move the second part 36 out of the rest position. In the first release position, the elastic force 44 returns the second part 36 to the rest position.
[0050] In the illustrated example, the second part 36 comprises a first arm 38, extending from the first part 28, and a second arm 40 (also called a "retractable pallet"). The first arm 38 extends from an end connected to the first part 28 to a free end. The second arm 40 is mounted partially freely movable on the free end of the first arm 38.
[0051] A stop 46 holds the second arm 40 in a stop position, in which the second arm 40 extends in line with the first arm 38. During the opening stroke, when the main contact 16 activates the second part 36 of the branch arm 18, the second arm 40 is held in the stop position and the first and second arms 38, 40 move together. Conversely, during the closing stroke, the second arm 40 is not constrained by the stop 46, and the second arm 40 can be driven by the electrically conductive knife 20 of the main contact 16 independently of the first arm 38. The main contact 16 can close the line by moving only the second arm 40, without moving the first arm 36 and therefore without actuating the vacuum bulb 30 or causing an electrical contact between the first section of line 12 and branch 18.
[0052] Furthermore, the second arm 40 can be subjected to elastic loading, for example, by a spring. The second arm 40 can be configured to hold the second arm 40 in the stop position. During the closing stroke, the main contact 16 can move the second arm 40 out of the stop position. At the second release position, during the closing stroke, the second arm 40 can be returned to the stop position by elastic loading.
[0053] Here, the second arm 40 is mounted for rotation on the first arm 38, around a third pivot axis Y. The third pivot axis Y is parallel to the first and second pivot axes A, X. During the closing stroke, the drive of the second arm 40 corresponds to a rotation of the second arm 40 around the third pivot axis Y.
[0054] The second arm 40 may include an electrically conductive face 52 and an electrically insulating face 54. The conductive face 54 faces the second portion of the line 14 to be in contact with the electrically conductive blade 20 of the main contact 16 during the opening stroke. The electrically insulating face 54 is opposite the conductive face 52, to come into contact with the electrically insulating element 22 during the closing stroke. The insulating face 54 further limits the risk of current flow between the main contact 16 and the branch arm 18 during the closing stroke. Indeed, the insulating face 54 increases the air gap and the creepage distance between the electrically conductive blade 20 and the conductive face 52.
[0055] The second arm 40 may be made of an electrically conductive material. The insulating face 54 may be formed by coating it with an insulating material. Alternatively, the second arm 36 may be made of a non-electrically conductive material. The conductive face 52 may be formed by coating it with a conductive material or by a braid extending along the second arm 40.
[0056] Furthermore, the second arm 40 here includes an outgrowth 42 disposed near a free end of the second arm 40. The outgrowth 42 faces the protrusion 26 of the electrical insulating element 22, to interact, in particular by cam effect, with the electrical insulating element 22 during the closing stroke.
[0057] Alternatively, the second part 36, and in particular the second arm 40 of the second part 36, may be made entirely of electrically conductive material. This embodiment particularly facilitates the manufacture of the switch 10.
[0058] The operation of the switch 10 is described in more detail below, with reference to Figures 4 to 10. Figures 4 to 10 represent a simplified and schematic view of the operation of the switch 10 according to one embodiment.
[0059] A separation stroke corresponds to the transition of the main contact 16 from the closed position to open position.
[0060] As shown in [Fig. 4], the main contact 16 is initially in the closed position. Current flows through the electrically conductive blade 20 of the main contact 16. The second part 36 is in its rest position, oriented towards the second portion of the line 14 without touching the main contact 16. Current does not flow through the branch 18, despite the closed state of the vacuum bulb 30.
[0061] During a current switching phase, illustrated in [Fig. 5], the main contact 16 begins to move. The free end of the electrically conductive knife 20 comes into contact with the second part 36 of the branch 18 while remaining connected to the second portion of the line 14. The current reaches the second portion of the line 14 via two parallel circuits: directly through the electrically conductive knife 20 and through the electrically conductive knife 20 and the branch 18. During the switching phase, the contacts are at the same electrical potential, and no electric arc is formed.
[0062] During a switching phase, illustrated in [Fig. 6], the electrically conductive knife 20 of the main contact 16 is separated from the second portion of the line 14. The current returns to the second portion of the line 14 via the branch 18, passing through the vacuum tube 30. The free end of the electrically conductive knife 20 drives the second portion 36, whose movement causes the vacuum tube 30 to open. The current is interrupted in the vacuum tube 30, preventing the formation of an electric arc between the knife 20 and the second portion of the line 14 during the opening stroke. An electric arc can indeed form in the vacuum tube 30.
[0063] In the first release position, the electrically conductive knife 20 of the main contact 16 releases the second part 36 of the branch 18. The vacuum bulb 30 is in the open state, so no current flows through the line. The main contact 16 can continue rotating to the open position, and the spring 44 can return the second part 36 to its rest position, thus closing the vacuum bulb 30.
[0064] In the open position, illustrated in [Fig. 7], the main contact 16 is separated from the second portion of the line 14. Current does not flow through the line. The second part 36 of the branch 18 is in the rest position, and the vacuum bulb 30 is in the closed state.
[0065] The closing stroke corresponds to the transition of the main contact 16 from the open position to the closed position.
[0066] In an engagement phase, illustrated in [Fig. 8], the electrically insulating element 22 comes into contact with the second part 36 of the branch arm 16. The current does not flow through the branch arm 18. The second arm 40 of the second part 36 is driven independently of the first arm 38. Thus, the vacuum bulb 30 is maintained in the closed state. In this case, the isolation distance between the electrically conductive knife 20 of the main contact 16 and all parts of the branch 18 at the potential of the second line portion 14 is sufficient to prevent the formation of an arc between the main contact 16 and the branch 18 during the closing stroke.
[0067] During a current restoration phase, illustrated in [Fig.9], the electrically conductive knife 20 of the main contact 16 joins the second portion of the line 14. The current can join the second portion of the line 14 via the electrically conductive knife 20, without passing through the branch branch 18.
[0068] In the second release position, the main contact 16 releases the second arm 40 of the second part 36 of the branch branch 18. The second arm 40 of the second part 36 returns to the stop position, in particular under the effect of the elastic force acting on the second arm 40. The switch 10 is again in the closed position of [Fig.4].
[0069] The grounding stroke corresponds to the transition of the main contact 16 from the open position to grounding. As shown in [Fig. 10], the grounding stroke corresponds to a continuation of the rotation of the main contact 16 until it makes electrical contact with the ground electrode 50.
Claims
Demands
1. Current switch (10) arranged between a first portion of power line (12) and a second portion of power line (14), comprising: - at least one main contact (16) comprising an electrically conductive knife (20) and an electrically insulating element (22), the electrically insulating element (22) being a support element for the electrically conductive knife (20), the main contact (16) being movably mounted on the first portion of the power line (12) to follow alternately: • an opening stroke from a closed position in which the main contact (16) is in electrical contact with the second portion of the power line (14) to an open position in which the main contact (16) is away from the second portion of the power line (14), and • a closing stroke from said open position to said closed position; - at least one branch (18) comprising a first part (28) electrically connected to the second portion of the line (14), the first part comprising a vacuum bulb (30) configured to be operated alternately between an open state and a closed state, and a second part (36) movably mounted on the first part (28) and configured to operate the vacuum bulb (30), the electrically conductive knife (20) and the electrically insulating element (22) being configured such that: - during the opening stroke, the electrically conductive knife (20) engages the second part (36) to actuate the vacuum bulb (30) towards the open state, and - during the closing stroke, the electrical insulating element (22) stresses the second part (36) without actuating the vacuum bulb (30).
2. Switch (10) according to claim 1, wherein the insulating element electrical (22) comprises: - a body (24) forming a housing for the knife (20) of the main contact (16), a free end of the electrically conductive knife (20) protruding from the body (24); and - a protrusion (26) extending from the body (24), said protrusion (26) being arranged to come into contact with said second part (36) during the closing stroke.
3. Switch according to claim 2, wherein the protrusion (26) extends along a plane offset axially from a general extension plane of the electrically conductive knife (20).
4. Switch (10) according to any one of claims 2 to 3, wherein the protrusion (26) is an integral part of the body (24).
5. Switch (10) according to any one of claims 2 to 3, wherein the protrusion (26) is an added part on the body (24).
6. Switch (10) according to any one of the preceding claims, wherein the second part (36) comprises an electrically conductive face (52) and an electrically insulating face (54), the electrically conductive face (52) and the conductive insulating face (54) being opposite each other.
7. Switch (10) according to any one of the preceding claims, wherein the second part (36) comprises: - a first arm (38) movably mounted on the first part (28), and - a second arm (40) movably mounted on a free end of the first arm (38).
8. Switch (10) according to claim 7, wherein the second arm (40) includes a protrusion (42) adapted to come into contact with the electrical insulating element (22) during the closing stroke.
9. Switch (10) according to claim 7 or 8 wherein the branch arm (18) further comprises a stop (46) adapted to hold the second arm (40) in a stop position in which the second arm (40) extends in line with the first arm (38) during the opening stroke.
10. Switch (10) according to any one of claims 7 to 9, wherein the second arm (40) is made of electrically conductive material.
11. A switch (10) according to any one of the preceding claims, wherein the main contact (16) is pivotally mounted on the first portion of the line (12) about a first pivot axis (X), the second portion (36) of the branch branch (18) being mounted pivoting on the first part (28) of the branch of derivation (18) along a second pivot axis (A), the first pivot axis (X) being parallel to the second pivot axis (A).
12. Switch (10) according to any one of the preceding claims, wherein the bypass branch (18) comprises a spring (44) mounted between the first part (28) and the second part (36), the spring (44) being adapted to strain the second part (36) towards a rest position, in which the vacuum bulb (30) is in the closed state.
13. Switch (10) according to any one of the preceding claims, wherein the main contact (16) is also adapted to follow a grounding stroke from the open position to a grounding position, the knife (20) of the main contact (16) being in electrical contact with a grounding electrode (50) when the main contact (16) is in said grounding position.
14. Three-phase switching device comprising at least one switch (10) according to any one of the preceding claims.