Switch for a load tap changer and load changeover switch for a load tap changer

Abstract

The invention relates to a switch for an on-load tap changer of a tap-changing transformer, comprising: a discharge contact; a primary fixed contact; and at least one contact unit, which has a movable contact, a first erosion contact and a second erosion contact, which movable contact and first and second erosion contacts can be pivoted, during a switching process of the switch, about a pivot axis in such a way that they can each assume a first position, in which they contact the discharge contact and the primary fixed contact, and a second position, in which they are separated from the discharge contact and the primary fixed contact. During the switching from the second position to the first position, the second erosion contact assumes the first position before the first erosion contact. And during the switching from the first position to the second position, the second erosion contact leaves the first position after the first erosion contact.

Description

[0001] The invention relates to a switch for an on-load tap changer of a tapped transformer and a load diverter switch for an on-load tap changer of a tapped transformer.

[0002] German patent application DE 10 2014 107 273 A1 discloses a switch for a diverter switch of an on-load tap-changer with a discharge contact, a primary fixed contact, and several primary moving contacts arranged in a stack in a contact carrier. The switch also includes two identically constructed primary arcing contacts.

[0003] Common on-load tap-changers typically consist of a selector for powerless selection of the respective transformer winding tap to which switching is to take place, and a load transfer switch for the actual load transfer from the previous winding tap to the new, selected winding tap. Switching is performed by operating various switches. This regularly creates arcs at the switching contacts, which melt or burn small amounts of the contact material, thus leading to contact erosion. The erosion depends on the current strength and the duration of the arc at the respective contact. As the load increases, i.e., higher currents and voltages, the demands on the switches and contacts also increase.

[0004] The document WO 2017 / 036496 A1 discloses a switch for an on-load tap changer of a tapped transformer, according to the preamble of patent claim 1.

[0005] It is therefore an object of the present invention to provide an improved switch for an on-load tap changer and an improved load diverter switch for a tap changer which can withstand the increased loads at higher currents and voltages.

[0006] This object is achieved by the respective subject matter of the independent claims. Further embodiments are the subject matter of the dependent claims.

[0007] According to a first aspect of the invention, the aforementioned object is achieved by a switch having the features of claim 1. A switch is therefore provided for or in an on-load tap changer of a tapped transformer. The switch comprises a shunt contact, a primary fixed contact, and at least one contact unit. The contact unit has at least one movable contact, a first arcing contact, and a second arcing contact, which, during a switching operation of the switch, can be pivoted together about a pivot axis such that they can each assume a first position in which they contact the shunt contact and the primary fixed contact, and a second position in which they are separated from the shunt contact and the primary fixed contact.When switching the contact unit from the second position to the first position, the second arcing contact takes the first position before the first arcing contact and when switching from the first position to the second position, the second arcing contact leaves the first position after the first arcing contact.

[0008] The sequential entry and exit of the first position by the first and second arcing contacts causes the current to be switched off to be "transferred" from one arcing contact to the other. In technical terms, this process is also called "commutation." More generally, "commutation" refers to the transfer of current from one current branch to another, with both branches carrying current during the commutation time.

[0009] According to at least one embodiment, when switching the contact unit from the second position to the first position, the first erosion contact assumes the first position in front of the at least one movable contact and when switching from the first position to the second position, the first erosion contact leaves the first position after the at least one movable contact.

[0010] In this way, an additional commutation stage is created and the duration of the arc and the contact erosion on the moving contact and the erosion contacts are further reduced.

[0011] This multi-stage commutation has the advantage that the duration of an arc at the first and second arcing contacts or the moving contact is shortened, and thus the contact erosion at the first and second arcing contacts or the moving contact is also reduced.

[0012] According to at least one embodiment, the movable contact, the first erosion contact and the second erosion contact are made of different conductive materials having different conductivities.

[0013] Preferably, the movable contact is made of copper, the first consumable contact is made of brass and the second consumable contact is made of stainless steel.

[0014] The choice of material can influence contact erosion due to its properties. It is particularly important that the contacts erosion evenly, so that the staggered contact and lifting times, as well as the sequence of contact and lifting of the moving contact, the first erosion contact, and the second erosion contact, are maintained. Otherwise, faults and malfunctions can occur in the switch and, consequently, in the entire on-load tap-changer.

[0015] According to at least one embodiment, the movable contact and / or the first erosion contact and / or the second erosion contact have a different geometric shape.

[0016] In particular, by providing recesses in a consumable contact and / or a movable contact, the cross-section through which the current flows can be reduced. This has the advantage that the electrical conductivity of the consumable contacts and / or the movable contact can be further adjusted, if necessary, via the geometric shape of the contacts to achieve uniform consumption.

[0017] According to at least one further embodiment, the at least one movable contact, the first erosion contact and the second erosion contact each have two contact areas with which they rest on the discharge contact and the associated fixed contact in the first position.

[0018] At least one of the two contact areas may be made of a material different from the material of the rest of the contact, for example an arc-resistant copper-tungsten sintered material.

[0019] According to at least one embodiment, the first erosion contact and the second erosion contact are arranged in the second position relative to the movable contact such that at least one contact region of the first erosion contact and / or the second erosion contact protrudes relative to the contact regions of the movable contact.

[0020] According to at least one embodiment, the second erosion contact is arranged in the second position relative to the first erosion contact such that at least one contact area of the second erosion contact protrudes relative to the contact areas of the first erosion contact.

[0021] A contact area that protrudes relative to the other contact areas causes the corresponding contact to contact the shunt contact and / or the primary fixed contact earlier when switching to the first position than contacts that have no or a less protruding contact area. Conversely, the contact also leaves the shunt contact and / or the primary fixed contact later when switching from the first position to the second position. This can influence the duration of an arc at a contact and the contact erosion.

[0022] According to at least one embodiment, the switch comprises a contact carrier pivotably mounted about the pivot axis, comprising a first support plate and a second support plate arranged parallel to the first support plate. Furthermore, the contact carrier comprises at least one further movable contact, wherein the movable contacts, the first arcing contact, and the second arcing contact are arranged between the support plates. The movable contacts are preferably identical in shape and material.

[0023] According to at least one embodiment, the movable contacts, the first erosion contact, and the second erosion contact are arranged in a stack in the contact carrier. For fastening in the contact carrier, the movable contacts, the first erosion contact, and the second erosion contact each have two parallel, superimposed elongated holes. They are movably mounted between the support plates by means of guide bolts that pass through the elongated holes.

[0024] The movable contacts, the first erosion contact and the second erosion contact can be arranged in a stack spaced from one another by discs that are located between the individual contacts and pushed onto the guide pins.

[0025] According to at least one embodiment, the guide pins together with the elongated holes form a mechanical stop for the movable contacts and the first and second arcing contacts during the switching operation of the switch against the force exerted on these contacts by compression springs arranged on the back surfaces of the contacts facing away from the contact areas.

[0026] According to at least one embodiment, the elongated holes of the movable contacts, the first erosion contact, and the second erosion contact are each configured with different lengths, such that the movable contacts, the first erosion contact, and the second erosion contact reach the mechanical stop at different times during the switching process of the switch or contact unit from the second to the first position and / or from the first to the second position. It can be provided that the elongated holes of the first erosion contact are shorter than the elongated holes of the second erosion contact and longer than the elongated holes of the movable contacts.

[0027] In the second position, the movable contacts as well as the first and second arcing contacts each rest against the guide pins with the ends of the elongated holes facing away from the contact areas. This can cause the second arcing contact to protrude further beyond the guide pins than the first, which in turn protrudes further than the movable contacts. As a result, the movable contacts, the first arcing contact, and the second arcing contact reach the shunt contact and the primary fixed contact one after the other when the switch or contact unit switches from the second to the first position, and they also leave the shunt contact and the primary fixed contact one after the other when the switch is switched from the first to the second position.

[0028] According to at least one embodiment, the movable contacts, the first erosion contact and the second erosion contact are arranged on the contact carrier such that they are resiliently preloaded against the discharge contact and the primary fixed contact in the first position.

[0029] According to at least one embodiment, the movable contacts, the first arcing contact, and the second arcing contact are arranged in a stack such that the movable contacts are arranged between the first arcing contact and the second arcing contact. In principle, however, any arrangement of the contacts in a stack is possible.

[0030] According to at least one embodiment, the switch comprises a secondary fixed contact and a second contact unit which is arranged symmetrically to the first contact unit with respect to an axis of symmetry which runs through the pivot axis.

[0031] The second contact unit is constructed analogously to the first contact unit and therefore has a third arcing contact, which is identical to the first arcing contact, and a fourth arcing contact, which is identical to the second arcing contact. The fourth arcing contact is on the same plane as the first arcing contact, and the third arcing contact is on the same plane as the second arcing contact.

[0032] According to at least one embodiment, the switch is designed as a permanent main switch or as a disconnector for or in a load transfer switch of an on-load tap changer.

[0033] According to a second aspect of the invention, the object mentioned above is achieved by a load diverter switch for or in an on-load tap changer of a tapped transformer. The load diverter switch has a switch designed according to the first aspect of the invention with at least one contact unit. Furthermore, the load diverter switch has a first current path comprising the movable contacts of the contact unit of the switch, a second current path comprising the first arcing contact of the switch, a third current path comprising the second arcing contact of the switch, a fourth current path comprising at least one vacuum interrupter, and a fifth current path connecting the switch to a downstream line.

[0034] The first current path has a specific resistance, which results from the specific resistance of the material from which the moving contacts are made. The second current path has a resistance that is greater than the resistance of the first current path, and the third current path has a resistance that is greater than the resistance of the second current path. By designing the resistances of the current paths according to the described procedure, low and largely uniform wear of the switch contacts is achieved during multi-stage commutation of the load current.

[0035] According to a preferred embodiment, the resistances of the second and third current paths can be determined by the material of the respective erosion contact or the specific resistance of the material from which the respective erosion contact, which is a component of the path, consists and / or by the geometric shape of this erosion contact.

[0036] The resistance of the fourth current path sometimes results from the material of the contacts or the specific resistance of the material of the contacts of the at least one vacuum interrupter that the fourth current path comprises.

[0037] The resistance of the fifth current path results from the material of the wire or the specific resistance of the material of which the wire is made, which connects the switch to the downstream line.

[0038] According to a preferred embodiment, the load changeover switch comprises a switch with a second contact unit, wherein the load changeover switch has at least three further current paths which comprise the movable contacts of the second contact unit as well as a third erosion contact and a fourth erosion contact of the second contact unit and which are designed analogously to the first, second and third current paths.

[0039] According to a further preferred embodiment, the load changeover switch has a switch with a second contact unit, wherein the load changeover switch has five further current paths which are designed analogously to the first, second, third, fourth and fifth current paths.

[0040] Further features, advantages, and possible applications of the present invention will become apparent from the following description of the exemplary embodiments and the figures. All described and / or illustrated features, individually and in any combination, constitute the subject matter of the invention, regardless of their composition in the individual claims or their references.

[0041] Components that are identical, functionally identical, or have an identical effect may be provided with identical reference numerals. Identical components or components with identical functions may only be explained in the figure in which they first appear. The explanation is not necessarily repeated in subsequent figures.

[0042] It shows Figure 1 shows a perspective view of an advantageous embodiment of a switch for an on-load tap-changer; Figure 2 shows a plan view of an advantageous embodiment of a load diverter switch for an on-load tap-changer, which switches the Figure 1 Figure 3 shows a partial sectional view of the switch from Figure 1 ; Figure 4 shows a schematic representation of an advantageous embodiment of a load diverter switch; Figure 5 shows a plan view of a further advantageous embodiment of the load diverter switch.

[0043] In the Figure 1 a perspective view of an advantageous embodiment of a switch 10 for an on-load tap changer 40 is shown.

[0044] In this embodiment, the switch 10 comprises a shunt contact 13, a primary fixed contact 14, and a secondary fixed contact 15. The switch 10 further comprises a first contact unit 12, which is located in a first position in which it contacts the shunt contact 13 and the primary fixed contact 14, and a second contact unit 37, which is located in a second position in which it is separated from the shunt contact 13 and the secondary fixed contact 15. The contact units 12, 37 are arranged in a contact carrier 20 and are pivotably mounted relative to the shunt contact 13 and the fixed contacts 14, 15 about a pivot axis 21 such that they can each assume the first position and the second position. The first contact unit 12 comprises a contact stack with a first arcing contact 17, a second arcing contact 18 and a plurality of movable contacts 16 arranged between the arcing contacts 17 and 18.The second contact unit 37 also comprises a contact stack with a third arcing contact 38, a fourth arcing contact 39, and several movable contacts 16 located between the arcing contacts 38 and 39. The discharge contact 13, the fixed contacts 14, 15, and the movable contacts 16, which are structurally identical to one another, are made of copper. The first and third arcing contacts 17, 38 are structurally identical to one another and are made of brass. The second and fourth arcing contacts 18, 39 are also structurally identical to one another and are made of stainless steel.

[0045] The contact carrier 20 has a first support plate 201 and a second support plate 202, between which the contact stacks of the two contact units 12 and 37 are arranged. The support plates 201, 202 are identical in construction, arranged parallel and flush one above the other, and are made of metal. The consumable contacts 17, 18, 38, 39 each have contact areas 23 with which they rest against the discharge contact 13 and one of the fixed contacts 14 and 15 in the first position. With the second contact unit 37 in the second position, it can be seen that the outer contact areas 23, relative to the pivot axis 21, are at a greater distance from the fixed contacts 14 and 15 than the inner contact areas 23 are from the discharge contact 13.

[0046] Figure 2 shows a plan view of an advantageous embodiment of a load diverter switch 30 for an on-load tap changer 40, which replaces the switch 10 from Figure 1Here, the contact unit 37 is in the first position and the contact unit 12 is in the second position. The support plate 201 is in Figure 2 hidden so that the internal structure of the contact carrier 20 is visible. The two contact units 12 and 37 are arranged symmetrically to one another in the contact carrier 20 with respect to an axis of symmetry 22.

[0047] In this embodiment, the on-load tap-changer 40 comprises the load diverter switch 30, a switching shaft 41 for driving the switch 10, and a contact cylinder 44 through which the switching shaft 41 extends coaxially. The diverter contact 13 and the fixed contacts 14, 15 are guided through the contact cylinder 44 and secured thereto. The contact carrier 20 comprises a lever 50 with Y-shaped arms 501, 502, 503 and a fork 51. The lever 50 is arranged between the support plates 201, 202 and secured thereto by a plurality of bolts that pass through the free ends of the lateral arms 501, 502 and a central portion of the central arm 503. The fork 51 is attached to the lever 50 between the two lateral arms 501, 502 on the side facing away from the central arm 503 and has an elongated hole which runs in extension of the central arm 503 and is open at its outer end remote from the lever 50.The contact stacks 16 / 17 / 18 and 16 / 38 / 39 are each movably mounted on the support plates 201, 202 by two metal guide pins 32, which extend through parallel elongated holes 31 in the contact stacks 16 / 17 / 18, 16 / 38 / 39. The free end of the middle arm 503 is pivotally mounted about the pivot axis 21. Thus, the support plates 201, 202 and consequently also the contact carrier 20, the fork 51, and the contact stacks 16 / 17 / 18, 16 / 38 / 39 are pivotally mounted about the pivot axis 21 relative to the discharge contact 13 and the fixed contacts 14, 15. The contact stacks 16 / 17 / 18, 16 / 38 / 39 and the contact carrier 20 thus form a one-sided lever with respect to the pivot axis 21.

[0048] The contact stacks 16 / 17 / 18, 16 / 38 / 39 are arranged symmetrically to the lever 50 on both sides of the middle arm 503 and are supported with their back surfaces facing away from the contact areas 23 via compression springs ( Figure 3) on the lateral arms 501, 502. As a result, the contact stacks 16 / 17 / 18, 16 / 38 / 39 are attached to the contact carrier 20 in such a way that, in their first position, they are each resiliently preloaded against the discharge contact 13 and the associated fixed contact 14, 15.

[0049] The guide bolts 32 together with the elongated holes 31 form a mechanical stop for the movable contacts 16 and the first, second, third and fourth arcing contacts 17, 18, 38, 39 during the switching process of the switch 10, i.e. during the pivoting movement of the contact stacks 16 / 17 / 18, 16 / 38 / 39, with respect to the force acting on them by the compression springs ( Figure 3) exerted force. The elongated holes 31 of the movable contacts 16, those of the first and third erosion contacts 17, 38 and those of the second and fourth erosion contacts 18, 39 each have different lengths. The elongated holes of the second and fourth erosion contacts 18, 39 are the longest. In concrete terms, this means that when the first contact stack 16 / 17 / 18 switches from the second to the first position, the second erosion contact 18 is the last contact in the contact stack 16 / 17 / 18 to reach the shunt contact 13 and the primary fixed contact 14, and when the first position is switched from the first position to the second position, it is the last contact in the contact stack 16 / 17 / 18 to leave the shunt contact 13 and the primary fixed contact 14. The elongated holes of the first and third erosion contacts 17, 38 are shorter than the elongated holes of the second and fourth erosion contacts 18, 39 and longer than the elongated holes of the movable contacts 16.This means specifically that when the first contact stack 16 / 17 / 18 switches from the second to the first position, the first arcing contact 17 reaches the shunt contact 13 and the primary fixed contact 14 after the second arcing contact 18 and before the moving contacts 16, and leaves again after the moving contacts 16 but before the second arcing contact 18.

[0050] The load diverter switch 30 further comprises a base plate 45 of a frame (not shown in detail), a triangular driver 42, and a drive roller 43. The switching shaft 41 and the lever 50 are rotatably mounted on the base plate 45. The driver 42 is seated non-rotatably on the switching shaft 41 and carries the drive roller 43 in one corner. The drive roller 43 is slidably seated in the elongated hole of the fork 51, so that a rotation of the switching shaft 41 via the driver 42, the drive roller 43, and the fork 51 pivots the lever 50 in the opposite direction about the pivot axis 21, and this pivoting movement is transmitted via the plurality of bolts, the support plates 201, 202, and the four guide bolts 32 to the contact stacks 16 / 17 / 18, 16 / 38 / 39.

[0051] In Figure 2the load changeover switch 30 is in a stationary position in which the driving roller 43 is located at the outer end of the elongated hole of the fork 51. The driving roller 43 presses the contact stack 16 / 38 / 39 against the discharge contact 13 and the fixed contact 15 via the two guide pins 32 assigned to it. The mechanical stop formed by the elongated holes 31 and the guide pins 32 for the movable contacts 16 and the arcing contacts 38 and 39 on the side facing the discharge contact 13 and the fixed contact 15 is reached. The contact stack 16 / 17 / 18, separated from the discharge contact 13 and the fixed contact 14, is held in place by the compression springs assigned to it ( Figure 3 ) is pressed against the two guide pins 32 assigned to it. Thus, the movable contacts 16 are electrically connected to each other and to the arcing contacts 17, 18. The same applies analogously when the contact stack 16 / 38 / 39 is separated from the arcing contact 13 and the fixed contact 15.

[0052] The contact stacks 16 / 17 / 18, 16 / 38 / 39 are arranged symmetrically to the lever 50 on both sides of the middle arm 503 such that the fourth arcing contact 39 is level with the first arcing contact 17 and the third arcing contact 38 is level with the second arcing contact 18. The second and fourth arcing contacts 18, 39 have a plurality of recesses 52 in the stainless steel contact carrier, similar to a honeycomb structure, which increases the resistance of the arcing contacts or decreases the electrical conductivity.

[0053] Figure 3 shows a partial sectional view of the switch 10 from the Figures 1 and 2, in particular the contact stack 16 / 17 / 18 of the contact unit 12 in the area located outside the pivot axis 21. The figure shows the contact stack 16 / 17 / 18 in the second position on the left and in the first position on the right. The compression springs 46 are arranged between the rear surfaces of the first arcing contact 17, the second arcing contact 18 and the movable contacts 16 and the lateral arm 501. On the left side, the guide pin 32 rests against the elongated holes 31 of the contacts on the side facing away from the fixed contact 14, and on the right side, the guide pin 32 rests against the elongated holes 31 of the contacts on the side facing the fixed contact 14. On both sides it can be seen that the elongated hole 31 of the second erosion contact 18 is the longest and the elongated hole 31 of the first erosion contact 17 is shorter than that of the first erosion contact 18, but longer than the elongated hole of the movable contacts 16.

[0054] In the second position, shown on the left, the compression springs 46 press the contact stack 16 / 17 / 18 against the guide pin 32. Due to the different lengths of the elongated holes 31, the contact area 23 of the second arcing contact protrudes from the contact areas 23 of the first arcing contact 17 and the movable contacts 16. The contact area 23 of the first arcing contact 17 protrudes from the contact areas 23 of the movable contacts 16.

[0055] The contact stack 16 / 38 / 39 (in Figure 3 not shown) is constructed analogously except for the first and second erosion contacts 38 and 39, which are arranged interchangeably with respect to the contact stack 16 / 17 / 18.

[0056] Figure 4 shows a schematic representation of an advantageous embodiment of a load changeover switch 30. The load changeover switch 30 has a switch 10 with at least one contact unit 12, which according to the Figures 1 to 3can be formed, and five current paths, wherein the number of current paths in the load changeover switch 30 is not limited to five. A first current path 61, which comprises the movable contacts 16 of the contact unit 12 and has a first resistor R1 and a first impedance L1, a second current path 62, which comprises the first arcing contact 17 of the contact unit 12 and has a second resistor R2 and a second impedance L2, a third current path 63, which comprises the second arcing contact 18 of the contact unit 12 and has a third resistor R3 and a third impedance L3, a fourth current path 64, which comprises a vacuum interrupter 19 and has a fourth resistor R4 and a fourth impedance L4, and a fifth current path 65, which connects the switch 10 to a downstream line 60 and has a fifth resistor R5 and a fifth impedance L5.

[0057] Figure 5shows a plan view of a further advantageous embodiment of the load diverter switch 30. This embodiment is similar to the embodiments described with reference to Figures 1 and 2, so that the differences will be explained in more detail below.

[0058] In this embodiment, the load diverter switch 30 has three sectors, each with a switch 10. With regard to the switches 10, reference is made analogously to the previous explanations. A driver roller 43 is arranged in each corner of the driver 42. The three driver rollers 43 and the three switches 10 are arranged offset by 120° around the switching shaft 41 and are actuated synchronously by rotating the switching shaft 41.

[0059] It is believed that the present disclosure and many of its attendant advantages will be understood from the foregoing description. The described embodiment is merely illustrative, and such modifications are intended to be encompassed by the following claims. It is further understood that the invention is defined by the following claims. REFERENCE SYMBOL

[0060] 10Switch 12Contact unit 13Discharge contact 14Primary fixed contact 15Secondary fixed contact 16Moving contacts 17First arcing contact 18Second arcing contact 19Vacuum interrupter 20Contact carrier 201First support plate 202Second support plate 21Pivoting axis 22Symmetry axis 23Contact areas 30Diverter switch 31Elongated holes 32Guide bolts 37Second contact unit 38Third arcing contact 39Fourth arcing contact 40On-load tap-changer 41Switching shaft 42Driver 43Drive roller 44Contact cylinder 45Base plate 46Compression springs 50Lever 501 / 502 / 503Arms of lever 50 51Fork 52Recesses 60Discharge 61First current path 62Second current path 63Third current path 64Fourth current path 65Fifth current path R1, R2, R3, R4, R5Resistances from 61 to 65 L1, L2, L3, L4, L5Impedances from 61 to 65

Claims

1. A switch (10) for an on-load tap-changer (40) of a tapped transformer, comprising - a take-off contact (13); - a primary fixed contact (14); - at least one contact unit (12) which has a moving contact (16), a first arcing contact (17) and a second arcing contact (18) which, during a switching operation of the switch (10), can be pivoted about a pivot axis (21) in such a way that they can each assume a first position in which they contact the take-off contact (13) and the primary fixed contact (14) and a second position in which they are separated from the arcing contact (13) and the primary fixed contact (14); characterized in that - when switching from the second position to the first position, the second arcing contact (18) assumes the first position before the first arcing contact (17) and leaves the first position after the first arcing contact (17) when switching from the first position to the second position.

2. Switch (10) according to the preceding claim, wherein - when switching from the second position to the first position, the first arcing contact (17) assumes the first position before the moving contact (16) and leaves the first position after the moving contact (16) when switching from the first position to the second position.

3. Switch (10) according to one of the preceding claims, wherein - the moving contact (16), the first burn-off contact (17) and the second burn-off contact (18) are made of different materials which have different electrical conductivity.

4. Switch (10) according to one of the preceding claims, wherein - the moving contact (16) and / or the first arcing contact (17) and / or the second arcing contact (18) have a different geometric shape.

5. Switch (10) according to one of the preceding claims, wherein - the moving contact (16), the first take-off contact (17) and the second take-off contact (18) each have abutment regions (23) with which they bear against the take-off contact (13) and the fixed contact (14) in the first position.

6. Switch (10) according to one of the preceding claims, wherein - the first arcing contact (17) and the second arcing contact (18) are arranged in the second position relative to the moving contact (16) in such a way that at least one contact region (23) of the first arcing contact (17) and / or of the second arcing contact (18) protrude relative to the contact regions of the moving contact (16).

7. Switch (10) according to one of the preceding claims, comprising - a contact carrier (20) comprising a first support plate (201) and a second support plate (202), which is arranged parallel to the first support plate (201), - at least one further moving contact (16), wherein - the moving contacts (16), the first burn-off contact (17) and the second burn-off contact (18) are attached to the support plates (201, 202) and are arranged between the support plates (201, 202).

8. Switch (10) according to the preceding claim, wherein - the moving contacts (16) and the first arcing contact (17) and the second arcing contact (18) are arranged in a stack-like manner in the contact carrier (20) and each have parallel, superimposed elongated holes (31); - the moving contacts (16), the first arcing contact (17) and the second arcing contact (18) are movably mounted between the support plates (201, 202) by means of guide pins (32) which pass through the elongated holes (31).

9. Switch (10) according to the preceding claim, wherein - the guide pins (32) with the elongated holes (31) form a mechanical stop for the moving contacts (16), the first arcing contact (17) and the second arcing contact (18) during the switching operation of the switch (10).

10. Switch (10) according to one of claims 7 or 8, wherein - the elongated holes (31) of the moving contacts (16), of the first arcing contact (17) and of the second arcing contact (18) are each formed differently in their length, such that the moving contacts (16), the first arcing contact (17) and the second arcing contact (18) reach the mechanical stop at different times during the switching operation of the switch (10).

11. Switch (10) according to one of the preceding claims, wherein - the moving contacts (16), the first take-off contact (17) and the second take-off contact (18) are arranged on the contact carrier (20) such that in the first position they are resiliently biased against the take-off contact (13) and the primary fixed contact (14).

12. Switch (10) according to one of the preceding claims, wherein - the moving contacts (16), the first arcing contact (17) and the second arcing contact (18) are arranged in a stack such that the moving contacts (16) are arranged between the first arcing contact (17) and the second arcing contact (18).

13. Switch (10) according to one of the preceding claims, comprising a secondary fixed contact (15) and a second contact unit (37), which is arranged symmetrically to the contact unit (12) with respect to an axis of symmetry (22), which runs through the pivot axis (21), and has a third arcing contact (38), which is designed identically to the first arcing contact (17), and a fourth arcing contact (39), which is designed identically to the second arcing contact (18), wherein - the fourth arcing contact (39) lies on a plane with the first arcing contact (17) and the third arcing contact (38) lies on a plane with the second arcing contact (18).

14. Switch (10) according to one of the preceding claims, which is designed as a permanent main switch (10) or as a disconnecting switch (10) for or in an on-load tap-changer (30) of an on-load tap-changer (40).

15. Diverter switch operation (30) for or in an on-load tap-changer (40) of a step transformer, comprising - a switch (10) according to any one of the preceding claims 1 to 14; - a first current path (61) comprising at least one moving contact (16) of the switch (10); - a second current path (62) comprising a first arcing contact (17, 38) of the switch (10); - a third current path (63) comprising a second arcing contact (18, 39) of the switch (10); - a fourth current path (64) comprising at least one vacuum interrupter (19) - a fifth current path (65) connecting the switch (10) to a take-off lead (60); characterized in that - the first current path (61) has a certain resistance (R1), - the second current path (62) has a resistance (R2) which is greater than the resistance (R1) of the first current path (61), - the third current path (63) has a resistance (R3) which is greater than the resistance (R2) of the second current path (62).

16. Diverter switch operation (30) according to the preceding claim, wherein - the resistances (R2, R3) of the second and third current paths (62, 63) can be determined by the material of the respective arcing contact (17, 18, 38, 39) and / or by the geometric shape of the respective arcing contact (17, 18, 38, 39).

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