DE202014100550U1 - Device for grounding and / or short-circuiting - Google Patents

Abstract

Device for grounding and / or short-circuiting lines and / or electrical switchgear with: at least one electrically conductive rope (1) with at least two electrically conductive connecting elements (2A, 2B) at the end; at least two contact devices (3A, 3B), which are each connected to the connecting elements (2A, 2B) and enable contacting of the lines and / or electrical switchgear; and an external insulation (4A, 4B) for at least partially isolating the at least one rope (1) and / or the connecting elements (2A, 2B), characterized in that the at least one electrically conductive rope (1) comprises aluminum and a tensile strength greater than 200 MPa.

Description

The present invention relates to a device for grounding and / or short-circuiting of lines and / or electrical switchgear and in particular to a device for grounding and / or short-circuiting high-voltage cables and low-voltage switchgear.

Such devices are required to exclude a risk to personnel during repair work. For example, when working on electrical cables and / or switchgear this off before work or enabled, then tested for voltage and finally grounded or shorted.

For grounding and / or short-circuiting usually used devices with copper cables, the ends of cable shoe pockets are made to which terminals made of copper or brass are attached. Phase terminals are connected to respective phase conductors, while a ground terminal is connected to ground.

Since there are often large distances between the earthing point and the lines or switchgear to be ground of several meters, the high weight, in particular the copper cables commonly used is disadvantageous in the handling of conventional earthing and short-circuiting devices.

On the other hand, however, there is a need for high-conductivity grounding and short-circuiting devices, since minimum short-circuit resistance typically requires a current flow of 4.5 kA to 42 kA for 0.5 seconds.

Furthermore, it is of importance for the manageability, in particular of mobile or portable earthing and short-circuiting devices, that they not only have a low weight but, moreover, have high flexibility and high durability.

The invention is therefore based on the object to provide a device for grounding and / or short-circuiting of lines and / or electrical switchgear, which has improved handling while increased durability.

According to the invention, this object is solved by the features of claim 1.

Preferably, the device for earthing and / or short-circuiting lines and / or electrical switchgear at least one electrically conductive cable with at least two end-side electrically conductive connecting elements, at least two contact devices, which are respectively connected to the connecting elements and a contacting of the lines and / or electrical Switchgear allow, and an external insulation for at least partially insulating the at least one cable and / or the connecting elements, wherein the at least one electrically conductive cable comprises aluminum and has a tensile strength greater than 200 MPa. Contrary to the prejudice of the art, according to the invention therefore ropes or materials for earthing and / or short-circuiting devices are used for the first time, which are not manufactured or defined for electrical applications. Nevertheless, surprisingly, in particular when using the above materials, excellent handleability and fatigue resistance of the earthing and short-circuiting device according to the invention are evident.

Preferably, the electroconductive Al rope has a tensile strength of from 230 MPa to 260 MPa, and more preferably from 240 MPa to 255 MPa, thereby further improving handleability due to increased flexibility and further realizing sufficient durability.

In particular, the electrically conductive cable may comprise an aluminum alloy comprising at least one alloying element from the group of Si, Mn and Mg or a combination thereof, wherein a mass fraction is greater than 1%. In such an alloy for the Al rope, durability and handleability are further improved.

For example, the content by weight of Mg may be greater than 0.35%, preferably in the range of 0.36% to 1.2%, more preferably in the range of 0.6% to 1.2%. Further, the mass ratio of Si may be in a range of 0.2% to 1.3%, and more preferably in a range of 0.7% to 1.3%. The mass fraction of Mn may be in a range of 0.4% to 1.0%, for example, thereby providing optimum durability and handleability for the rope and thus for the earthing and short-circuiting device.

Preferably, the electrically conductive cable 150 to 2000 wires work hardened, whereby with sufficient durability and low weight increased flexibility of the rope is realized.

In the further subclaims further advantageous embodiments of the invention are characterized.

The invention will be described below with reference to embodiments with reference to the drawings.

Show it:

1 a simplified representation of a grounding and Kurzschließseils for use in a grounding and short-circuiting device according to a first embodiment;

2 a simplified representation of a grounding and short-circuiting device according to a second embodiment;

3 a simplified representation of a grounding and short-circuiting device according to a third embodiment; and

4 a simplified illustration of a grounding and Kurzschließseils for use in a grounding and short-circuiting device according to a fourth embodiment.

In the following description of the figures, the same reference numerals are used for identical and identically acting parts.

1 shows a simplified representation of a grounding and Kurzschließseils 1 as it can be used in a grounding and short-circuiting device according to the present invention. The electrically conductive rope 1 may for example have a round or oval cross-section and consist of a plurality of wires. For example, the rope 1 consist of 150 to 2000 individual wires, which are intertwined or only parallel to each other. In this way one obtains a sufficiently high flexibility for the rope 1 ,

Preferably, the individual wires of the rope 1 work hardened and fully hardened, giving the mechanical strength of the rope 1 increased against impact and / or tensile stress. It was found that "solution annealed" and "cold paged" wires have insufficient material properties for the rope 1 realize and therefore be ruled out.

The material of the rope 1 or the individual wires, not shown, may preferably comprise aluminum. For example, the material of the rope 1 or the individual wires comprise an aluminum alloy whose main constituent is Al and which further comprises alloy constituents from the group of elements Si, Mn and Mg or a combination thereof. For example, the mass fraction of the other alloy constituents from this group is greater than 1%.

Preferably, as material for the rope 1 or for the individual wires used an aluminum alloy, which has a mass fraction of at least 0.35% Mg. Particularly suitable material properties for the rope 1 or for the individual wires result for a mass fraction of Mg in the range of 0.36% to 1.2% and in particular in a range of 0.6% to 1.2%.

Further, the above-described aluminum alloy for the rope 1 or for the individual wires have an additional mass fraction of Si in the range of 0.2% to 1.3% and in particular in a range of 0.7% to 1.3%, thereby further improving the material properties, in particular with regard to durability and handling to improve.

In addition, the aluminum alloy described above for the rope 1 or for the individual wires have an additional mass fraction of Mn in a range of 0.4% to 1.0%, which can further improve the material properties.

Preferably, therefore, the material for the rope 1 or for the individual wires of an Al alloy with 0.7-1.3% Si, 0.4-1.0% Mn, 0.6-1.2% Mg, max. 0.5% Fe, max. 0.1% Cu, max. 0.25% Cr, max. 0.2% Zn and max. 0.1% Ti, with the remaining mass fraction of the alloy having Al.

A particularly suitable material for the earthing and short-circuiting device consists in particular of an Al alloy with approx. 0.82% Si, 0.4-1.0% Mn, approx. 0.7% Mg, approx. 0.3% Fe, about 0.024% Cu, about 0.005% Zn and about 0.015% Ti, the remaining mass fraction of the alloy is about 98% Al.

According to the invention, the electrically conductive cable 1 may comprise pure aluminum and in particular an aluminum alloy, wherein a tensile strength of the cable 1 greater than 200 MPa (200 N / mm ² ). Although such ropes with a tensile strength greater than 200 MPa (200 N / mm ² ) are not regularly used or offered for electrical applications, it has surprisingly been found that such high-strength ropes are particularly suitable for the grounding and short-circuiting devices according to the invention, as they on the one hand good to handle and on the other hand have an extremely high durability.

In particular, Al-ropes having a tensile strength in a range of 230 MPa to 260 MPa and especially in a range of 240 MPa to 255 MPa have been found to be particularly suitable.

The suitability of the cables for earthing and short-circuiting devices is determined, for example, by their temperature behavior, since the devices are often stored unprotected against weather influences in the open air (eg next to railway lines). The ropes must therefore be equally handled in a wide temperature range (eg -30 ° C to + 30 ° C). Further, under such extreme conditions, the electrical properties of the cables should remain substantially unchanged over a long period of time in order to maintain the short-circuit capabilities even after prolonged storage under adverse environmental conditions.

According to 1 are at the ends of the rope 1 each electrically conductive connection elements 2A and 2 B intended. For example, be over the ends of the rope 1 pushed tubular connecting elements and then mechanically pressed with the rope ends, creating an electrical and mechanical connection with the individual wires of the rope 1 made in conjunction with the increased tensile strength sufficient durability of the rope especially at the transition connecting element / rope allows. For example, the remaining part of the tubular connector may be fully (ie flat) compressed and with an opening 5A . 5B , such as B. a hole provided. Alternatively, ready-made cable lugs with corresponding openings as connecting elements 2A and 2 B be connected to the rope ends.

For example, the connecting elements 2A and 2 B made of an aluminum material and in particular of the same material as the rope 1 , Preferably, the connecting elements 2A and 2 B be coated with Sn or Zn. The coating can be carried out, for example, galvanically.

Finally, the rope 1 with its at least two end-side electrically conductive connecting elements 2A and 2 B with an external insulation 4 be provided. Preferably, the rope can 1 completely and the fasteners 2A and 2 B coated with silicone or PVC insulation at least until the rope is pressed, thereby providing mechanical protection against impacts or shocks as well as electrical insulation. The outer insulation 4 is preferably chosen so that the requirements of the respective environmental and temperature conditions are met. Again, even when selecting the material for the outer insulation 4 to ensure sufficient flexibility and durability.

2 shows a simplified representation of a grounding and short-circuiting device according to a second embodiment, wherein like reference numerals designate like or corresponding components, which is why a repeated description is omitted below.

According to 2 can on the connecting element 2A now a ground terminal 3A and on the connecting element 2 B a phase connection terminal 3B be connected as contact devices. For example, the ground terminal 3A and the phase connection terminal 3B about fasteners 6 , such as As screws and nuts, which through the openings 5A . 5B the connecting elements 2A . 2 B are guided, fastened.

For example, the ground terminal 3A an electrically insulated hand spindle 7 have, with a ground potential-conducting member (not shown) can be contacted. On the other hand, the phase connection terminal 3B a contact hook 8th and a bayonet spindle 9 have, on which a (not shown) insulating rod can be plugged. By means of the insulating rod can now with the contact hook 8th connected electrically conductive rope 1 lifted to a line (not shown), hooked and then screwed to it.

Preferably, the contact devices 3A and 3B at least partially made of the above-described aluminum material, whereby the total weight of the earthing and short-circuiting device is further reduced and ease of handling is facilitated.

3 shows a simplified illustration of a grounding and short-circuiting device according to a third embodiment, wherein like reference numerals designate like or corresponding components, which is why a repeated description is omitted below.

According to 3 can on the connecting element 2 B For example, a so-called shatterproof contact hook 3C be used as a contact device for the line. The jam-proof contact hook 3C is in this case formed such that in the case of a short circuit, a drop of the line is impossible. Furthermore, the contact hook 3C a bayonet mount 10 have, on which in turn a (not shown) insulating rod can be plugged. By means of the insulating rod can turn that with the contact hook 3C connected electrically conductive rope 1 to a line (not shown) to be lifted and hooked.

For example, the jam-proof contact hook 3C at least partially made of the above-described aluminum material, whereby the total weight of the earthing and short-circuiting device is further reduced and ease of handling is facilitated.

4 shows a simplified representation of a grounding and Kurzschließseils for use in a grounding and short-circuiting device according to a fourth embodiment, wherein like reference numerals designate like or corresponding components, which is why a repeated description is omitted below.

For example, according to 4 a rope for each phase of the current 1B . 1C and 1D with end-mounted fasteners 2 B . 2C and 2D be provided, which has a branch piece 11 with a ground wire 1A with associated connecting element 2A are connected. As in 2 and 3 can be shown on the connecting elements 2A to 2D In turn, the ground terminals and / or phase terminals described above may be attached as contact means.

With a grounding and short-circuiting device of this type, multiphase lines or switchgear installations can be reliably short-circuited or earthed in a particularly simple manner.

The invention has been described above with reference to preferred embodiments. However, it is not limited thereto and in particular also includes combinations of the exemplary embodiments described above.

As the material of the contact devices and the connecting elements in particular aluminum or Al alloys has been described. However, the invention is not limited thereto and likewise includes contact devices and connecting elements of other electrically conductive materials. The fastener 6 is described by way of example as a screw with nut. In the same way, the fastener 6 However, also be realized by alternative fasteners and in particular by plug-in closures, adhesive bonds or riveted joints. The present invention has been described above with reference to single-phase and three-phase live leads. However, it is not limited to this and includes a different number of phases.

LIST OF REFERENCE NUMBERS

1

rope

2

connecting element

3

contactor

4

external insulation

5

opening

6

fastener

7

Handspindel

8th

Contact hook

9

bayonet screw

10

bayonet mount

11

junction box

Claims (14)

Device for earthing and / or short-circuiting lines and / or electrical switchgear with: at least one electrically conductive cable ( 1 ) with at least two end-side electrically conductive connecting elements ( 2A . 2 B ); at least two contact devices ( 3A . 3B ), each with the connecting elements ( 2A . 2 B ) are connected and allow a contacting of the lines and / or electrical switchgear; and an external insulation ( 4A . 4B ) for at least partially isolating the at least one cable ( 1 ) and / or the connecting elements ( 2A . 2 B ), characterized in that the at least one electrically conductive cable ( 1 ) Aluminum and has a tensile strength greater than 200 MPa. Apparatus according to claim 1, characterized in that the at least one electrically conductive cable ( 1 ) has a tensile strength of from 230 MPa to 260 MPa and in particular from 240 MPa to 255 MPa. Apparatus according to claim 1 or 2, characterized in that the at least one electrically conductive cable ( 1 ) comprises an aluminum alloy having at least one alloying element selected from the group consisting of Si, Mn and Mg or a combination thereof, wherein a mass fraction is greater than 1%. Apparatus according to claim 3, characterized in that the mass fraction of Mg is greater than 0.35%. Apparatus according to claim 3 or 4, characterized in that the mass fraction of Mg is in a range of 0.36% to 1.2% and in particular in a range of 0.6% to 1.2%. Device according to one of claims 3 to 5, characterized in that the mass fraction of Si in a range of 0.2% to 1.3% and in particular in a range of 0.7% to 1.3%. Device according to one of claims 3 to 6, characterized in that the mass fraction of Mn is in a range of 0.4% to 1.0%. Device according to one of claims 1 to 7, characterized in that the Connecting elements ( 2A . 2 B ) Have aluminum and are coated in particular with Sn or Zn. Device according to one of claims 1 to 8, characterized in that the at least one electrically conductive cable ( 1 ) has a plurality of work-hardened wires. Apparatus according to claim 9, characterized in that the plurality of work-hardened wires is in a range of 150 to 2,000. Device according to one of claims 1 to 10, characterized in that the outer insulation ( 4A . 4B ) Silicone or PVC. Device according to one of claims 1 to 11, characterized in that the contact devices ( 3A . 3B ) comprise as material aluminum. Device according to one of claims 1 to 12, characterized in that the contact devices ( 3A . 3B ) Have phase terminals and / or ground terminals. Use of the device according to one of claims 1 to 13 for earthing and / or short-circuiting lines and / or electrical switchgear.

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