FI66266B - FOLLOW-UP FOLLOWING FRAMEWORK - Google Patents

Description

1 66266

Arc damage prevention device for insulated overhead lines

The invention relates to an arc damage prevention device 5 for insulated overhead lines, which device comprises a body intended to be attached in galvanic contact with the conductor of the insulated conductor.

Open conductors coated with a thin layer of insulating material and overhead conductor lines formed therefrom and the reasons for their use are described in FI patents 53 373 and 53 526. Although such conductors with a thin layer of insulating material achieve several advantages, they also have some problems that do not occur with bare open conductor structures. One such is that the arcs generated between 15 e.g. climatic overvoltage phase conductors cannot move along the conductors but remain burned in place at their point of ignition, i.e. usually where the insulation is damaged or removed for some reason e.g. In this case, the conductor burns very quickly under the influence of the arc. To prevent this phenomenon, insulated overhead lines are fitted with arc damage prevention devices with a massive part to which the melting effect of the arc is directed. Insulated overhead lines 25 also have the disadvantage that in order to perform earthing, the conductor must be stripped from the earthing point, whereby in order to avoid the formation of several exposed points, the earthing is practically always connected to the same conductor point. This can easily damage the cable at this point.

According to the invention, the conductive damage to the conductor of repeated earthing is prevented by means of the arc damage prevention device according to the invention, so that a protrusion is attached to its body for fixing the earthing.

35 In this case, the earthing can always be carried out safely and without damaging the cable to the eg loop-shaped projection of the arc damage prevention device.

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In the following, the structure of the arc damage prevention device according to the invention will be described in more detail with reference to the accompanying drawing, in which Fig. 1 shows a side arc protection device according to the invention, Fig. 2 shows a section of the device Fig. 4 shows a section of the device of Fig. 3 along the line BB of Fig. 3.

Figure 1 shows an arc damage prevention device according to the invention comprising a body 1 and a loop-like projection 5 formed integrally therewith. As can be seen in Figure 2, the body 1 is formed of two parts 1a and 1b connected to each other by bolts 6 and 7. , that the halves are pressed against the conductor 2 placed in the trough formed between them. The insulated conductor 2, comprising e.g. an alloy aluminum conductor 3 and a thin insulating layer 4 facing 20, is stripped exposed against the body 1 to form a galvanic contact between the conductor 3 and the body 1. In addition, depressions are formed in the body 1 at the insertion points of the conductor 2 to ensure that the insulator-free portion of the conductor 2 does not extend beyond the body 1, thereby creating a risk of arcing, e.g., between the adjacent conductor and the bare portion. In addition, the edge portions of the body 1 have massive bulges to which the melting effect of the arc is applied.

The clamping bolts 6 and 7 of the arc damage prevention device according to Figures 1 and 2 are located above the conductor, so that it can be mounted on the conductor simply by loosening the bolts slightly, allowing the conductor 2 to pass between the body parts 1a and 1b without having to completely remove the body parts 35. one another. In this way, the arc damage prevention device according to Figs. 1 and 2 remains suspended on the conductor 2 even before the bolts 6 and 7 are tightened.

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Figures 3 and 4 illustrate another embodiment of an arc damage prevention device according to the invention. In the embodiment of Figures 3 and 4, the body 10 of the device is formed in the shape of an open trough from above. This chute is then mounted 5 on the peeled part of the conductor 12 by first placing the conductor 13 in the chute, after which a rounded compression part 18 preferably rounded according to the conductor is placed on the conductor and then U-shaped threaded bolts 16 and 17 are inserted. 19 ... 22 (nut 22 not shown). Before inserting the nuts 19 and 20, the still free bolt ends are passed through the holes formed in the flattened ends of the arcuate bracket 15, after which the nuts 19 and 20 are inserted to tighten the bracket 15 15 on the frame 10. The bracket 15 thus acts as a grounding -nitysosana.

The idea according to the invention of connecting the site earthing attachment point to the arc damage prevention devices 20 can also be widely applied in connection with arc protection devices other than, for example, o, without departing from the spirit of the present invention and the scope of the appended claims.