SU438060A1 - Safety switch - Google Patents

Description

one

The invention relates to the field of energy distribution and can be used in electric power plants of 6-10 kV in urban electrical networks, which use the simplest types of protection against damage to network transformers and power cables, as well as in partial or full automation schemes for distribution networks.

Known fuses-switches, containing a frame with supporting insulators, on which are installed fuses with contact caps and a fusible insert, a cutting mechanism and an actuator that ensures the rotation of the shaft of the cutting mechanism through 90 °.

However, the known fuses-switches poorly disconnect small currents.

In order to eliminate this drawback, each fuse of the proposed switch-breaker is provided with an insulating disk with holes around the circumference of the number of wires of the fusible insert installed in front of the cutting mechanism, which is made in the form of a shaft and tube made of insulating material with holes along a straight line according to the number of wires of the fusible link into which the metal bushings are pressed. The cutting mechanism is installed in one of the contact caps fuse. The mechanical connection of the shaft of the cutting mechanism with the drive is made in the form of a metal square sleeve mounted on the brace of the supporting insulator.

FIG. 1 shows a fuse-switch in the section; in fig. 2 - fuse switch with actuator.

The contact cap 1 of the fuse is a brass piece in which the textolite sleeve 2 is placed. In the contact cap 1 there is a socket and an opening for a cutting shaft 3 made of a textolite. Holes are drilled in the cutting shaft 3 and the sleeve 2, the number of which corresponds to the number of wires of the fusible insert

4. For a better cut of the fusible insert 4, steel bushings 5 are pressed into these holes, at the same time this design allows to avoid welding of the fusible insert 4 to the sleeve 5. Fusible wires

the inserts 4 are pulled through the matching holes of the shaft 3 and the sleeves 2, are passed through the holes in the cover 6 and sealed.

In a standard wire fuse, the fuse-links are soldered to the contact caps around the circumference. The holes of the cutting mechanism are located in one plane. In order to prevent the wire from fusible inserts, a textolite disk is installed when pulling them through the cutting mechanism.

7 with circumferential holes, the number of which corresponds to the number of wires of the fusible insert. Asbestos packing 8 and nut 9 serve to seal the cartridge 10, which ends with another contact cap 11.

A high-voltage fuse-switch (Fig. 2) is mounted on the supporting insulators 12 on the frame 13 in which the drive shaft 14 is mounted, turning under the action of the power springs 15. The transfer of movement from the drive shaft to the cutting shaft of the control mechanism is carried out through a system of levers 18, made of PCB.

The cutting shaft 3 does not perceive the bending forces from the levers 16-18, these forces are perceived by the bracket 19, in which the sleeve 20, having an annular groove, rotates. The end of the screw 21 enters the groove, preventing its axial movement. For a rigid connection with a system of levers 16-18, the sleeve 20 is made square. The articulation of the sleeve 20 and the cutting shaft 3 is carried out using a square hole.

The mechanism is held in the on position by the ratchet 22 and the latches 23 mounted on the bracket 24. The trip electromagnets are mounted to the drive mechanism 25.

The described device operates as follows.

When the relay protection trips, the shut-off electromagnet acts on the latch 23, releasing the ratchet 22 and the shaft 14 with it. The shaft rotates by transmitting motion to a system of levers 16-18 that rotate the sleeve 20, and through the latter the control shaft also turns. Moving relative to the fixed sleeve 2, the shaft 3 cuts the fusible insert. The arc that arises in this case is quenched inside the cartridge.

Subject invention

Claims (2)

1. A fuse-switch, containing a frame with supporting insulators, on which fuses are installed with contact caps and a fusible insert, cutting a mechanism and an actuator providing rotation of the shaft of the cutting mechanism by 90 °, characterized in that, in order to reduce the tripping time of small currents, each fuse is provided with an insulating disc with holes along the circumference according to the number of wires of a fusible insert, installed in front of the cutting mechanism, which is made in the form of a shaft and tube, made of an insulating material with openings arranged in a straight line along the number of wires of the fusible insert into which metal bushings are pressed This cutting mechanism is installed in one of the contact caps fuse. 2. Fuse-switch according to claim 1, characterized in that, in order to reduce bending forces on the fuses, the shaft of the cutting mechanism is connected to the drive with the help of a metal square sleeve, mounted on the support bracket bracket. sixteen P