SU920877A1 - Switch for high rated currents - Google Patents

Description

(54) SWITCH ON BIG BUT / LINAL1

TOKI

one

The invention relates to switches for high rated currents, preferably high voltage ones.

Known switches have main and arc suppressing current-carrying circuits containing respectively fixed and movable main and arcing contacts. In such switches, both current-carrying circuits are closed in the on position of the switches, and the ratio between the resistances of the main IQ and arcing circuits is such that the arcing circuit branches off a smaller part of the total current, and the main part of the current passes through the main circuit, which has a more massive contact system 1.15

The disadvantage of these switches is that the heating temperature of the contacts of the arcing circuit in the nominal mode is determined by the heat sink due to the thermal conductivity from the warmer main circuit and the heating from the current passing through the arcing circuit itself. The influence of these two factors limits the value of the rated current of the switches to more currents according to the condition of the permissible temperature of the contact parts in the arcing circuit.

Closest to the proposed technical entity is a switch for high rated currents, comprising a main circuit and an arcing circuit, having a fixed lamella sliding contact, a movable cylindrical contact, and a fixed lamella break contact. The movable cylindrical arcing contact has, in the zone of contact with the fixed lamella break contact or in the zone of contact with the fixed lamella slide contact, an insulating insert.

. Another embodiment of the same switch is option- when the length of the movable arcing contact is chosen so that in the on position of the switch the end of the movable contact completely extends from the fixed lamella sliding contact and the contact from the sliding turns into opening.

In both versions, in the on position, the switch interrupts the current path in the arcing circuit, and therefore all current flows only along the main circuit. This allows the rated current in the main circuit to be increased independently of the arcing circuit 2. However, both of these options have disadvantages. The disadvantage of the first switch is that the insulating insert melts under the action of a high arc temperature, which leads to the formation and destruction of the insulating ring, the formation of great friction as a result of the contact of the contact working surfaces of the lamellae with the worn ring and the deterioration of these surfaces. The disadvantage of the second switch is that when switching the switch in the arcing circuit, instead of one lamellar breaking contact, two fixed lamella contacts (opening and sliding) are burned under the arc, which greatly reduces the arc resistance of the arc-suppressing circuit as a whole. The purpose of the invention is to increase the arc resistance of the contacts of the arcing circuit and the possibility of unification of the arc circuit for a series of switches for different rated currents. The goal is achieved by the fact that in a switch for high rated currents, in particular in a high-voltage circuit containing a main conductor, a circuit and an arcing circuit, includes a fixed lamella break contact, a movable cylindrical contact and a fixed lamella slide contact and having in the on position the breaker of the current path between the fixed lamella break contact and the movable cylindrical contact, the indicated break of the current path is provided by the K0v opening, the dimensions of which The second is selected from the condition of providing a gap between the surfaces of the lamellae and the moving arcing contact in the on position of the switch. To increase reliability, the switch is provided with an insulating guide for a cylindrical moving contact mounted on the body of the lamella break contact. FIG. 1 shows an example of making a switch with a movable arcing contact with an annular recess located in the area of the contacting surfaces of the lamellae of the fixed lamella interrupting arcing contact; in FIG. 2 shows an example of a switch with a guide on a stationary lamellar interrupting arcing contact (only a section of a part of the fixed lamella interrupting arcing contact is shown, the rest is similar to the image in Fig. 1). The switch (see Fig. 1) contains current leads 1 and 2, to which two circuits (main and arcing) are connected in parallel. The main circuit has an unavailable sliding 3, a movable 4 and a fixed disconnecting 5 contacts, an arcing contour — a fixed lamella sliding 6, a movable 7, and a fixed lamella disconnecting 8 contacts. The moving arcing contact 7 in the zone of the contacting surfaces of the lamellae .9 has an annular recess 10. The switch shown in FIG. 2 differs from the previous one shown in FIG. 1, in that the insulating guide 11 for the movable arcing contact 7 is located on the case of the stationary lamel breakable arcing contact 8. The principle of operation of the switch shown in FIG. 1, in the on position of the switch, the movable arcing contact 7 occupies a position when the recess 10 is located in the zone of the contacting surfaces of the lamellae 9, which ensures the presence of a gap between the movable 7 and the fixed 8 arcing contacts and the gap of the current path in the arcing loop . The main circuit is then closed and the full current of the circuit breaker flows through it. When disconnected, the tip of the movable arcing contact 7 comes into contact with the contacting surfaces of the lamellae 9, after which the main contacts 4 and 5 are opened and the entire current passes through the arcing circuit. After the arcing contacts 7 and 8 are opened, the arc is finally extinguished. When the switch is turned on, the current load or short-circuit current first closes the extinguishing contacts 7 and 8, then the main contacts 4 and 5, after which the tip of the moving arcing contact 7 opens with the lamellae 9 and the current from the extinguishing circuit is reset to the main circuit, full current switch It passes through the main contacts only. When contact 7 is opened with lamellae 9, when the current is ejected from the arcing circuit, an arc arises, which quickly goes out. The operation of the switch shown in FIG. 2 is similar to the operation of the switch shown in FIG. 1. The AND direction improves the direction of movement of the moving arcing contact 7 and provides a guaranteed gap between the fixed lamella break contact and the moving arcing contact in the on position of the switch, which increases the reliability of operation.

Claims (2)

1. A switch for large nominal currents, in particular a high-voltage, containing the main current-carrying circuit and the arcing circuit, includes a fixed lamella break contact, a movable cylindrical contact and a fixed lamella sliding contact and a break in the current path between the fixed one lamella break contact and a movable cylindrical contact, characterized in that, in order to increase the arc resistance of the arcing contacts and the possibility of uni ation arc circuit breakers for series An annular recess is made for various nominal currents in the arcing movable cylindrical contact in the area of the contacting surfaces of the blades of the fixed lamella disconnecting contact, the dimensions of which are chosen from the condition of providing a gap between the surfaces of the blades and the moving arcing contact in the on position of the switch. 2. A switch according to claim 1, characterized in that, in order to increase reliability. The lamella break contact is provided with a housing with an insulating guide for a moving arcing contact. Information sources, taken into account in the examination 1. USSR author's certificate number 187867, cl. H 01 H 33/92, 1966. 2. The patent of France No. 1.445.422, cl. H 01 H, 1965.