SU1337932A1 - Maximum-current tripping device - Google Patents

Abstract

The invention relates to electrical engineering, to the field of low-voltage apparatus. The aim of the invention is to increase the reliability of operation of the maximum current release. The maximum i current release (MRI) combines in one block the functions of overcurrent protection with time delay and currents of which are closed without time delay. The magnetizing conductor 1, in which the current of the protected circuit flows, contains a section in the form of a loop 2 of a material with a reversible shape memory, placed inside the magnetic circuit 3 with an opening 4, through which the rod 5 passes, made of a nonmagnetic material. The loop 2 also has an opening 6 through which the end of the rod 5 passes, facing the bark 7. Expansion 8 on the rod 5 serves as a support for the rod itself and its return spring 9. The bark is returned to its initial working position by the spring 10. The rod 5 when MRI is triggered acts on the rail 11 of the free-release mechanism. The lack of communication between the thermal deformations of loop 2, which moves the rod 5 as a result of its expansion when heated by an overload current, and the movement of the core 7 at a short circuit current increases the reliability of the MRI scan. 2 Il. (L 00 Yu e

Description

The invention relates to electrical engineering, to the field of low-voltage apparatus, namely to the maximum current release of circuit breakers,

The purpose of the invention is to increase the reliability of the operation of the maximum current tripping.

Figure 1 shows the maximum current release; figure 2 - the position of the magnetizing winding with unacceptable overload currents.

The magnetizing winding 1, in which the current of the protected circuit flows, contains a section in the form of a loop 2 from a material with a reversible shape memory, placed inside the magnetic circuit 3 with an opening 4, through which the rod 5 passes. The loop 2 also has an opening 6, through which the end passes rod 5 facing korya 7. Spreading 8 on rod 5 serves as a support for the rod itself and its return spring 9. The return of the core to its initial working position is carried out by the spring 10. The rod 5 acts on the rail 11 upon actuation of the release device free release release

Loop 2 of a material with a reversible shape memory is subjected to such preliminary thermomechanical processing that at the transition temperature it is distributed with a displacement of the middle portion towards the opening 4 in the magnetic conductor Z. When the rated current and currents are less than nominal, and also for acceptable overload currents flowing in the winding-conductor 1 and loop 2, the heating of the loop is insufficient to change its shape. The magnetization of the magnetic core 3 and the core 7 is also insufficient for the force of attraction of the core to overcome the elastic forces of the spring 10. With unacceptable overload currents of the loop 2, it is heated to a temperature of change in its shape, the middle of the loop is displaced into the opening 8 , moves the rod 5 all the way into the rail 11. The rail 11 rotates, triggers the free tripping mechanism, and the circuit breaker shuts off the circuit. The current in conductor 1 and loop 2 is terminated, loop 2 cools and takes on its original form

spring 9 returns the rod 5 to its original position.

At short-circuit currents, due to the short duration of the process, loop 2 does not have time to deform, however, the magnetization of the magnetic core 3 and the core 7 is sufficient for the force of attraction

The core has exceeded the elastic force of the spring 10. The armature begins to move, reaches the rod 5 and pushes it all the way into the rail 11, causing the free tripping mechanism to trip. The rod 5 at the same time passes through the hole 6 in the loop 2, without deforming it and not creating any additional load on it. The return of the core 7 to its original position occurs under the action of the spring 9.

Other variants of the proposed release are possible. In particular, the electromagnet measles can be rotatable, and the loop

from a material with a reversible shape memory —wave-bent to increase the displacement of the portion connected to the rod with sufficient hinge stiffness.

Thus, although an element from a material with a reversible shape memory is involved in magnetizing the trip electromagnet, its effect on the free trip mechanism is not related to the action of the core, which eliminates false alarms and, therefore, increases the safety of the release.

The proposed maximum current release can be applied in various designs of circuit breakers designed for protection against preload currents with time delay and short circuit currents without time delay.

Claims (1)

Invention Formula A maximum current release of a circuit breaker with a combined thermal and electromagnetic protection, comprising an electromagnet consisting of a magnetic core, a core and a magnetizing winding partially or completely filled from a material with a reversible shape memory, and an uncoupling mechanism, characterized in that reliability of operation, it is equipped with a spring-loaded rod of non-magnetic material; part of the magnetizing winding, made of a material with a reversible shape memory, is placed inside the unit is made in the form of a loop with a fixed base and is connected to a spring-loaded rod of non-magnetic material, the rod is installed with the ability to interact at one end with the release mechanism, and the other end with the electromagnet core, and in the magnetic core there is an opening through which the spring-loaded rod of non-magnetic material. Editor A. Ogar Compiled by S. Gordon Tehred V. Kadar Order 4135/49 Circulation 697 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., 4 (picture 2 Corrector S.Cherni