RU142156U1 - AUTOMATIC CIRCUIT BREAKER CURRENT BREAKER - Google Patents

Abstract

1. The overcurrent release of the circuit breaker, containing a conductive busbar of rectangular cross section with two working parallel faces having a surface area much larger than the area of the side faces, a flat armature made of magnetic material, rotatably mounted, a return spring disconnecting the lever, characterized in that a hole is made in the central part of the armature through which a conductive busbar is passed, and the armature is fixed symmetrically using an axis parallel to the working faces of of the surrounding bus, an adapter block is also introduced, mounted on a common axis with the anchor and with the possibility of transmitting the influence of the anchor to the disconnecting lever. 2. The release according to claim 1, characterized in that the hole in the central part of the armature is made rectangular. 3. The release according to claim 1, characterized in that the conductive busbar and the armature are made in the middle (central) part with a step-shaped bend.

Description

The utility model relates to the field of electrical engineering and can be used in circuit breakers for high currents, designed to disconnect overload currents and short circuits, as well as operational switching on and off of electrical circuits in power supply facilities.

To disable the maximum short-circuit currents in circuit breakers, double-acting electromagnetic trip units are widely used, which simultaneously perform the functions of protection against overload currents and short-circuit currents [Kuznetsov P.C. Devices for the distribution of electrical energy for voltages up to 1000 V. Ed. 3rd, overwork, and add. - M .: "Energy", 1970].

A significant drawback of such releases is the limited ability to implement a wide variety of protective characteristics required to protect a wide range of modern electricity consumers.

Moeller circuit breakers of the NZM 2 type are known from Moeller [Product catalog 2011, NZM circuit breakers], which use an electronic release that provides protection against overload currents with a wide variety of adjustable characteristics, and an electromagnetic release to protect against large short-circuit currents that exceed nominal currents over 25 times. By the technical nature of such an electromagnetic overcurrent release is the closest to the claimed utility model and adopted as a prototype.

Known release of the maximum current of the switch NZM 2 (Fig. 1) contains a conductive busbar of rectangular cross section 1, a flat armature of magnetic material 2, a return spring 3 and a disconnecting lever 4, which perform the main function of the release. In addition, the node of the release includes a bus for attaching the mounting wires 5, a conductive rod 6 and a winding 7, designed to issue a signal to an electronic release. Bus 1 has a rectangular cross section, the two sides of which are substantially larger than the other two.

The bus 1 and the armature 2 are an electromagnet with an open magnetic system, in which there is no magnetic circuit. Under the action of a magnetic flux created by a short-circuit current 1KZ in bus 1 and closing through armature 2, armature 2 moves to the region of the maximum magnetic field gradient, i.e. the anchor 2 is attracted to the surface of the tire 1. At the same time, it acts on the disconnecting lever 4 with its movable end, which in turn drives the free trip mechanism, and the circuit breaker is instantly turned off. The return of the armature 2 to its original state after disconnecting the short circuit current occurs under the action of the return spring 3.

The disadvantage of the prototype is its low resistance to mechanical stress, because the anchor suspension system in it is a classic version of an unbalanced system. At certain values of the accelerations of vibration or shock with the direction of impact, for example, coinciding with the direction of movement of the armature (see Fig. 1), armature 2 begins to move under the action of inertial forces of the mass (in the absence of current I _short circuit), and the circuit breaker fails to trip. As a rule, for such suspension systems, the acceleration values of stable operation do not exceed several units g.

The aim of the proposed technical solution is to increase the resistance to mechanical stress of the overcurrent release circuit breaker, designed to disconnect the maximum short circuit currents.

This goal is achieved due to the fact that in the overcurrent release of the circuit breaker containing a conductive busbar of rectangular cross section with two working parallel faces having a surface area much larger than the area of the side faces, a flat armature made of magnetic material placed on the conductive busbar with the possibility of rotation, the return spring and a disconnecting lever, a rectangular hole is made in the central part of the armature through which a conductive busbar is passed, and the armature fixed symmetrically with an axis parallel to the working faces of the bus bar also introduced a transition block mounted on a common axis with the armature and to provide a transmission effect on the armature tripping lever. The conductive busbar and the armature are made in the middle (central) part with a step-shaped bend.

The technical result of the proposed design is the balancing of the movable armature mounted on the conductive bus, which significantly increases the stability of the structure to the effects of vibration and shock.

The technical nature of the proposed technical solution is illustrated by the drawings shown in FIG. 2, 3 and 4, where the following notation is accepted:

1 - conductive bus;

2 - a flat anchor made of magnetic material;

3 - spring return;

4 - disconnecting lever;

5 - bus for attaching mounting wires;

6 - conductive rod;

7 - winding;

8 - axis;

9 - adapter block;

B - a rectangular hole in the central part of the anchor 2.

The proposed overcurrent release of the circuit breaker contains a conductive busbar 1 of rectangular cross section with two working faces having a surface area much larger than the surface area of the side faces, a flat armature made of magnetic material 2, a return spring 3, a disconnecting lever 4, a bus for attaching mounting wires 5, a rod conductive 6, winding 7, axis 8 and adapter block 9.

The design elements of the release, realizing its main function of protection against currents I _kz , are bus 1, anchor 2, spring 3 and lever 4.

At least a rectangular hole B is made in the middle (central) part of the armature 2, through which a conductive bus 1 is passed. Anchor 2 is mounted symmetrically on the axis 8, which passes through round holes made in the armature 2 and the conductive bus 1. Moreover, the geometric axes of these the holes of the armature 2 coincide (are aligned) with the axis of symmetry of the armature, perpendicular to its side faces, and the geometric axis of the conductive bus 1 is parallel to its working faces (perpendicular to the side faces). Thus, the connection of the tire 1 and the armature 2 is a system similar to the “scissors” system. To ensure the fit of the working surfaces of the tire 1 and the armature 2 in the drawn (worked) state of the armature 2, the tire 1 and the armature 2 (or at least one of them) are made in the middle (central) part with a curved step shape. In order to achieve reliable transmission of force from the armature 2 to the disconnecting lever 4, a transition block 9 is introduced, which is installed on the same axis 8.

The release operates as follows.

When large short-circuit currents (overcurrents) appear in the conductive bus 1, the magnetic flux (magnetic field) sharply increases around this bus 1. Since any ferromagnetic body placed in a magnetic field tends to move in the direction of the maximum magnetic field gradient, and the field gradient is maximum near the surface of the conductive bus, the armature 2 is attracted by both ends to the bus 1, turning around axis 8. At the same time, it acts through the adapter block 9 on the disconnecting lever 4, which in turn removes the latch of the free trip mechanism (MCP) of the circuit breaker and is tripped.

Due to the hole in the anchor, it seems possible to connect two flat parts (rail and anchor) into a system similar to the “scissors” system, and their installation on a common axis provides reliable axisymmetric fixation relative to each other. In this case, balancing of the moving armature with high accuracy can be achieved, which is necessary and sufficient to achieve high stability of the system (structure) to the influence of mechanical factors (vibration and shock).

The proposed design of the overcurrent release is used in the working design documentation for circuit breakers for rated currents of 160 and 250 A, designed for operation in harsh conditions.

Claims (3)

1. The overcurrent release of the circuit breaker, containing a conductive busbar of rectangular cross section with two working parallel faces having a surface area much larger than the area of the side faces, a flat armature made of magnetic material, rotatably mounted, a return spring disconnecting the lever, characterized in that a hole is made in the central part of the armature through which a conductive busbar is passed, and the armature is fixed symmetrically using an axis parallel to the working faces of of the surrounding bus, an adapter block is also introduced, mounted on a common axis with the anchor and with the possibility of transmitting the effect of the anchor to the disconnecting lever. 2. The release according to claim 1, characterized in that the hole in the Central part of the anchor is made rectangular. 3. The release according to claim 1, characterized in that the conductive busbar and the armature are made in the middle (central) part with a step-shaped bend.

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