SU515183A1 - Circuit breaker - Google Patents

Description

j The invention relates to automatic devices designed for the protection of low-voltage electric circuits of constant and mixed current, which ensure the opening of the working contacts in case of overloads and short circuits. A circuit breaker with electrothermal and electromagnetic opening of working contacts is known, in the construction of which a current-carrying bimetappic plate with an electromagnet attached to it is used. However, the use of a current-carrying bimetallic plate to protect against overload of an overload without additional restraining devices leads to the inevitable bounce of the contacts, which significantly reduces the life their services. The used electromagnets, which form an electrical contact between themselves and repel each other when: a short-circuit current passes through their windings; Whose closure also affects the fast contact life, since the device design is such that when a minimum gap occurs between the contacts disappears current in the circuit, and to maintain it, an electric arc is required, an overlap of the resulting gap, which must accompany the movement of the magnets until the switch is fully activated. In addition, when a certain amount of current is reached, when electromagnets begin to repel, they are forced to overcome the opposing force of the working springs, which significantly increases the response time. The aim of the invention is to increase reliability, durability and decrease response time. I For this electromagnet is located. in a magnetic field between two permanent magnets, the entrances together with it in the plane of the bend1 {and the thermo-bimetallic plate, and the winding of the electromagnet is wound so that the magnetic; field generated by the electromagnet, the .aenpesf foam of the opposite magnetic field of the permanent magnet .I

Such a warp position is placed on the electromagnet and constant light on the breaker, which is significantly smaller than the maximum short-circuit current of the short cap, since at the moment of repulsion of the electromagnet from the permanent magnet, the short-term short-circuit current, since at the moment of repulsion of the electromagnet from the permanent magnet of the short circuit, the current level of the background, the main body of the main body of the current level, the level of the current level, the level of the current level of the background, the level of the main body of the current level, would not have the same level of the body of the main body of the current level, the level of the background, the level of the main body of the current level would be used to)) should be used to) from each other, as well as to exclude their contacts in the off state during short-term short-circuit currents.

Ng (the drawing shows the construction of an automatic circuit breaker in the off state.

The circuit breaker contains a thermo-bimetallic plate 1, a thermostat, mounted on the housing 2. On the plate

1 coil 3 indirect heating is wound and one of the main rocking contacts 4 switches is installed. On the continuation of the plate 1, the core 5 of the electromagnet 6 is fixed. The winding of the electromagnet 6 is wound on the core 5 in such a way that the magnetic field created by the amperages of the windings of the electromagnet 6 is directed opposite to the magnetic field formed by the permanent magnets 7 and 8. On the case

2, by means of the adjusting screws 9, two permanent magnets 7 and 8 are fixed, which in static mode hold electromagnet 6 in the upper (main contacts 4 are closed) or in the lower position (main contacts 4 are open).

On housing 2, a contact spring 1O is fixed, at the end of which a second main contact 11 is installed. Screws 12 and 13 serve for adjusting the current setting.

A pusher 14 is fixed on the thermo-bimetallic plate 1, which acts on the contact spring 15 of the signal contact group and on the contact spring 16 of the signal contact group when the actuator automatically activates during manual switching using the handle 17.

The switch works as follows.

Ia initial position (main contacts 4 razom.guty using the handle 17 perevdesim switch to another position (main contacts 4 are closed). As soon as the main contacts 4 are closed, the heartbeat spring 1O, contact 11., contact 4 helix 3 indirect heating, the winding of the electromagnet 6 and the spring 16, will pass a current.

At rated current, the switch is in a steady state, since the flowing current is small.,

When flowing through the overload switch, the spiral 3 of indirect heating is heated and the thermo-bimetallic plate 1 is bent.

At the same time, a partial magnet 7 is weakened by an oppositely directed magnetic field created by the overload current in the electromagnet 6.

There will be forces that will tear off the electromagnet from the permanent magnet and open the contacts 4 and 11, as well as switch the springs 15 and 17 of the signal contact group.

When passing through a short-circuit current switch, which is many times greater than the rated current, in the winding of electromagnet 6 a counter magnetic field is created, much larger than the magnetic field produced by the passage of overload currents. In this case, ferrodynamic repulsive forces appear, which reject the electromagnet 6 from the permanent magnet 7 and simultaneously disconnect the contacts 4 and 11,

Claims (1)

Invention Formula Automatic switch with electric. thermal and electromagnetic opening, containing an electromagnet fixed to a thermo-bimetallic plate, distinguished by the fact that, in order to increase reliability, durability and decrease the response time, the electromagnet is located in a magnetic field between two permanent magnets installed along with it in the plane of bending thermo-bimetallic plate, and the electromagnet winding is wound so that the magnetic field created by the electromagnet is directed opposite to the magnetic field of the permanent magnet.