RU1817152C - Overcurrent electromagnetic release for automatic circuit braker - Google Patents

Abstract

Usage: in circuit breakers x. SUMMARY OF THE INVENTION: a device consisting of an electromagnetic overcurrent release containing measles 1, rmo (I) 3c winding 5 and core C) 2, and a thermal release containing winding 6 and a thermoelectric transducer, is equipped with a magnetic shunt to simplify the design and increase speed (MSH) 4 connected by a magnetic drive with R 3, C 2 is made in the form of a permanent magnet, and the winding 6 is placed on MSH 4. 2 ill.

Description

The invention relates to electrical engineering, in particular to circuit breakers.

The aim of the invention is to simplify the design and increase the speed of the electromagnetic release.

On Fig, 1 presents an electromagnetic release, General view; in FIG. 2 is a circuit for switching off coils of an electromagnetic release.

The electromagnetic release (Fig. 1) includes core 1, core 2 of a permanent magnet, pmo 3, magnetic shunt. 4, the working coil 5 of the overcurrent release located on the frame, the working coil 6 of the thermal trip located on shunt 4, The working coils LKi and LK2 are connected in series to the contact of the circuit breaker, or. to the current sensor RS (Fig. 2), while the working coil LK2 of the thermal release is connected by key K to the current sensor RS. For example, a voltage divider consisting of a resistor and a thermistor RK is connected to the input of the key K (Fig. 2).

The circuit breaker operates as follows.

Under normal conditions in the circuit breaker circuits, core 1 (Fig. 1) remains attracted to the core under the influence of electromagnetic force from the magnetic flux induced by a permanent magnet. In this case, the working coil 6 (Fig. 1) of the thermal release remains open, since the key K (Fig. 2) is open.

At short-circuit currents in the circuit of the circuit breaker, the current in the working winding 5 (Fig. 1) of the overcurrent release is sharply weakened, since the magnetic fluxes induced by the coil 5 and the permanent magnet are directed in the opposite direction. And with sufficient attenuation of the resulting flow

measles 1 disappears. Coil 6 (Fig. Thermal release remains open).

At overload currents, the temperature of the conductor increases and, if it exceeds

permissible, which can be controlled, for example, with a thermistor RK (Fig. 2), a sufficient voltage is applied to the input of the key 4 to close the key K, which leads to the connection of the coil LK2 to the current sensor RS. AT

In this case, the magnetic flux from the coil 6 (Fig. 1) of the thermal release attenuates the magnetic flux from the permanent magnet 2, since it is opposite in direction, and the resulting magnetic flux is weakened so that

measles 1 disappears.

Simplification of the trip design is achieved by the multifunctionality of the unified trip design.

An increase in the speed of the overcurrent release is ensured by the fact that when it is activated, the electromagnetic force decreases much faster with an increase in the working gap between the core and the core than when the release is triggered when the core is attracted, when the electromagnetic force increases at a slower rate with a decrease in the working gap.

Claims (1)

SUMMARY OF THE INVENTION An electromagnetic current release of a circuit breaker comprising an electromagnetic overcurrent release circled by a current of a circuit to be protected, consisting of a winding and a thermoelectric converter included in the circuit of this winding, characterized in that, in order to simplify the design and increase the speed, it is equipped with a magnetic shunt connected by a magnetic circuit with a PM, the core is made in the form of a permanent magnet, and the coil of the thermal release is placed on the magnetic shunt.