SU978228A1 - Maximum current disconnector - Google Patents

Description

(54) MAXIMUM CURRENT RELIEF

one

The invention relates to electrical engineering, more specifically to a low-voltage apparatus structure, and in particular, to automatic switches.

Protection devices are known in which a low-melting substance is used, when melted which, under the action of an elastic element, a part is moved, opening the contacts. Returning the device to its original working position requires reassembling the device or reheating before melting the fusible substance E1, 12.

The closest in technical essence to the present invention is a maximum circuit breaker current release, containing an elastic core, intended to act on a contact system, and a thermal element connected with it, made in the form of a syphon, within which a low-melting substance 3 is located.

This maximum current release provides only protection against overload currents and does not provide protection against short circuit currents. This disadvantage limits the capabilities of the device.

The purpose of the invention is the dissolution of functional capabilities.

This goal is achieved by the fact that the maximum current release of the circuit breaker is equipped with an electromagnet, d powered by the protected circuit, the resilient plate is made of ferromagnetic material or with a ferromagnetic overlay, and the electromagnet is installed with the possibility of acting on the specified plate.

The drawing shows the maximum current release.

Claims (3)

The elastic ferromagnetic plate 1, fixed on the bellows 2 with a low-melting 20 substance, by means of an adjusting screw 3, holds the pawl 4 of the free-release mechanism levers. Plate 1 serves as the crust of an electromagnet 5, the winding 6 of which is included in the circuit to be protected. Maximum current release works as follows. With unacceptable overload currents, the accumulative substance in the bellows 2 melts and the elastic plate 1 under the action of the pawl 4 rotates, freeing the pawl 4 from engaging with the screw 3, the free tripping mechanism is activated, opening the circuit breaker contacts. With the overload currents, the force developed by the electromagnet is not enough to empty plate 1. After the hardening of the low-melting substance in element 2, the pawl 4 can be brought into engagement with the screw 3 due to the elastic properties of the plate and closure of the lower part of the pawl 4. At current electromagite 5 short circuit develops a force sufficient to bend plate I and bring I dog 4 out. meshing with the screw 3. This process occurs without a time delay. The fusible substance does not succeed in melting.,. The electromacgr does not necessarily have to act directly on the elastic plate, as shown in FIG. 1. It can also attract another ferromagnetic part of the maximum release, rigidly connected with the elastic plate. 84 The proposed maximum current release can be used in circuit breakers of various designs that provide protection against overload currents with time delay and short circuit currents without a time delay. Claim 1: A maximum breaker current release, containing an elastic plate intended to act on a contact system, to a thermal element associated with it, designed as a bellows, within which a low-melting substance is located, characterized in that it is equipped with an electromagnet, powered by the current of the protected circuit, the elastic plate is made of a ferromagnetic material or with a ferromagnetic overlay, and the electromagnet is installed with impact on the specified elastic plate. Sources of information taken into account in the examination 1.Patent of France N 2010851, cl. H 01 H 37/00, 1970. 2. The author's certificate of the USSR N 528628, cl. H 01 H 37 / 76,1974. 3. Authors svdedelstvo USSR on the application N 2988237/07, cl. H 01 H 73/22, 1980.