RU70048U1 - AUTOMATIC SWITCH - Google Patents

Abstract

The switch is automatically designed to protect three-phase electrical circuits with a zero wire from short circuit currents. The release in the neutral wire (9) of the switch contains a magnetic circuit (10), a magnetizing winding (11), an armature (13) with a pusher (15), a spring-loaded spring (14) and the output terminals of the release in the neutral wire (16), with which it electrically connected to the neutral wire of a three-phase electrical circuit. The pusher (15) acts on the trip rail (17) of the free trip mechanism. By pressing the button (19), the fixed (3) and movable (4) contacts are brought into contact. If one of the phases breaks or a short circuit occurs between the two phases, the release in the neutral wire is activated, the armature (13) moves, moves the pusher (15), which, through the trip rail (17), triggers the free trip mechanism (18). The switch trips and opens the electrical circuit. The circuit breaker is re-activated by pressing the button (19).

2 ill.

Description

The invention relates to low-voltage apparatus engineering, in particular to automatic circuit breakers with natural air cooling and direct manual control, designed to protect three-phase electrical circuits with zero wire from short-circuit currents. The circuit breaker ensures that the electrical circuit is disconnected when one of the phases is interrupted or a short circuit occurs between the two phases of the electrical circuits with a zero wire.

Automatic switches AP50 are known, developed by the Kursk Electric Appliance Plant (currently OJSC Elektroapparat) and described in the book of L. A. Rodshtein “Low-voltage electrical apparatus”. M.-L.: Ed. Energy, 1964

Automatic switches АП50 for currents 50А, in electric circuits for a rated voltage of 380 V AC, frequencies of 50 Hz and 220 V DC, provided protection against short circuits and overloads.

The disadvantages of this automatic switch are: a large error of operation, a complex design, a large material consumption of the product, the complexity of its manufacture. The circuit breakers are unstable under current.

It was possible to improve the product in the design of automatic switches AP50B (TU 16-522.139-78), which are also the development of specialists of the Kursk Electric Equipment Plant (OJSC Elektroapparat) (see. Index “Catalogs and Directories on Electrical Engineering”. M .: Informelectro).

AP50B circuit breakers for currents up to 63A are designed for installation in electrical circuits for a rated voltage of up to 500 V AC, frequencies 50-60 Hz and 220 V DC, to protect against overloads and short circuits and on / off switching of these circuits with frequencies from 6 to 30 inclusions per day, including for starting, protecting and turning off electric motors.

The design of the automatic switch AP50B, designed to protect against short circuit currents and overload currents, selected for the prototype, contains a housing consisting of a cover and a base. The contact system of the circuit breaker consists of a pair of fixed and movable contacts in each pole. In this case, the fixed contact is electrically connected to the output terminals for connecting voltage to the automatic switch. An arcing chamber with arcing lattices is installed on a fixed contact using a special mount. The movable contact is mounted in the holder with the possibility of rotation and is electrically connected through a flexible current lead to the electromagnetic and thermal maximum current releases and terminal clips of the switch. The tripping of the circuit breaker is carried out using the free trip mechanism, made in the form of a system of articulated levers connecting the on and off buttons of the circuit breaker with a movable contact unit, and disconnecting the rail through which the electromagnetic and thermal maximum releases act on the free trip mechanism.

The disadvantage of this design is that when the circuit breaker is installed in a three-phase circuit with a zero wire, in the event of a break in one of the phases or a short circuit between the two phases, the circuit breaker does not disconnect the electric circuit.

The task to which this technical solution is directed is to create a circuit breaker installed in a three-phase electric circuit with a zero wire, which provides shutdown when one of the phases breaks or a short circuit between the two phases.

The proposed automatic switch contains a housing consisting of a cover and a base, arcing chambers in each pole, a contact system consisting of a pair of fixed and movable contacts in each pole. The fixed contact is electrically connected to the output terminals for connecting voltage to the automatic switch. The movable contact is mounted in the holder with the possibility of rotation and is electrically connected through a flexible current lead to the electromagnetic and thermal maximum current releases and terminal clips of the circuit breaker. At the same time, the thermal maximum release in each pole is electrically connected to the current lead of the movable contact, and on the other hand, to one end of the magnetizing winding of the electromagnetic release, the other end of which is connected to the output terminals of the switch to connect the load from the consumer. The mechanism of free uncoupling is made in the form of a system of pivotally connected levers connecting the on and off buttons of the circuit breaker with a movable contact unit, and disconnecting the rails in the form of a two-shouldered lever, on one arm of which the disconnecting element of the thermal release acts, and on the other arm the disconnecting element of the electromagnetic release . What is new in the design of the circuit breaker is that a trip in a neutral wire is installed in one of the poles of the circuit breaker. The trip in the neutral wire contains a magnetic circuit with a magnetizing winding, an armature, a pusher and terminal clips. Using the clamps, the release in the neutral wire is electrically connected to the neutral wire of the three-phase electrical circuit.

The proposed solution made it possible to install an automatic switch in three-phase electric circuits with a zero wire and to disconnect the circuit when one of the phases is broken or a short circuit occurs between the two phases.

Figure 1 - General view of the circuit breaker;

Figure 2 - trip in the neutral wire.

The circuit breaker has a housing consisting of a cover 1 and a base 2. On the base 2, a contact system is installed, consisting of a fixed contact 3 and a movable contact 4. The fixed contact is electrically connected to the output terminals 5 for connecting voltage to the circuit breaker. The movable contact 4 is mounted in the holder 6 with the possibility of rotation and is electrically connected through a flexible current lead 7 to an electromagnetic maximum current release (not shown) and a thermal release 8 and terminal clips of the circuit breaker. In one of the poles of the switch, a trip unit is installed in the neutral wire 9. The trip device in the neutral wire 9 contains (see FIG. 2) a magnetic circuit 10 with a magnetizing winding 11 mounted on the frame 12. Anchor 13 is spring-loaded with a spring 14 and moves the pusher 15. The release is in zero the wire also contains terminal clips 16, with which it is electrically connected to the neutral wire of a three-phase electrical circuit. The pusher 15 acts on the trip rail 17 of the free trip mechanism, made in the form of a system of pivotally connected levers 18 connecting the on / off buttons 19 and 20 of the circuit breaker 20 with a movable contact 4.

The circuit breaker is installed in a three-phase electrical circuit with a zero wire. In this case, the release in the neutral wire 9, installed in the closest to the control mechanism of the switch

pole, connected to the gap of the neutral wire using the output terminals 16.

By pressing the button 19, fixed 3 and movable 4 contacts are brought into contact. In this case, a current flows from the terminal 5 through the switch through the fixed contact 3, the movable contact 4, the current lead 7 to the second terminal of the switch. When short-circuit currents in the circuit protected by the circuit breaker are reached, the setpoint current of the electromagnetic maximum current release is reached and the trip rail 17 is deployed, triggering the free trip mechanism 18. The circuit breaker automatically trips and opens the electric circuit. When overload currents is triggered thermal release 8, the switch is activated and opens the electric circuit.

When one of the phases in the line breaks, a surge current passes through the release in the neutral wire 9. When the current value is equal to 1.4 In, the armature 13 is pulled under the action of electromagnetic forces, strikes the pusher 15, the release in the neutral wire 9 is activated and, using the free trip mechanism 18, the circuit breaker disconnects the circuit.

Claims (1)

An automatic switch comprising a housing consisting of a cover and a base, arcing chambers in each pole, a contact system consisting of a pair of fixed and movable contacts in each pole, while the fixed contact is electrically connected to output terminals for connecting voltage to the automatic switch, and the movable the contact is mounted in the holder with the possibility of rotation and is electrically connected through the flexible current lead to the terminal clips of the circuit breaker, electromagnetic and thermal ma by maximum current releases acting on the disconnecting rail of the free trip mechanism, made in the form of a system of pivotally connected levers connecting the on and off buttons of the circuit breaker with a movable contact assembly, characterized in that a trip in the neutral wire is installed in one of the poles of the circuit breaker, containing a magnetic circuit with magnetizing winding, anchor, pusher and output terminals of the release in the neutral wire, with which it is electrically connected to the neutral wire of a three-phase electric cal chain.