SU1462448A1 - Electric motor complete with protection and control units - Google Patents

Abstract

The invention relates to electrical engineering and can be used to protect electric motors against Heci. symmetric modes of operation. The aim of the invention is to protect electrical installations from breaks and phase misalignment without false alarms. The goal is achieved due to the fact that between neutral three-phase electric motor and grounded neutral wire includes -1.c additional winding II, wound on one core with winding 10 magnetic actuator, providing switching on and off of the electric motor, counter to the latter. Additional winding is normally shunted by fuse or by-. hank additional relay. When an asymmetry occurs in the supply network in the neutral of the electric motor, a voltage and an asymmetry current arise. Additional current is shunted by this current. The winding 11 is defective when the fuse blows or when the contact 15 is opened. The additional winding demagnetizes the magnetic starter, and it disappears, thereby disconnecting the electric motor from the mains. 2 Il. WITH/)

Description

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The invention relates to the field of electrical engineering and can be used to protect electrical installations from dangerous discontinuity modes (skew) phases.

The device operates at phase distortions that are not dangerous.

The aim of the invention is to protect electrical installations from clipping and skewing of fae-bee false alarms.

Figure 1 and 2 shows the scheme of the proposed device.

The device in figure 1 contains a motor with windings 1-3, connected to a three-phase network through the contacts of the magnetic actuator 4-6, one end of the Start button 7 is connected to the contact of the magnetic actuator 6 on the supply side, and to the same magnetic contact on the side of the electric motor the actuator is connected to one of the pins of the 8 Stop button connected to the first output of the signal lamp 9, the second OUTPUT of which is connected to the second output of the 7 Start button and to the first view of the main winding 10 of the magnetic actuator, the second output of which is connected to zero one motor terminal, one additional winding 11 winding wound on one magnetic core with the main winding 10 of the magnetic starter, the second terminal of which is connected to a specific neutral wire 12, between the zero output of the electric motor and a specific zero wire 12 is connected to the zero motor output ,

The device in Fig, 1 works as follows.

If an asymmetrical mode occurs for any reason, a voltage arises in the motor neutral and an asymmetry current passes through the fuse 16, the fuse 16 blows from passing the iesymmetry, as a result of which the asymmetry voltage is applied to the additional winding 11, the additional winding 11 is wound. - the conductor with the winding 0 of the magnetic starter, and the winding of the windings is opposite. From the asymmetry voltage applied to the winding 11, the magnetic circuit of the magnetic actuator is demagnetized and it disappears and opens the force

the motor contacts are disconnected from the mains.

The device on fnig.2 contains an electric motor with windings 1-3, connected to a three-phase network through the contacts of the magnetic actuator 4-6, one end of the Start button 7 is connected to the contact of the magnetic actuator 6 on the mains side of the power supply, and from the side of the electric motor the actuator is connected to one of the pins of the button S Stop connected to the first end of the signal lamp 9, the second output of which is connected to the second output of the Start button 7 and the first output of the main winding 10 of the magnetic actuator, the second output of which is connected to the left terminal of the electric motor, one of the terminals of the additional winding 11 is connected to the zero terminal of the electric motor, the second output of the additional winding 1I is connected to the grounded neutral wire 12,

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between the zero terminal of an electric motor and a grounded neutral wire

12 includes a series circuit consisting of a winding 14 wound on a single magnetic core with a winding 13, and an opening contact 15.

The device works as follows.

When an asymmetry occurs, an asymmetry voltage arises, and an asymmetry current passes through the neutral of the electric motor to the neutral wire. The asymmetry current spreads in parallel circuits from windings 11 and 13 and winding 14 and contacts 15. From the unbalance current passing through windings 13 and 14, contact 15 is disconnected from a separate relay. In this case, one of the parallel circuits is broken and the total asymmetry current passes through the windings 11, and 13. From this total asymmetry current, the winding

13 demagnetizes the magnetic system of the actuator 10 and it disappears, providing the disconnection of the electric motor from the network by contacts 4-6.

Invention formula

Claims (2)

1. Electric motor with a protection and control unit, made in the form of a magnetic starter, the closing contacts of which are intended to connect the electric motor to mains, and one output of the main winding of the magnetic starter is connected to the connection terminal to one of the phases, the mains supply through the Start button on the supply side and through the signal lamp and the Stop button on the line of the motor terminals, and the other output of the main winding of the magnetic starter is connected with a terminal for connecting to the zero terminal of an electric motor, a fuse, the terminals of which are connected by terminals for connecting to the zero terminal of an electromotor and to a grounded neutral wire of the electrical cable ovki, characterized in that, in order to protect the motor from breaking and phase imbalance without false positives, magnetic starter protection and control unit is provided with an additional winding, the conclusions of which are intended for connection to the zero leads of the electric motor and to the grounded neutral wire, while the additional winding is wound oppositely with the main winding of the magnetic starter on a common magnetic conductor. 2. Electric motor according to clause I., which is characterized in that the protection and control unit is additionally equipped with a relay with main and additional windings, with one output of the main winding of the relay connected to the outputs of the additional winding of the magnetic starter, and the other output connected to the terminal for connection to a grounded neutral wire, and one extra winding relay output is connected to the main terminal winding of the magnetic starter, and the other through the break contact is connected to the terminal for connection to a grounded neutral wire.