RU1823116C - Device for control over asynchronous reversible motor - Google Patents

Abstract

Usage: in electric drives of general industrial mechanisms. SUMMARY OF THE INVENTION: It is to achieve higher reliability by avoiding turning on the electric motor when one of the phases of the supply network is cut off. 1 ill.

Description

From "zregene refers to electrical engineering and can be used in reversible electric drives A of general industrial mechanisms

The purpose of the invention is to increase reliability.

The drawing shows a circuit diagram of the proposed device for controlling an asynchronous reversible electric motor.

A device for controlling an asynchronous reversible electric motor 1 comprises a magnetic starter with a coil 2, power contacts 3, 4 and 5 included in the power supply circuit of the stator winding of the electric motor 1, opening block contact 6 and closing block contact 7, magnetic starter with coil 8, power contacts 9, 10 and 11 included in the power supply circuit of the motor winding 1, opening block contact 12 and closing block contact 13, start button 14 with forward contact 15 and opening contact 16, start back button NO contact 18 and NC contact 19 / button 20 Stop

capacitor 21, which is drawn in the form of a contact contact loop, The first terminals of coils 8 and 2 of the magnetic starters are connected via phase 20 to Stop button C. The second terminal of coil 2 of the magnetic starter is launched forward through series-connected contacts 12, 15, 19, 18, 16 and 6 connected to the second output of the coil 8 of the magnetic starter Start back. The connection point of the contacts 18 and 19 through the capacitor 21 is connected to the phase B of the mains The connection point of the contacts 12 and 15 through the contact 7 is connected to the phase A of the mains, which through the contact 13 is connected to the connection point of the contacts 6 and 16.

The device operates as follows: To turn on the motor 1 for rotation, forward, press button 14 Start forward, along the circuit: phase C, button 20, coil 2 of the magnetic starter Start forward, contact 12, contact 15, contact 19, capacitor 21, phase B receives power winding 2, the magnetic starter trips, closing contacts 3, 4 and 5, ensuring that the motor 1 is turned on for w

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nor Forward, in this case, contact 6 opens, except for starting the magnetic starter Start, and contact 7 closes, while coil 2 receives power through the circuit: phase A. contact 7. contact 12, coil 2. button 20 Stop, phase C,

To turn on the electric motor 1 for rotation, press the Start button 17 backward, along the circuit: phase C. button 20 Stop, coil 8 of the magnetic starter Start back, contact 6. contact 16, contact 18. capacitor 21, phase B receives power from winding 8. The magnetic starter is activated by closing its contacts 9, 10 and 11, enabling the motor 1 to rotate backward, while the contact 12 is opened, excluding the start of the magnetic starter, and the contact 13 is closed, while the coil 8 is powered by the circuit: phase A Pin 13 Pin 6 Failure 8 of the magnetic starter Start back, button 20 Stop, phase C.

If there is no voltage in any of the phases of the supply network, the magnetic starter will not operate.

To disconnect the motor 1, press the Stop button 20, while the switched on magnetic starter (its winding) loses power and its power contacts open, disconnecting the motor from the mains.

In order to increase the speed of the device to turn on, the capacitance of the capacitor can be selected so as to ensure voltage resonance. In this case, the capacitance of the capacitor 21 is determined by the expression

I

(2 g) h

where C is the capacitance of the capacitor 21;

L is the inductance of the coil of the magnetic starter:

f is the frequency of the supply network.

Higher reliability due to the exclusion of turning on the motor when one of the phases of the supply network is disconnected is the advantage and advantage of the proposed technical solution in comparison with the prototype

Claims (1)

The claims A device for controlling an asynchronous reversible electric motor containing the first and second magnetic starters with a coil and three power contacts for connecting the stator winding of the electric motor, each with opening and closing block contacts, the Start and Start back buttons, made in the form of a closing and opening contact groups, the first conclusions of the magnetic starter coils through the Stop button are connected to the clamp intended for connection to the first phase network, the second terminal of the winding of the first starter through a series-connected disconnecting block contact of the second starter, the closing contact of the button Start, the opening contact of the button, the Start back, closing contact of the button The forward start, opening block contact of the first starter is connected to the second terminal of the winding of the second starter, characterized in that, in order to increase reliability by eliminating the inclusion an electric motor, when one of the phases of the supply network is interrupted, a capacitor is introduced through which the common connection point of the contacts of the Start button back is designed to connect to the second phase of the network, point the connection of the opening blocking contact of the second starter with the closing contact of the Start button is connected through the closing blocking contact of the first starter with a clip designed to connect to the third phase of the network, the connection point of the opening blocking contact of the first magnetic starter with the opening contact of the Start button is connected to one output terminal a contact block of a second contactor, the other terminal of which is intended to be connected to a third phase of the network. g l 0