SU1415390A1 - Device for automatic repeated three-phase energization of induction motor - Google Patents

Abstract

The invention relates to electrical engineering and can be used to automate the power supply of AC motors. The aim of the invention is to increase reliability. The device allows self-starting of the electric motor1 after a long interruption in the power supply with a control of the quality of the restored voltage. This is achieved by connecting the coils of the magnetic actuator 1 and the coil 8 of the time relay to different phases of the supply network, the coil 8 of the time relay being connected via a variable resistor 9 and the tripping block contact 5 of the magnetic actuator. The start-up, as well as the repeated self-starting of the electric motor occurs when the control key 6 is closed (with locking of the closed position) only if there is voltage in all three phases of the power supply network. 1 il. (t (L

Description

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The invention relates to electrical engineering and can be used to automate the power supply of AC motors.

The aim of the invention is a noBbmie reliability

The drawing shows a schematic diagram of the device.

The device contains a magnetic starter with a coil 1, three power contacts 2, some of the outputs of which are intended to be connected to the stator winding phases of the electric motor 3, and others to be connected to the phases of the power source, closing auxiliary contact 4 and disconnecting auxiliary contact 5, control key with closing contact 6 with latching on position, time relay with closing contact 7 with time delay for opening, the coil 8 of which is connected to one output of variable resistor 9 by one output, one output is closed The control key 6 is connected to the first phase of the power supply, another output of the closing contact 6 of the control key is connected to one output 3n1 of the time relay contact 7 and connected to a single coil 1 terminal through the closing block contact 4 of the magnetic trigger; another which is intended for

connecting to the second phase of the power source, one output of the tripping block contact 5 of the magnetic starter is connected to another output of the coils 8 of the time relay, another output of the variable resistor 9 is connected to one output of the closing contact 7 of the time relay, the other output of which is connected to one output of the cat; P1 ki 1 magnetic starter, another pin disconnecting block contact 5 magnetic starter is designed to connect to the third phase of the power source.

The device works as follows.

When the control terminal 6 is closed, power is supplied to the turn-off coil 8 through a variable resistor and a closed block contact 5 of the magnetic starter. The time relay is triggered and its contact 7 energizes the coil 1 of the magnetic starter, which operates, closes the power contacts 2, connects the electric motor 3 to the power source, closes

53902

block contact 4, providing self-powering, and opening the block contact 5, spreading the jBaBaH power circuit of the coil 8 of the time relay, contact 7 of which opens with a time delay.

In the case of a deep decrease in voltage or its complete disappearance, the magnetic starter is turned off once; .; j closes its pins 2, disconnecting the motor from the power source, opens the blocking contact 4 and closes the blocking contact 5,

When restoring voltage

i вновь re-triggers the time switch and the magnetic starter turns on, connecting the electric motor 3 to the power source.

If the voltage level of the engine fails to start reliably, the time relay will not turn on and the motor will not start. With an incomplete phase voltage recovery, the self-start will not occur,

25 since either the time relay or the magnetic starter does not turn on.

Thus, the device allows the automatic re-start of the electric motor after

30 long interruption of power supply with quality control of the recovered voltage.

Claims (1)

Invention Formula A device for automatic three-phase re-activation of an asynchronous electric motor containing a magnetic starter with a coil, three power contacts, some of which are designed to be connected to the phases, the stator winding of the electric motor, and others to be connected to the source of the pi5 source five tani, and closing the block-contact. a control switch with a closing contact with a locked position, a time relay with a closing contact with an open time delay, the coil of which is connected to one output terminal of an alternating resistor by one VT, one output of the closing contact of the control key is connected to the first phase of the power supply, the other closing contact the contact of the control key is connected to one output of the closing contact of the time relay and through the closing block contact of the magnetic start3U15390 The body is connected to one side of the coil, the other is the variable resistive starter, the other side of the resistor is connected to one side, and the rear side is connected to one side of the power supply. The fact that, with it the magnetic coil spindle output — in order to increase reliability, the magnetic body, the other output of the blocking starter, is equipped with the magnetic starter opening contact of the magnetic starter, is a pre-contact, one ene for connection to a third phase nen to the other terminal Q of the power supply relay coil.