SU1307519A1 - Control device for induction reversible electric motor - Google Patents

Abstract

The invention relates to electrical engineering and can be used in electric drives of general industrial mechanisms. The aim of the invention is to increase reliability. This goal is achieved due to the fact that the contacts of the trip switches at the time of their closing do not pass, and when they are opened, they only switch the current to hold the contactors in the on state, which is less than the current they turn on, which dramatically increases durability and reliability contacts of limit switches and allows control with relatively low-power limit switches made on reed switches, I il. so about

Description

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The invention relates to electrical engineering and can be used in electric drives of general industrial mechanisms.

The aim of the invention is to increase reliability.

The drawing shows a diagram of the device.

The device for controlling the reversible asynchronous electric motor contains Forward and Pa rear contactors, coils 1 and 2 of which are connected by one pins and intended to be connected to one of the phases of the power supply, the other pins from each of the coils 1 and 2 of the Forward and Back contactors are connected respectively to one the opening contacts 3 and 4 of the opposite contactor, the opening contacts 5 and 6 and the closing contacts 7 and 8 of the control buttons: Start forward and Backward interlocked; one output of the control button 9 Stop; En for connection to a different phase of the power source, another terminal of the control button 9 Stop is connected to the common connection point of one terminals of the closing contacts 7 and 8 of the control buttons. Start and Start backward one terminal of the coil 10 of the relay is connected to the same terminals of coils 1 and 2 of the contactors. and Back, another output of the coil 10 of the relay is connected to one output of the closing contact 11 of the relay, with the other outputs of the closing contacts 7 and 8 of the control buttons, Start forward and Start reverse, are connected to one of the outputs corresponding to

The tapping contacts 5 and 6 of these control buttons, the other terminals of which through limit switches 12 and 13 are respectively connected to the other terminals of the opening contacts 3 and 4 of the contacts, another terminal of the relay contact 11 are connected to another terminal of the control button 9 Stop.

The device works as follows.

When the supply voltage is applied, the coil 10 of the relay and the coils 1 and 2 of the contacts are provided. When briefly pressed, for example, the j button with the contacts 5-7, the contact 7 is closed and the contacts 5 are opened. At this, the contacts 7 and 6, 13, 4 and the coil 2 of the contactor 3 flow through the current,

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The coil 2 is triggered by the contactor 3, which opens its contact 3. At the same time, the coil 10 of the relay closes shortly through contact 7, closes its contact 11. Due to this, when contact 7 returns to its initial state, i.e. opening them, the coil 2 of the contactor and the coil 10 of the relay are kept on. The power contacts of the coil 2 of the contactor turn on the electric drive in the forward direction of rotation. Since pin 3 is open, coil 1 of contactor 3 is off. When contactors 8 and 6 are closed, the power supply circuit of coil 2 of contactor 3 is opened by contact 6, coil 2 of contactor is turned off, and its contact 3 is closed. The contactor coil 1 is turned on and the electric drive rotates in the opposite direction. Since the contact 4 of the coil 1 of the contactor opens, the coil 2 of the contactor does not turn on even after closing the contact 6 of the control button. The disconnection of any of the contactors is carried out by briefly opening the Stop control button 9, the device provides zero protection of the electric drive, i.e. in case of short-term voltage disappearance in the network, the coil 10 of the relay is disconnected, the contact 11 is opened, and any of the coils 1 or 2 of the contactors is turned off, and when voltage is applied to the network it does not automatically turn on.

The device provides control of the electric motor not only with the help of the control buttons, but also with the limit switches 12 and 13, which automatically reverse the electric drive when any drive mechanism is affected. If coil 2 of the contactor is turned on using contact 7 of the button, then when the contacts of the limit switch 13 are opened, the coil of the contactor is turned off, its contact 3 is closed, because of the contactors of coil 1 through the closed contactors 11, 5, 12 and 3. The drive reverses and begins to rotate in the opposite direction. Since the contact 4 is open, the coil 2 of the contactor does not turn on even after the contacts 13 have returned to their initial state. When the pins 12 of the other limit switch is open, it will turn off

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the coil 1 of the contactor is turned on and the coil 2 of the actor's contact is turned on. Further operation of the device is repeated.

In the device, at the moment of their closure, the current does not pass through the contacts of the limit switches, and when they are opened, they switch only the holding current of the contactors in the on state, which is an order of magnitude lower than their switching current, which dramatically increases the durability and reliability of the track contacts switches and. allows control using relatively low-power trip switches made on reed switches.

Claims (1)

Claim 1 A device for controlling a reversible asynchronous electric motor containing Forward and Backside contactors, the coils of which are connected by one output and intended to be connected to one of the phases of the power source, the other terminals of each of the coils of the Forward and Backside contactors are respectively connected to the same opening contacts of the opposite contactor, open and close buttons 194 control forwards and reverses are interlocked, one pin of the control button Stop is designed to connect to another phase of the power source, another pin of the control button Stop is connected to the common connection point of one pin of the closure contacts of the control buttons forward and rewind, two limit switches differing from In order to improve reliability, a relay with a closing contact is inserted into it, one output of the relay coil is connected to the combined terminals of the contactors of the Forward and Back contacts, the other output of the coil is relays It is connected to one output of the closing contact of the relay, with other outputs of the closing contacts of the control buttons Forward and Back start, connected to one terminals of the corresponding disconnecting contacts of these control buttons, the other terminals of which are connected to other contacts of the contactors, respectively, to other terminals, another terminal the closing relay contact is connected to another pin of the Stop control button, Compiler E.Peremyslova Editor A.Gulko Tehred V.KadarKorrektor T. Kolb Order 1638/52 Circulation 661 Subscription VNIIPK USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4