Circuit and method for distant controlling a plurality of electrical equipments by a pair of push-buttons

Abstract

The invention provides a circuit and a control method for the remote control of a plurality of electrical devices by using a pair of buttons. A power source L1 is connected in series with a circuit terminal 2-4 via an on-site master stop button SB10 and a monitoring room master stop button SB30. The circuit terminal 2-4 is connected in series with a power source N via a monitoring room start button SB20 and the paralleled coil groups of a on-site electric relay KR1-KRn. The circuits of a plurality of paralleled control motor contactors are arranged between the circuit terminal 2-4 and a power supply neutral line NN. The circuit of each control motor contactor is implemented by connecting an on-site start button SB11 in parallel with a pair of movably-engaged self-protection auxiliary contacts KM1-1 of a contactor KM1 and a pair of movably-engaged contacts KR1-1 of the on-site electric relay and connecting in series with a stop button SB21 and the coil of a contactor KM1. The main contactor KM1-2 and the moving contact of each motor contactor are connected with the motor, and the static contact thereof is connected with the power source. The invention can control the plurality of electrical devices in the working place with high safety and reliability and facilitates the installation and maintenance.

Description

technical field [0001] The invention belongs to the technical field of electric drag automatic control, and in particular relates to a circuit and a control method for remotely controlling several electric devices with a pair of buttons. Background technique [0002] At present, at the equipment work site, the basic circuit for starting each motor is: press a start button to electrify the corresponding control contactor coil, the contactor is closed, and the three pairs of main contacts of the contactor are connected to the three-phase power supply. When the motor is running, a pair of auxiliary contacts of the contactor are self-protected, so that when the start button is disconnected, the coil of the contactor can be kept charged through the self-protected contacts, so that the motor runs continuously. When the stop button is pressed or the power grid fails, the contactor coil loses power, the contactor is released, and the motor stops. N sets of such circuits can be used...

AI Technical Summary

Problems solved by technology

[0004] In the existing monitoring room far away from the site, N start buttons and a total stop button are also set for remote control, and these button lines are connected to the above-mentioned N groups of control circuits on the equipment site, so that not only the control buttons There are many, and there are many long-distance cables, high cost, high failure rate, difficult installation, and troublesome maintenance

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