Self-checking protective device of motor before starting

Abstract

The invention discloses a self-checking protective device of a motor before starting. The self-checking protective device comprises an MCU (multipoint control unit) module, a communication interface circuit, a display and keyboard circuit, an input and output isolation interface circuit, a winding resistance value measuring circuit and a DC high-voltage generation and insulation resistance measuring circuit, wherein bidirectional connection is all adopted between the MCU module and the communication interface circuit, between the display and keyboard circuit, between the input and output isolation interface circuit, and between the winding resistance value measuring circuit and the DC high-voltage generation and insulation resistance measuring circuit. The self-checking protective device is installed in a starting circuit of a motor, can determine whether the motor is normal by measuring the winding resistance value and the insulation resistance of a winding before starting, and then starts the motor or sending out alarms to stop the starting.

Description

technical field [0001] The invention relates to a protection device for a motor, in particular to a self-test protection device before starting the motor. Background technique [0002] There is generally no way to know the state of the current motor before starting, and there is no real-time detection device. The motor may work in a humid working environment, and the insulation performance between the windings of the motor and between the windings and the ground may deteriorate, and the motor starts. When the instantaneous current reaches 3-5 times of the rated value, the circuit breaker may be knocked off, and the equipment may be damaged in severe cases. However, it is difficult for the general motor protector to play a protective role in this case, which may cause accidents. . Contents of the invention [0003] The technical problem to be solved by the present invention is to provide a motor self-check protection device before starting that can detect the motor wind...

AI Technical Summary

Problems solved by technology

[0002]The state of the current motor before starting is generally unknown, and there is no real-time detection device. The motor may work in a humid working environment, and the windings of the motor and the The insulation performance between the winding and the ground may deteriorate, and when the motor starts, the instantaneous current reaches 3-5 times the rated value, which may cause the circuit breaker to be knocked off, and in severe cases, the equipment may be damaged, but the general motor protector In this case, it is difficult to play a protective role, causing accidents

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