Low-voltage motor protection method and device thereof

Abstract

The invention relates to low-voltage motor protection method and device thereof. The invention relates to a low-voltage motor loop which comprises a circuit breaker and a contactor, wherein the output end of the contactor is connected with the input end of the circuit breaker, and the circuit breaker and the contactor are both connected with the low-voltage motor loop through a microprocessor module, the output end of a current signal detection module is connected with the input end of the microprocessor module, the output end of the microprocessor module is connected with the input end of an action execution module, and the output end of the action execution module is respectively connected with the input ends of the circuit breaker and the contactor. During the operation, the current signal detection module detects electric current in the low-voltage motor loop, and a detection result is transmitted into the microprocessor module for being analyzed and calculated, and the microprocessor module sends an action instruction to the execution module to control the contactor or switch off the circuit breaker. Therefore, the execution of the contactor or the circuit breaker is selected correctly by comparing the electric current acquired by the microprocessor module with the disjunction of the contactor, and consequently, the switching-off when the failure occurs is safer and more reliable.

Description

technical field [0001] The invention relates to an electric protection method and equipment using the method, in particular to a low-voltage motor protection method and its device. Background technique [0002] As far as the existing low-voltage motor is concerned, its working environment is varied. In order to improve the work adaptability of the low-voltage motor, it is necessary to adopt certain protection methods and install certain protection devices. [0003] However, in the existing low-voltage motor protection method and its device, when the fault current in the circuit is between 8 times the rated current and 14 times the rated current, the circuit breaker will not automatically cut off the fault. As a result, the low-voltage motor cannot get the necessary protection. Moreover, combined with the performance of the contactor, forcibly cutting off the fault through the contactor alone will lead to permanent burnout of the contactor, and at the same time fail to achie...

AI Technical Summary

Problems solved by technology

[0003] However, in the existing low-voltage motor protection method and its device, when the fault current in the circuit is between 8 times the rated current and 14 times the rated current, the circuit breaker will not automatically cut off the fault.

As a result, the low-voltage motor cannot get the necessary protection

Moreover, considering the performance of the contactor, forcibly cutting off the fault through the contactor alone will lead to permanent burnout of the contactor, and at the same time fail to achieve the purpose of cutting off the fault, but will lead to the expansion of the situation

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