Low-voltage circuit breaker with terminal block temperature rise monitoring device

Abstract

The invention discloses a low-voltage circuit breaker with a wiring terminal strip temperature increase monitoring device. The temperature increase monitoring device comprises a temperature sensor which is composed of multiple NTC thermosensitive resistors. Each temperature sensing end is fixedly connected to a terminal of the wiring terminal strip through a heat conducting connecting mechanism. Each resistor is provided with an electric connection terminal provided with a path of output temperature vibration analog signal. The resistors are electrically connected with inputting terminals of corresponding paths of a multi-channel electronic analog switch respectively. The latter switches and connects all paths of inputting terminals with an outputting terminal in a circulation mode. An A / D converting circuit provides converted digital signals for a first signal input end of a microcontroller. A coding switch provides a temperature threshold digital signal to a second signal input end of the microcontroller to set the temperature. The microcontroller outputs instructing signals and sends an alarm or a switch control signal which stimulates a circuit breaker body to be disengaged to a control signal output module respectively based on a comparison result of the two signals and simultaneously, outputs instructing signals to a work state indicating module and displays temperature increase variation information of the wiring terminal strip.

Description

technical field [0001] The invention relates to a low-voltage circuit breaker, in particular to a low-voltage circuit breaker with a terminal block temperature rise monitoring device. Background technique [0002] The operating status of a large number of low-voltage circuit breakers has a significant impact on the reliability of the power system. The terminal block is an important part of the connection between the circuit breaker and the power supply line. At present, the common electrical switchgear is mostly connected by screws. Contacts, cable joints, terminals and the busbars connected to them (referred to as "terminals") of the circuit breaker have a relatively high temperature rise and local overheating is a relatively common phenomenon. According to statistics, among the switch faults of distribution voltage levels in my country in recent years, temperature rise faults rank among the top three. The direct reason is that the contact resistance between the terminal a...

AI Technical Summary

Problems solved by technology

The control output mode of this temperature control switch is not compatible with the existing tripping device of the circuit breaker. If it is necessary to directly control the tripping of the circuit breaker, a special tripping device must be added, which leads to the complexity of the circuit breaker structure.

Moreover, this prior art can only indicate whether the temperature reaches the threshold, but cannot indicate the dynamic change of the temperature rise, so real-time and dynamic detection of the temperature rise cannot be realized.

Furthermore, its output signal cannot be connected to a host computer such as the central control room, and its control output signal cannot be used for digital intelligent management and control systems

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