One, the introduction

In the process of our country economy high speed development, the frequent of fire caused great harm to the society and public safety, according to the national authoritative department statistics, our country each have more than 30% of the fires are caused by electrical fire, October 1, 2012 - the national total of 110000 cases of fire, electrical fire of 33385, 30.3% of the total.In the number and harm degree occupies other fire first.Electrical fire caused great damage to people and property.Arc fault is one of the main causes of electrical fire, while traditional circuit breakers can only protect the residual current, over current and short circuit, and many serious fire accidents are often caused by the fault of the arc below the rated current.Therefore, it is of great significance to study the cause and monitoring of fault arc.This paper mainly describes the working principle of fault arc detection device and the technical realization of hardware and software of fault arc detection.

Ii. Product overview

2.1 composition of the existing electrical fire monitoring system

The basic components of the electrical fire monitoring system include: electrical fire monitoring equipment, residual current electrical fire monitoring detector and temperature-measuring electrical fire monitoring detector.The system can monitor the current, residual current and temperature in the protected line, and find the hidden danger of electrical fire in time to prevent the occurrence of electrical fire.

The electric fire monitoring system integrates monitoring, alarm, control and centralized management. The monitoring detector is generally connected to a branch of the bus, receives the command of the main controller, and transmits all the information.The master controller processes the received data and monitors the changes in parameters such as single-phase and three-phase current, residual current and temperature of the detected electrical line.When the parameters are abnormal, the remaining current transformer, temperature sensor and other terminal inspection

Measuring element of information collection, and to monitor the detector, exceeds the set value is send out alarm signal, and at the same time to the monitoring device, the further identification decision, when confirm may fire signal from fire alarm monitoring equipment, alarm indicator, send out alarm sound, and displayed on the LCD display and alarm information.

2.2 deficiencies of the existing electrical fire monitoring system

Many serious fire accidents are caused by faulty arcs in lines that are below rated or expected short-circuit current.These dangerous arcs can occur on poorly designed or aged power supply lines, electrical plugs and the power cords of household appliances, internal wiring harnesses or component insulation.When the fault arc occurs, the protection devices such as leakage, overcurrent and short circuit on the line may not be able to detect the fault electricity

Arc or can not quickly move to cut off the power, easy to cause fire.