The so-called leakage circuit breakers are divided into two types: electronic leakage circuit breakers and pure electromagnetic leakage circuit breakers. Their basic principles are as follows:

1. The electronic leakage circuit breaker is a kind of leakage circuit which is composed of several electronic components. When the power supply leaks, it reaches the specified action current, and its output signal pushes the mechanism to break through through the electronic amplification function. Its disadvantages: it needs enough auxiliary power supply, poor anti-interference performance of electronic components, misunderstanding action easily caused by high current impact, aging of electronic components and short service life.

2. Electromagnetic leakage circuit breaker is a kind of mechanical leakage circuit breaker made of high magnetic conducting material, permanent magnetic steel and other metal materials through heat treatment, precise processing and purification. When the leakage reaches the specified action current, it outputs the signal through precise processing of heat treatment, and after purification and assembly, a kind of leakage circuit breaker is broken by a mechanical electric machine driving mechanism.

Its disadvantages: expensive materials, sophisticated technology and high manufacturing cost. But the disadvantages of electronic type are solved. In summary: at present, developed countries such as Germany, the United States, France and other developed countries developed, manufactured and gradually promoted the application of pure electromagnetic leakage short circuit device in the late 1940s. However, developing countries should be constrained by economic conditions. Generally, electronic products are used in industry, mining and housing. However, a large number of coastal developed provinces in China have been engaged in rural network reconstruction projects and construction The selection of pure electromagnetic leakage circuit breaker has made a great contribution to the safe use of electricity. For this reason, article jgj46-2005.8.2.13 issued by the Ministry of construction also expressly stipulates that pure electromagnetic leakage circuit breaker is the first choice product in the construction site of our country. As we all know, the construction site is a specific place, because it is a temporary electricity system, which can not be prepared with the electricity standards of industrial and mining enterprises and residential buildings. Large equipment and equipment have strong liquidity, frequent start-up of large current, and many uncertain factors of electricity load. In this way, there are higher requirements for the leakage circuit breakers at the construction site, only to meet the above requirements, It is safer and more effective to use electricity on the construction site.