DZ47 circuit breaker with leakage protection has not only single phase, but also three phases. The picture you provided shows the single-phase leakage protection circuit breaker produced by Zhengtai Group. On the upper left are the two terminals of the power supply incoming line, the phase line connected to the power supply on the left (commonly known as live wire) and the neutral line connected to the power supply marked with the letter N on the right (commonly known as "zero line", which is actually an irregular name). On the lower right are the two terminals of the load terminal outgoing line, the phase terminal on the left and the neutral terminal on the right, which are marked with the letter N next to them. There is the word "C6" under the trademark of the circuit breaker, which indicates that the maximum allowable load current of the circuit breaker is 6 A (C is short for current in English). Use and maintenance: 1. The orange button directly above is the test button. When the test button is powered on, it will trip. If it does not trip, it means that the leakage circuit is invalid and needs to be replaced and repaired. 2. In order to ensure the safe use of electricity, users are required to do a test once a month or so, so that problems can be found and solved in time. 3. In normal use, once a trip occurs, first check whether there is serious overload and leakage in power consumption. If there is nothing found, reset and close the circuit breaker: first press the small blue square button below, and then close it. If you can't close the brake, jump down immediately after closing it (it's not buckled). At this time, you need to find a professional to check and repair it. This is my professional answer. Reply to my request for revision again: This is already very detailed. I have been in electric power for more than 3 years, and all the students are engineers. I don't know how detailed this simple project is!