1. The protection wire shall not pass through the zero-sequence current transformer. When adopting the three-phase five-wire system or the single-phase three-wire system, the protection wire must be connected to the protection trunk of the incoming end of the leakage circuit breaker, and the zero-sequence current mutual inductance shall not be passed in the middle. Device.

2. Single-phase lighting circuit, three-phase four-wire power distribution line and other lines or equipment using the working zero line, the zero line must pass through the zero-sequence current transformer.

3. In the system where the neutral point of the transformer is directly grounded, once the leakage circuit breaker is installed, the working zero line can only be used as the working zero line after passing through the zero-sequence current transformer, and cannot be grounded repeatedly. The working lines of other lines are connected.

4. The electrical equipment can only be connected to the load side of the leakage circuit breaker, and one end is not connected to the load side, and the other end is connected to the power supply side.

5. In the three-phase four-wire or three-phase five-wire system, the three-phase load should be balanced as much as possible in the single-phase and three-phase load.