Single-phase leakage maintainer (made up of miniature-circuit-breaker)can not be connected to the three-phase four-wire circuit. The technique has specialized, single-phase leakage switch MCB in the leakage maintenance device inside the zero-sequence current transformer detection is a phase line (front) and a null line of the remaining current vector, once the leakage current exceeds 30mA, through the terminal to execute the tripping device, forcing the internal tripping system action, to achieve the maintenance role.
The wiring diagram of 2P leakage switch as shown below:
Single – phase leakage protector can be connected to the three – phase four – wire circuit
Single-phase leakage switch has phase line and null line control, there are separate phase line control. Although there is a null line in the three-phase four-wire power supply, it can be composed of 220V voltage with three phase lines arbitrarily, but it can not control the other two phase lines.
The wiring diagram of three-phase four-wire leakage switch is shown in the figure above.
3P + N power supply input wire only need to know that the neutral wire is connected to N, and other L1, L2, L3 can be connected to the wiring terminal.
3 p + N leakage of maintenance of N line is straight (no matter whether is separately in the channel state), the connection must be ahead on the left side, the null line by line in the N, if N wire fault into the front is unable to maintain the tripping circuit continuous have electricity maintenance.