3P leakage switch for protecting leakage circuit breaker of three-phase submersible pump. The neutral line (n) is unnecessary, and the protection line (PE) is directly connected to the submersible pump shell, and it is not allowed to pass through the leakage switch.

Leakage switch is a kind of switch, which is mainly used to prevent leakage accidents. The working principle of the switch is that there are two windings on the iron core, a primary winding and a secondary winding. The main winding also has two windings: the input current winding and the output current winding. When there is no leakage, the input current and the output current are equal, and the vector sum of the two magnetic fluxes on the iron core is zero, so the potential will not be induced on the secondary winding, otherwise an induced voltage will be formed on the secondary winding, and the actuator will be driven by the amplifier to trip the switch.

Connection of leakage switch. Open-phase switch is a three-phase four-wire switch, which is widely used now. There are three fire lines (yellow, green and red) and a zero line (blue). The voltage between the three live wires is 380 volts, and the voltage between each live wire and the neutral wire is 220 volts. Single-phase leakage switch is generally wired, it says left zero and right fire, just follow the wiring. Whether it is a three-phase or a single-phase leakage switch, it is: on-line, off-line.