This is a three-phase alternator. Use a multimeter to measure the resistance of the four terminals. You can distinguish which one is the neutral line (the red test lead is connected to the neutral line, and the black test lead measures). the resistance of the other three lines. If the values are the same, the red test lead is the neutral wire and the other three are live wires.)
There are two ways to connect: one is to use a live wire and a neutral wire to connect a diode to 12 volts charging the battery; the other is to use three live wires connected to a three-phase bridge rectifier to produce 12 volts DC to charge the battery.
In addition, you can also use a live wire and a neutral wire to directly connect the car headlights for lighting purposes.
As shown on the switch, L1, L2 and L3 are phase lines and N is the neutral line.
The bornThe upper terminal of the switch is connected to: A, B, C, N (to the power supply), the lower terminal of the switch is connected to: A, B, C, N (to the load), 4P circuit breaker with leak. The three-phase leakage protection is connected to 4 wires (3 live wires and 1 zero wire), and the three-phase air circuit breaker is connected to 3 live wires. There are 2 single-phase leakage protection wires (1 live and 1 zero), and the single-phase air circuit breaker is connected to 1 live wire.
Detailed information:
Three-phase four-wire consists of three live wires and a neutral wire composed of lines. There are two types of connection: star connection and delta connection. The star connection method is generally used.
When the three-phase alternator supplies power to the outside world, connect the X, Y and Z ends of the three sets of coils together and draw ae line from the connection point. This line is called. the neutral line, also called the neutral line. Next, pass a wire to the other ends A, B and C of the winding. This forms a three-phase, four-wire system (three live wires and one neutral wire). This connection method is called star connection.
Since the three-phase four-wire power supply can supply two different voltages of 220V and 380V at the same time, it is widely used. The star connection is represented by Y, also called a Y connection.
If the neutral line is not pulled and three wires are used to power the exterior, it is called a three-phase three-wire system .
Reference link: Baidu Encyclopedia - Three-phase four-wire