1. When powered on and measured with an electric pen, the live wire will light up.

2. Disconnect the zero wire, only connect the live wire, turn the home light on, measure with an electric pen, and the other one that will light up is the zero wire.

3. The rest is the ground wire.

The household electricity is generally 220V~250V Single-phase electric power, which can work normally only after the live wire passes through the load such as bulbs and other electrical appliances and forms a loop through the zero wire. Some electrical appliances with metal shells also need to be connected to a grounding wire, which can be led to the ground in case of accidental electrification of the electrical shell, ensuring electrical safety.

1. The correct connection method is: the phase line (L) is generally red or brown; The zero line (N) is blue or green in color; The color of the protective ground wire (PE) must be yellow and green

2. Can you use a clamp type Ammeter to measure the live wire with an electric pen? The current of the phase wire (live wire) and the zero wire is the same, and there is no current when the ground wire is normal.

3. The zero line has current flowing through it; The ground wire is used for protection, and there is no current during normal operation. Only when there is a short circuit or leakage, there is current. The grounding resistance is required to be very small, and the equipment end is generally grounded by the protective shell.

Use an electric pen to measure the live wire, and place the test light (with a wire bulb) on one of the live wires and the other two wires. If the light is on, it indicates that it is a 0 wire. If the light is on or off. It indicates that it is a ground wire. (The lamp test method is effective when the ground wire is not connected to the ground. If the ground wire is connected to the ground, the lamp will light up regardless of which line it is connected to.)

4. In the presence of a power source, it should not be difficult to find the live wire. The difficulty lies in distinguishing between the zero wire and the ground wire. In theory, the voltage between the live wire and the zero wire is 220 to the right, and the voltage between the live wire and the ground wire is about 190 volts. If you connect an energy-saving lamp, the brightness should be visible, and the bright one is naturally the zero line, for reference only.

5. There's another simple way

We use a test light (with a wire bulb) to connect it to one of the live wire and the other two wires. If the light is on, it indicates that it is a 0 wire. If the light comes on, the leakage switch will trip. It indicates that it is a ground wire.