How to distinguish between live wire ground wire and zero wire using a multimeter
1. Using a capacitive pen for testing:
When tested with an electric pen while powered on, the live wire will light up; After determining the live wire, connect the remaining two wires to the 220V light bulb, then connect the live wire and power it on. The bright one is the zero wire, and the dark one is the ground wire.
2. Color analysis of wiring:
Under standard circumstances, warm color blending lines (red, orange, yellow, etc.) are hot lines; The cold tone line (black, brown, blue, etc.) is the zero line; The yellow and green interlaced (flower thread) is the ground wire.
3. Judging by the position of the socket hole:
On a three hole socket, under standard circumstances, the left side is the zero wire, the right side is the live wire, and the upper side is the ground wire. The general installation is specified in this way, with the corresponding zero and live wires of the three hole plug marked opposite to each other (mirror image).
Steps to distinguish ground wire and zero wire using a multimeter:
1. Take out a multimeter, turn the conversion switch of the multimeter to the AC 250V or 500V position, and analyze the specific gear adjustment.
2. Use a red lead to measure the live wire, and a black lead to measure the other two wires. For safety reasons, it is best to use the resistance range of a multimeter to measure the ground wire you measured and the steel bars in your building again. There should be a small resistance (or a path, because the grounding resistance of each building is different, the measured resistance value is also different)
3. When the reading of the multimeter shows a high value, the measured value is the live line. And if one pen holds the metal head with your hand, and one pen touches the three lines, one of them will swing.
4. If the needle does not move and the conversion switch of the multimeter is lowered to the lowest gear one by one, but there is still no obvious reading, then the measured point is the zero line.
5. If there is no grounding, the following methods can also be used: turn the conversion switch of the multimeter to the AC voltage range, connect any probe to the measured point of the power supply, hold the other probe with your index finger and thumb, and if the multimeter has a reading. The measured point is the live line; If the pointer of the multimeter does not move, it is the zero or ground wire.
