How to distinguish neutral wire, live wire and ground wire with multimeter
I think there are several ways:
1. Turn the multimeter to the maximum range of AC voltage, hold the needle of one stylus with one hand, and connect the other stylus to the wire you want to measure. The high voltage is the live line and the low voltage is the zero line.
Judging by this method, the voltage of the fire line varies from tens to 100 volts. But the actual voltage is normal, because the human body+shoes have resistance, so the measured voltage will be low. How much is related to shoes and grounding resistance.
Note: you must ensure that the voltage gear is used. If you use resistance or current gear, you will get an electric shock! ! !
2. The multimeter is set to the AC voltage range of 750V or 250V, and one probe is connected to the ground wire or the shell of the power distribution cabinet (the shell of the power distribution cabinet is generally grounded), and the other probe is connected to the measured wire. The live wire measures a voltage of about 220V; The voltage measured by the zero line is very low, close to zero.
In the practical application of electrician, this method is generally used to measure the voltage of each phase of distribution cabinet, and the results measured by this method are accurate and reliable.
3. The multimeter is set to the AC voltage range of 750V or 250V. Wrap the thread of a watch pen around your finger several times, and the watch hand hangs without touching anything; The other probe touches the wire to be measured. If the multimeter shows that there is a certain voltage as the live wire, it is not shown as the zero line. This method is not very reliable, and sometimes there are misjudgments.
Extended data
Multimeter, also known as multi-meter, multi-meter, three-meter, multi-meter, etc., is an indispensable measuring instrument in power electronics and other departments, and its main purpose is to measure voltage, current and resistance. Multimeters are divided into pointer multimeter and digital multimeter according to the display mode. It is a multifunctional and multi-range measuring instrument. Generally, the multimeter can measure DC current, DC voltage, AC current, AC voltage, resistance and audio level, and some can also measure AC current, capacitance, inductance and some parameters of semiconductors (such as β).
