How does a digital multimeter distinguish live wire and neutral wire
In fact, as long as we understand the characteristics of the multimeter, we can also easily determine the zero live wire:
The pointer-type multimeter is used as a demonstration. First, select the gear knob switch to the AC500V gear, and lightly press a finger on the metal needle of the black pen (the tighter the finger presses the needle, the higher the reading). The largest reading is the live wire, and the zero wire has no reading. Sometimes there is a potential difference in the measurement, the largest reading is the live wire, the second is the neutral wire, and the smallest is the ground wire.
The second method is to wind the black test lead wire in the left hand for 2-3 turns, of course, the more turns the better the reading will be. Those who are afraid can also touch the black pen to the ground or the wall (the ground and the wall are very dry and the readings are not very obvious).
The multimeter is the most commonly used tool in electrician work. The multimeter can measure voltage, current, resistance, and continuity. Of course, it is very simple to judge the neutral and live wires.
The following electrician's home will use the most commonly used digital multimeter to distinguish the live wire and neutral wire of household electricity:
Use a multimeter to distinguish live wires and neutral wires. We need to insert the black test lead into the common terminal, which is the black hole on the multimeter, and insert the red needle into the red hole. The hole with VAC written on it is the AC voltage file;
To use a multimeter to determine the neutral and live wires, we first need to know the approximate voltage of the line to be tested. For example, the residential electricity is about 220V, so the range we choose is 750V, that is, turn the rotary switch in the middle to 750V;
Then we use the left hand to touch the black pointer to the wall or the ground, hold the red test lead with the right hand, and use the test lead to touch the line to be tested or a live point such as a jack, and we observe the reading of the multimeter;
If the reading of the multimeter is about 220V, then I can confirm that this is the live wire; if the reading of the multimeter is very low, that is, about 20V, then we can confirm that this is the neutral wire;
In the same way, we can also confirm which is the ground wire. If the reading of the multimeter is close to 0, then we can confirm that this is the ground wire;
In this way, we use a multimeter to distinguish the live wire, neutral wire and ground wire in the line, does it feel very simple;
Finally, I suggest that everyone, if you are not a professional electrician, it is best not to operate it yourself. Although it seems simple, there is still danger.
The multimeter has many functions, which is why it is called a multimeter. The multimeter can measure the voltage and current of AC, DC current, resistance, diode, etc. We can all learn and use it in the future. Got it.
