Method and steps for measuring three-phase electricity with a multimeter
1. We know that household 220V AC is very dangerous, as long as it does not touch the wire directly, it is not dangerous. Similarly, direct contact with 380V industrial electricity is also very dangerous. Its frequency of 50HZ and high voltage of 380V are more harmful to the human body. So you must know its characteristics and key points of use.
It is important not to touch any wires and metal parts with bare hands at any time. Because the three wires of the 380V power supply are all live wires, touching any of them can form a dangerous electric shock voltage of 220V with the earth. So pay special attention to the safe use of electricity. First of all, confirm that the multimeter pen is in good contact, and turn the multimeter range switch to the AC position.
2. First of all, make sure that the pens of the multimeter are in good contact, and turn the range switch of the multimeter to the AC position. According to the principle of using the multimeter from high-end to low-end, it is estimated that there is no 1KV power supply to be tested, so choose 500V.
3. For the safety of operation, people can stand on dry boards or wooden benches. In this way, the human body and the earth are insulated. If you are in a wooden building, it is not dangerous to touch a live wire, but at this time you are an extension of this wire, and you cannot touch anything else, the wire or the earth. If the contact constitutes a circuit, it is dangerous. Now bring the multimeter close to the power source i.e. the contactor. The two test leads of the multimeter are in contact with the two metal parts of the contactor, and there is no distinction between red and black test leads, or U, V, and W. Just two lines.
4. At this time, you can see from the panel of the multimeter that the pointer deflects to the right, and it will not move when it reaches a position. This value is the voltage value between these two lines. The reading is seen in this way. The left end of the second arc on the panel of the multimeter has the sign V, indicating that it is voltage. Voltage is divided into AC and DC, that is, wavy lines and straight lines. We measure alternating current. The values are on this arc.
Since we are using 500 gears, the scale is 10, 50, 250, and each gear is calculated by 5 times. Our 500 is 10 times more than 50, and we can just see the scale line of 50, which is just at the value of 38, so 10 times more is 380V. The same is true for other gears, you can read and read the value.
5. Then keep one test pen in the same position, and the other pen connects to the third line. It can also be UV, UW, VW.
6. The measured results are all 380V. The characteristic of this three-phase electricity is that the voltage between every two lines is 380V, which is also the line voltage of 380V. This is the three-phase three-wire power supply mode. There is also a three-phase four-wire system, which has a neutral wire, and their relationship is 380V between the live wires, and 220V between the neutral wires.
7. In this way, you have learned how to read the value on the multimeter, and also know some characteristics of three-phase electricity.
