The reason why both the live wire and the neutral wire are bright when the test pen is on?
It means that the line is live, that is to say, the line you are measuring is in use. For example, if there is a light in your lighting line, then the test pen will light up the live and neutral lines, or your TV, washing machine, etc. are all on. In use, the test line will also light up at this time. If you turn off all the lights and electrical appliances in your house, and none of the electrical appliances are in use, then you use a test pen to test, the neutral wire will not light up, and only the live wire will light up. There are two situations: 1. , In a one-way circuit, that is, in a loop, if the zero line is on, it means that the zero line has an open circuit; 2. In a three-phase circuit, where the load of each phase is unbalanced or the internal turns and phases are short-circuited and This situation also occurs when the neutral point of the three-phase alternating current is displaced. 3. The zero line heats up to generate a voltage drop. Extended information: Causes and solutions of electrification 1. The neutral line is electrified, which means that there is no good grounding. If it is well grounded, the current will flow into the ground, and the electric pen will not detect it. If the neutral line is detected with an electric pen, either the neutral line is broken or the contact is not good. But this is actually the result, not the reason why the neutral line is charged; 2. Reason: Under normal circumstances, there should be no electricity on the neutral line. Therefore, once there is electricity, it must be a fault; the simplest is electromagnetic induction, and at this time, the zero line is not well grounded, and a loop cannot be formed; secondly, the electrical equipment leaks or the phase line touches the shell, but the current is not large , so it has not tripped; the neutral line is live, and the neutral line must not be well grounded; after the solution is solved, go to the equipment. In the three-phase four-wire power supply system, if the grounding of the neutral line is not good or the grounding terminal is broken, the consequence is that the potential of the neutral line is not equal to 0 when the three-phase load is unbalanced, that is to say, the neutral point is biased. shift. The specific zero line potential is related to the unbalance degree of the three-phase load. The more unbalanced, the greater the neutral point offset and the higher the zero line potential. After the zero line potential is shifted, the phase voltage of the three phases is generally not 220V. Some phases may exceed 220V, while others may be lower than 220V. If the offset of the neutral point is too large, the phase where the phase voltage of the three phases increases may cause the electrical appliance to burn out, and the phase where the phase voltage of the three phases decreases may cause the electrical appliance to fail to work. After the potential of the neutral line rises, when it reaches a certain value, the grounding line will cause an electric shock accident.
