The reason why the zero line and the live line are all bright with an electric pen
It should be that the neutral line is in poor contact somewhere, and the switch does not control the phase line. If the test on the neutral line is bright, the live line is connected through the electrical circuit.
The neutral wire is broken before the place you measure with the electric pen, that is to say, the electricity goes from the live wire, the switch you closed, through the electrical appliance, to the place you measure, because the live wire and the neutral wire have to form a loop with the electrical appliance. Let the appliances work. So, you have to look forward until you find the breakpoint, the other side of the breakpoint is the zero line
Analysis of the reasons why both the neutral and live wires are charged:
1. The neutral wire of the faulty jack has poor contact, it is not broken or poor contact. Originally, the neutral wire has no power, but if the plugboard has a light-emitting tube indicator light, the power of the live wire will come through this indicator light. .
2. Same as above, but there is no indicator light on this plug board, and it shows that the plug board is dotted. This is mostly because the plug board is dirty, for example, it has been soaked in water, and after it dries up, there is no short circuit in the multimeter measurement, and the resistance value is infinite. But even with a resistance of tens of megohms, the 220-volt AC circuit will have several microamperes of current, so this situation is enough to light up the test lead, (especially the digital test lead, which has higher sensitivity) and the misjudgment is zero. Wired with electricity
3. The humidity of the environment and the induction of AC. When the line is wet, although the environment is very dry, the line will also be wet. For example, when the plugboard is taken from a cold room to a heated room, there will be a layer of very fine water droplets on it, which you can't see at all. Because you won't take a magnifying glass to observe such a plugboard carefully. If you are short-sighted, there will be a layer of fog on your glasses as soon as you enter the room, and you will see it immediately and find a cloth to wipe it. At the same time, you will never wipe the insert plate that you brought in with a dry cloth. Again, even though the plugboard is also covered with a layer of water droplets.
In addition, AC can be induced. The correct term should be called electromagnetic radiation. Although it is only 50 Hz, there is also radiation, but the amount of radiation is the same. Sometimes the neon tube of the electric pen lights up because of radiation. The high-voltage line of the old TV, the electric pen The neon tube starts to light up at a distance of 200 mm, because of the high-voltage and high-frequency radiation. Therefore, it is not that the test pen shows that it is charged, so it is really charged.
To sum up: If you want to determine whether the neutral line is really charged or a misjudgment, connect a light bulb to a lamp socket, plug one end into the neutral line hole that is believed to have electricity, and plug the other end into an ordinary neutral line hole. If it is on, the neutral wire is really powered. If it is very weak, it means that the neutral wire with this hole is broken, and there is a soft short circuit between the live wire and the neutral wire hole. The soft short circuit is mostly dirty or oily. Or have been in water. You may say that my plugboard has never been flooded with water, but maybe your wife sprinkled it with water when she passed it here, or she once used this plugboard to plug in the electric cooker to cook, and the rice was cooked. It's overflowing, you just don't know it.
