Household wires corroded
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This post was last edited by snifflily on 2010-6-1 16:42 I renovated my house, and the electrician came to connect the wires (that is, twist the live wire and neutral wire together in the switch box), but he did not wrap insulating tape around the parallel wires. I didn't pay attention. After the putty was put on the house three weeks later, I found that the putty had stuck to the copper core wires. The wires were seriously blackened. I tested the resistance and found that it was 0.4 ohms. Some places where there is no putty are also oxidized. I don’t know if it’s my psychology or if the corrosion is serious. At present, I just spread out the wiring and polished it with sand. After reconnecting, the resistance is almost 0, but the smoothness and brightness are far from the state of the new wiring. I don't know if the power consumption will increase in the future. Because I have putty it on and don’t want to rewire it, my question now is whether this situation will affect the safe use of electricity? If so, is there a good way to deal with it? (You don’t have to throw eggs, since you’re already feeling depressed).
I don’t know if it can be avoided by using solder to connect it. I haven’t encountered it before. You can try it.
Where does your 0.4 ohm come from? If you test it with a multimeter, it can be ignored, because this coefficient has exceeded your data for the insulation of the line itself. There should be no problem. Here is a method for you. If you are worried, you can use a knife to connect the wire. Scrape off the fresh copper inside and then put the wires together and solder them with a soldering iron. This way there will be absolutely no problem. If you don't care very much, just wrap the joints with PVC self-adhesive tape, because for the sake of electrical safety, you must wrap them regardless of whether you get an electric shock or not.
This post was last edited by snifflily on 2010-6-1 18:01. Reply 3# Thank you for your help. As mentioned before, I have scraped the copper wire with sandpaper and a blade. The current measurement is close to 0 ohms, but I am afraid it will increase in the future. In addition, I am worried that the large current after loading will cause local high temperatures here, which may cause potential hazards. I bought a new wire. If there is resistance, it should be mainly caused by the connector. The 0.4 ohm is measured by shorting one end at the place where the terminal needs to be connected. There is such a damaged connector in the middle. The line current of a 2000W induction cooker is 10 amps, so there is 40W of power here. Wouldn’t it be scary to think about it? I can insulate it with insulating tape, and since it is in the junction box, I don't have to worry about the insulation without load. What I'm worried about is that the high temperature will cause insulation failure after carrying a large load, which will lead to safety accidents such as fires. That's a big deal.
High-power household electrical appliances generally use a separate cable, such as air conditioners. There should be no connectors in the middle and there should be no public issues. Lighting and low-power sockets are shared and should be reasonably distributed according to the area. The decoration company we found just needs to put forward the requirements and supervise it in place.
Reply 4# snifflily Let me give you an analogy. Generally speaking, the power distribution box at home distributes air conditioners and power lines in the kitchen and bathroom with more than 4 square meters. Most of them are 6 square meters. Most ordinary sockets are 4 square meters. Even in old houses (houses after 1998), the sockets are not less than 2 .5 square meters, this is a conservative statement. There is absolutely no problem with a current carrying capacity of 1.5 square meters of 19A for a long time. There is absolutely no problem with a current carrying capacity of 2.5 square meters of 30A for a long time. Let me calculate the load of your home for you. Current household electricity meters are generally 5-40A, that is, 40* 220V = 8800W allows instant overload, which means that the possibility of ordinary household electricity reaching 10KW at the same time is very small. This is a bit far-fetched. Let’s get back to the subject. The error of our multimeter’s pen is also very large, so the resistance you tested can be completely ignored. If you look at the lighting circuit, socket circuit and air conditioning circuit, the voltage drop and line voltage drop caused by the mixed resistance are allowed. The contact surface of the switch and the contact surface of the socket are not without resistance. You can test it with a multimeter. You insert a plug into the socket and test the resistance between the socket and the plug. The resistance is not small, so there is no need to care about the resistance. Micro boilers are not the most powerful electrical equipment in the home. The largest electrical equipment should be air conditioners and water heaters.
Reply 6# Thank you very much. When you say that, I feel a lot more at ease, so as not to make myself feel knotty. But I can't give you any extra points. You are welcome to come to the mechanical technology area to communicate.
Reply 7# snifflily Welcome to visit us often. We are separated by mountains and rivers. Hehe, I am not a professional in the mechanical part, so I will go there often.
Insulated copper wires are generally damaged at the joints. If the ends are taken care of, the problem is not big. Crimping should be used as much as possible after copper wire joints. For example, connecting terminals, or tin-enamelling after winding can also prevent oxidation. If a large current is passed through for a long time, the joints are most likely to heat up, and over time, the joints will be burned out.
Just re-wrap the insulation.
That's wrong. The live and neutral wires are not wound together. The paint is a little corroded. Just reconnect them.