On the basis of maintaining the safe operation and correct operation of power equipment, we should pay more attention to the quality of equipment and materials as power transmission, especially in summer. Unlike other dangerous things, electricity is invisible and untouchable, but once it is careless, it often pays a huge price of life, Electricity can even be called an electric tiger. In fact, electricity itself is more terrible than a tiger.

Cable aging is a great potential safety hazard. Many fires caused by electricity are mostly caused by cable aging. Therefore, it is very necessary to regularly check whether the cable is aging, but how to check whether the wire is aging still needs some technology. The insulation of our common cables depends on a layer of outer sheath. However, after the cables are used for a long time, they will be oxidized or corroded by the air, and the insulation performance of the cables will become lower and lower. Finally, the cables will age, harden or even fall off. When the cables are aged to this degree, they basically have no insulation capacity, Once the insulation is reduced to a certain extent, it is easy to be broken down in the process of use, resulting in fire, electric shock and other accidents. Understanding the basic knowledge of judging cable aging can eliminate potential safety hazards. Here are some methods and experiences to judge cable aging:

The first way is to check the appearance of the cable along the cable, that is, to observe the insulation layer of the cable. If the cable is hard, the outer layer has cracks, the color is lustrous, darkened, or even falling off, it indicates that the aging problem of the cable has been serious, and it is best to replace it in time to avoid danger.

The second is a more professional and accurate method, which is to use the insulation resistance meter to measure the insulation of electrical lines. The insulation of different lines has different allowable values. For example, the insulation resistance of household 220V line in use shall not be less than 0.22 megohm; The wet value in rainy days shall not be less than 0.1 megohm. If the measured insulation resistance value is less than the above value, there is a problem with the insulation of the electrical circuit. Of course, the service life of the cable is different under different use conditions.