There are only two types of household electrical wires: flexible wires and BV wires. Flexible cords are also called sheathed cords. It is usually made of multiple strands of fine copper wire twisted and has a soft texture. Hence, it is called flexible wire. It is usually denoted by the symbol BVR. The full name is copper core PVC insulated flexible wire. B means the material is copper; V means PVC insulating layer; R is the first letter of Ruan in Chinese Pinyin, which means flexible wire.

BV wire is also known as plastic copper wire. Usually a single copper wire with a hard texture. Therefore, it is called the BV line and is denoted by the symbol bv. Its full name is copper core PVC insulated wire. Each letter represents the same meaning as the jumper, but without the R.

So, what is the main difference between a soft line and a BV line? Which current-carrying capacity (i.e. allowable current) is greater if the cross-sectional area is the same?

The main difference between a cord and a BV cord is not only a cord and a BV cord , but also the price: the price of the soft wire of the same thickness is higher than that of the BV wire.

In addition, for flexible wires and BV wires of the same thickness, the allowable current of the flexible wire is larger than that of the BV wire, that is, the current carrying capacity is higher. big. Since the flexible wire has a larger surface area under the condition of the same thickness, the current carrying capacity of the flexible wire is larger. When working in an AC line, the current gradually flows on the surface of the conductor as the frequency increases, so there is no current in the middle conductor. The higher the current frequency, the more pronounced this effect is.

However, the frequency of household appliances in our country is 50Hz, which is low frequency, and the skin effect is not obvious. The current carrying capacity of the BV wire is almost small. Although there are fewer BV wires, BV wires have better firmness, better wiring effect, more beautiful, stronger and less loose:

Therefore, families use hard wire as the main line. Also, it's cheap. The electricity consumption of individual households is not that large. In general, thick and thin lines can meet the requirements. There is no need to choose a flexible cord with high ampacity. If the circuit moves a lot, then the flexible wire is better than the rigid wire, and its toughness is also better than the rigid wire. Therefore, how to choose the wire can be determined according to the actual situation.

The vast majority of wire and cable products are elongated products with exactly the same error), which is determined by the characteristics of the system or device used as a line or coil. Therefore, to study and analyze the structural composition of cable products, we only need to observe and analyze its cross-section.

The structural elements of wire and cable products can be divided into four main structural elements: conductors, insulating layers, shielding and protective layers, and Filling elements and tensile elements. According to the use requirements and applications of the product, some products have very simple structures.