Each industry has skills and shortcuts for each industry, so in the wire and cable industry, how to remember the problem of cable models is a skill of the industry. Only those who are knowledgeable can remember, and those who don’t understand can learn and understand.
There are many specifications and models of power cables, and they are also very complicated. To be honest, you brought an unusual model, and I don’t know it. Therefore, this article mainly introduces: the composition law of cable specifications. Once you have mastered this law, even if you see something you don’t know, you can know what kind of cable it is and what materials it consists of as long as you find the meaning of the corresponding letter or number.
We often put the specifications and models together. In fact, these two are different categories. You can see from your company’s certificate that the specifications, models, and rated voltages are written separately.
Specification is the main material composition of the cable. Different materials are suitable for use in different places, and different specifications have different uses. Our common cable specifications are VV, YJV, NH-YJV, YJLV, etc. Each letter and number in it has a different meaning.
Common insulating materials are: V (polyvinyl chloride), YJ (cross-linked polyethylene)
Conductor: T (copper, generally omitted and not written), L (aluminum), HL (aluminum alloy)
Common outer sheath materials are: V (polyvinyl chloride), Y (polyethylene)
The armor layer is represented by numbers: 22 (double steel belt wrapping), 32 (thin round steel wire)
Some cables need special properties: NH (fire-resistant), ZR (flame-retardant)
The above is the composition rule of the specification, namely: (special performance)-insulation-conductor-outer sheath-armor layer. For example, NH-YJV is a fire-resistant XLPE insulated PVC sheathed copper core cable; ZR-YJLV is a flame-retardant XLPE insulated PVC sheathed aluminum core cable; WDZ-YJV22 is a low-smoke, halogen-free Type XLPE insulated PVC sheathed copper core cable.
Another category is the intuitive cable model. The cable model indicates the number and size of the neutral wires of the main line. There are 3 grades, 4 grades, 5 grades, 3+1, 3+2, 4+1, etc. 3×4 means three 4mm2 cables; 3×120+1×70 means three 120mm2 main wires and a 70mm2 four-core cable.
There is nothing to elaborate on the model, you just need to remember one point: According to the GB/T standard, the main line of the cable is generally not less than twice the zero line (except for aluminum alloy cables), and only two are special, namely: 35mm2 The main line adds a 16mm2 zero line, and the 150mm2 main line adds a 70mm2 zero line.