Cable selection

To be honest, I don’t have that great a memory. It’s all just being hyped up over and over again. . But as you said, if it’s just this one issue, then it shouldn’t be a problem. . At worst, you can find some information and tally up the commonly used ones (it’s not a problem to tally them all, right?). Print it out and carry it with you. . After some time, one becomes an expert:P

Well, it should be a good idea.

PVC cables: Names and uses – VV, VLV: power cables with copper (aluminum) cores, PVC insulation, and PVC sheathing; they are used for installation indoors, in tunnels and ducts, or outdoors on supports, and they cannot withstand pressure or mechanical forces. VY, VLY: power cables with copper (aluminum) cores, PVC insulation, and polyethylene sheathing. VV22, VLV22: power cables with copper (aluminum) cores, PVC insulation, steel tape armoring, and PVC sheathing; they are suitable for installation indoors, in tunnels, cable trenches, or buried in soil, and they can withstand pressure as well as other external forces. VV23, VLV23: power cables with copper (aluminum) cores, PVC insulation, steel tape armoring, and polyethylene sheathing

Mnemonic for calculating the current-carrying capacity of wires: The current-carrying capacity of a wire is related to its cross-sectional area, as well as factors such as the material and type of the wire, the method of installation, and the ambient temperature. There are many influencing factors, making the calculation complex. The current-carrying capacity of various wires can usually be found in manuals. But by using a mnemonic along with some simple mental arithmetic, the calculation can be done directly without needing to consult a table. 1. Mnemonic for the relationship between the current-carrying capacity of aluminum-core insulated wires and their cross-sectional area: 5 times for areas below 10, 2 times for areas above 100; for 25 and 35, it’s 4 and 3 times respectively; for 70 and 95, it’s 2.5 times; a 20–30% reduction is applied in cases of conduit use or high temperatures. Add half for bare wire; upgrade for copper wire. 1) The first mnemonic states that the current-carrying capacity (in amperes) of aluminum-core insulated wires can be calculated as a multiple of the cross-sectional area. The Arabic numerals in the mnemonic represent the wire cross-section (in square millimeters), while the Chinese numerals indicate the multiple. The cross-sections of the mnemonics and their multiple relationships are arranged as follows: 1 ~ 10, 16, 25, 35, 50, 70, 95, 120 and above ︸ ︸ ︸ ︸ ︸ five times, four times, three times, two and a half times, two times. 2) The next three lines of the mnemonic deal with changes in conditions. “\"80-90% discount for conduit installation and temperature control\" means that if the wiring is installed using conduits (including installations in troughs or similar structures, i.e., with protective covers around the wires so that they are not exposed), a 20% discount is applied after the calculation is completed ； If the ambient temperature exceeds 25°C, a 10% discount is applied after the calculation. If the cable is installed in conduits and the temperature is still above 25°C, a 20% discount is given followed by another 10% discount; alternatively, a 30% discount can be applied directly. 3) Regarding the current-carrying capacity of bare aluminum wires, the rule of thumb states to \"add half to the value for bare wires\", that is, add half to the calculated value. This means that, compared to aluminum wire with an insulated core, the current-carrying capacity of bare aluminum wire with the same cross-section can be increased by half. 4) Regarding the current-carrying capacity of copper wires, the rule states that \"upgrade the copper wire grade\", which means increasing the cross-sectional area of the copper wire by one level according to the grading system, and then calculating based on the corresponding conditions for aluminum wires.