Single and multi-core wires

The single-core cable wire is a hard wire (BV wire), and only the wires below 10mm2 have a single core. Multi-core cable wire can be divided into multi-core hard wire (BV wire) and multi-core flexible wire (BVR wire).
For example, 2.5mm2 wire, single-core BV wire is composed of 1 strand of conductor with a diameter of 1.78mm; multi-core BV wire is composed of 7 conductors with a diameter of 0.68mm; multi-core BVR wire is composed of 19 conductors with a diameter of 0.41mm Conductor composition.
For home decoration, it is recommended to use single-core BV cable. In addition to being cheap, there are several reasons.

First, the strongest wire in home decoration is the most external force encountered is tension and pressure. In terms of strength, the single-stranded wire is better than others-during the process of pulling and squeezing the multi-core wire, it is easy to break the copper wire, causing a reduction in the current carrying capacity-especially the thin copper wire with a diameter of 0.41mm .
Second, the current-carrying capacity is large in short-distance, low-frequency, low-voltage, and low-current circuits (no need to consider the skin effect). The current-carrying capacity of a single-core wire is larger than that of a multi-core wire.
PS: If the skin effect is considered, the current carrying capacity of the multi-strand wire will be greater-this is also the reason why there is no single-strand wire for wires above 10mm2.
The BV line is a customized product specially launched for decoration. Compared with the BVR line, the BV line has weaker resistance to bending and anti-skin effects. However, due to the simple production process and low price, it is more suitable for home decoration.

Single core cable
In almost all circuits except for decoration and laying, most of them are BVR lines-the adaptability of BV lines is very poor, especially when frequent bending is required, it has a great impact on the life of BV lines, and the difficulty of wiring will also increase. less.
As for the multi-core BV line, it is a product between the single-core BV line and the BVR line-it has a certain anti-skin effect, but the anti-bending ability is still not enough.
Because the single core wire is too hard, the 4mm2 and 6mm2 wall sockets are not easy to connect and are prone to failure. Home improvement generally chooses 4mm2, 6mm2 to choose flexible wire, 2.5mm and 1.5mm to choose hard wire. The above content is for reference only, please refer to the actual situation.