BV, BVR, RV: Both are single core wires.
BV: It is a single-core wire of copper wire, which is relatively hard, also called hard wire.
BVR: It is a single-core wire twisted together with many strands of copper wire, also called a cord.
RV: It is also a soft wire. It is a single-core wire with more strands of copper wire twisted together.
BVVB: It is a hard sheathed wire, that is, two or three BV wires are sheathed together.
RVV: It is a soft sheathed cable, that is, two three or four RV wires are sheathed together.
Generally, household electric wires are easily selected BV or BRV. If it is the storefront decoration, it is recommended to use BVVB sheathed wire.
When purchasing a household wire, you must purchase the wire that meets the national standard. The first thing to look at is whether there is a quality system certificate and whether the certificate is standardized. Also look at its production date and inspection chapter, whether there should be trademarks, specifications, voltages, etc. Then take a wire head and bend it repeatedly. Any soft touch, high elasticity and no crack on the insulator.
Generally, a good quality wire has a specified weight within a certain range. A plastic insulated single-strand copper core wire having a cross-sectional area of 1.5 mm 2 is 1.8 to 1.9 kg per 100 m. The 2.5 mm2 plastic insulated single-strand copper core wire has a weight of 3 to 3.1 kg per 100 m. Finally, look at whether the copper core color is purple, shiny, and soft. Inferior general toughness is poor.