PVC insulated wire includes BV/BVR copper core PVC insulated/flexible wire, NH-BV copper core PVC insulated fire-resistant wire, and WDZ-BYJ/WDZN-BYJ copper core LSZH cross-linked polyolefin insulation/fire-resistant wire. BV is a single-core copper wire, which is hard and inconvenient for construction, but has high strength. BVR is a multi-core copper wire, which is soft and convenient for construction, but has low strength. BV single-core copper wire - generally for fixed places, BVR wire is a copper-core PVC insulated flexible wire, which is used in the occasions where the fixed wiring requires softness, and is generally used in occasions where there is slight movement. In addition, the current carrying capacity of the BVR multi-strand line is larger than that of the single-strand line, and the price is also higher. Usually, BVR can be used for the cables inside the cabinet, without such a large strength, which is convenient for wiring.BV/BVR wires are the most used household wires. Taking a new house of 100 square meters as an example, the copper core BV wire of 4mm² square millimeters is 200 meters, 400 meters for 2.5 mm², 300 meters for 1.5 mm², and 100 meters for 1.5 mm² of copper core BV two-color wire. The above is not the ceiling decoration, if you want to have a ceiling, the line of 1.5 mm² should be more.