BV Single-Core Rigid Copper PVC Building Wire
BV-450/750V
The 450/750 V rigid copper wire that IEC-aligned projects name on the drawing, in every colour an electrician asks for.
Building Wire & Hook-Up Wire
Building wire is the highest-volume, lowest-margin cable in an export catalogue, and it is where the designation matters most. A 2.5 mm² copper conductor with PVC over it is called
Building wire is the highest-volume, lowest-margin cable in an export catalogue, and it is where the designation matters most. A 2.5 mm² copper conductor with PVC over it is called BV, BVR, H07V-R, THHN or RV depending on which standard the project follows, and each name implies a different voltage class, a different stranding class and a different list of tests. Getting the name right is most of the conversion.
The split is regional and it is sharp. IEC-aligned markets, including most of Asia, the Middle East and Africa on GB/T-based projects, ask for 450/750 V wire to GB/T 5023 or IEC 60227. Markets working to the NEC ask for 600 V THHN/THWN-2 with a UL listing. Voltcore holds UL listing on the building wire line and CCC and CE marking on the rest, and ships both families from the same Yixing plant in 100 m coils or on drums.
5 constructions in Building Wire & Hook-Up Wire
BVR Stranded Flexible Building Wire
BVR-450/750V
The same 450/750 V building wire as BV, with a Class 2 stranded conductor that pulls through conduit without fighting back.
UL THHN / THWN-2 Nylon-Jacketed Building Wire
THHN-THWN2-600V
600 V wire with a nylon jacket over the PVC, UL listed and marked THHN/THWN-2 for NEC projects.
RV Flexible Hook-Up Wire
RV-300/500V
A Class 5 conductor in a thin PVC wall, for anything that gets wired inside a box, a panel or an appliance.
WDZ-BYJ Halogen-Free Building Wire
WDZ-BYJ-450/750V
Cross-linked halogen-free insulation in the 450/750 V building wire sizes, for the buildings where the smoke matters.
BV or BVR: solid or stranded, and why it changes the pull
BV is a rigid conductor: solid Class 1 copper up to 6 mm² and Class 2 stranded above it. BVR is flexible Class 2 stranded throughout. Electrically they are the same size and the same voltage class, so the choice is made on the wall, not on the drawing: a solid conductor holds its shape inside a terminal, and a stranded one pulls through conduit with far less effort.
In practice a large installation uses both. BV goes into the fixed runs that are clipped to a surface or stapled to joists, because it stays where it is put and because the termination under a screw terminal is gas-tight. BVR goes into the conduit sections with more than two bends, and into any run behind a distribution board where the wire has to be gathered and dressed.
- Fixed, clipped or stapled runs: BV, solid conductor
- Conduit with multiple bends and board wiring: BVR, stranded
- Both are 450/750 V to GB/T 5023 and IEC 60227
- Order the colours you will actually need: brown, blue, and green-yellow
THHN and THWN-2: the nylon jacket and the two ratings
A single wire carries both names, and the two describe different duties. THHN is a 90 °C thermoplastic-insulated nylon-jacketed wire for dry locations. THWN-2 is the wet-location version, rated 90 °C in wet and dry locations. The same construction marked THHN/THWN-2 satisfies both, and that is the marking an NEC project will ask to see on the coil.
The nylon jacket is the part that makes it work. It is thin, about 0.10–0.15 mm, but it takes the abrasion of a pull through metal conduit and it resists oil and gasoline to the requirements of UL 83. Underneath it the PVC does the electrical work. Remove the jacket and you no longer have a listed THHN wire, which is the reason a buyer should never accept a PVC-only substitute.
- Ask for the THHN/THWN-2 marking on the wire, not THHN alone
- Sizes are given in AWG or kcmil, not in mm²
- Ampacity is quoted from the 90 °C column of NEC 310.16
- The wire must carry a UL listing mark, not only a UL-style print
When to specify halogen-free wire instead of PVC
The decision is about what the smoke does, not about what the wire does. A PVC-insulated wire burns and gives off hydrogen chloride, which is corrosive to the equipment in the same room and toxic in an enclosed escape route. A halogen-free cross-linked wire burns without the halogen acid, and gives off far less smoke, which is the property that keeps an escape route usable.
That is why the specification changes by building type. In a house or a light commercial unit, PVC wire to GB/T 5023 is correct and economical. In a hospital, a metro station, a data centre or any building with an enclosed escape corridor, the halogen-free wire is what the fire strategy will demand, and the cost of the material is a small part of the total.
- Housing and light commercial: PVC wire, BV or BVR
- Public buildings and escape routes: halogen-free, WDZ-BYJ
- Check the smoke and acidity requirements in the local fire code
- Halogen-free costs more per metre; the reason is the compound, not the copper
Request pricing across Building Wire & Hook-Up Wire
Include cross-section, core count, voltage grade, route length and installation method — those five determine price more than anything else on the page.
- Engineer-reviewed before pricing
- Reference drawings issued with the quotation
- Free sample up to free sample up to 5 m