Black BV 2.5mm² Solid Copper Conductor PVC Wire for Conduit Installation

Cable Designation & Meaning

Construction: Plain copper conductor (solid or stranded), PVC insulation, single-core non-sheathed building wire.

Applicable Standards

• GB/T 5023-2008 / IEC 60227 — Polyvinyl chloride insulated cables of rated voltages up to and including 450/750 V
• GB/T 3956 / IEC 60228 — Conductors (Class 1 solid or Class 2 stranded, copper)
• GB/T 18380 / IEC 60332 — Flame retardant tests
• GB/T 2951 / IEC 60811 — Insulating and sheathing materials — Common test methods

BV-2.5 mm² (black, phase L1) — Copper PVC-Insulated Building Wire Specification & Engineering Data 

1. Product Overview & Rating Summary. BV-2.5 (black) is the standard Chinese copper PVC-insulated building wire rated 450/750 V AC for interior fixed wiring, built and tested per GB/T 5023 / JB/T 8734. Unlike the white variant (neutral/general-purpose), this black carbon-loaded version is the standard phase L1 conductor, designed for industrial switchboard wiring, commercial distribution panels, and motor control circuits. The carbon-loaded black pigment also provides slightly better UV stability than plain white PVC, though the cable remains indoor-rated. Finished diameter is about 3.6 mm, mass about 22 kg/km, supplied in 100 m coils.

2. Layer-by-Layer Construction (Conductor to Outer).

3. Electrical Characteristics. The 2.5 mm² conductor is a solid 1.78 mm annealed copper wire (Class 1, not stranded), giving a maximum DC resistance of 7.41 Ω/km at 20 °C. Routine proof is 2.0 kV AC / 5 minutes. Insulation resistance ≥ 0.011 MΩ·km. With the single core in free air at 30 °C, reference loading is about 24 A; in conduit with three grouped cores, the rating derates to about 19 A. The voltage drop on a 100 m single-phase loop at 24 A is about 3.6 V. Conductor loss at 24 A is about 4.3 W per metre at 70 °C.

Insulation Data

Electrical Parameters

Reference values: 2.5 mm² Cu at 24 A, single-phase 230 V → max load ≈ 5.5 kW. Voltage drop at 24 A ≈ 17.8 V/km per core (≈0.78% per 10 m at 230 V).

Temperature Characteristics

4. Thermal Response & Flame Behaviour. PVC insulation sustains a 70 °C continuous conductor temperature, with short-circuit capability up to 160 °C for ≤ 5 s. The cable is rated for service ambients between 0 °C and +70 °C and must not be installed below 0 °C (PVC becomes brittle). It is flame-retardant to GB/T 18380 / IEC 60332-1 (self-extinguishing). The carbon-loaded black pigment provides marginally better UV stability than plain white PVC, but the cable remains indoor-rated. PVC contains halogen — not halogen-free; for low-smoke halogen-free applications, use WDZ-BYJ.

Fire Performance (BV — Standard)

5. Installation Practice & Handling. Minimum bend radius is 4 × OD (≈ 14 mm) for fixed installation. The solid conductor is rigid and designed for fixed installation only. Install inside conduit, trunking, or switchboard panels — do not leave exposed outdoors. Use standard screw terminals, crimp lugs, or wire nuts — no MC4 connectors needed. Black colour = phase L1; match neutral (blue/white) and protective earth (green/yellow) per local wiring codes. Laying temperature must not fall below 0 °C.

Mechanical & Installation Parameters

6. Typical Service Applications. This black BV-2.5 is the standard phase L1 wire for: switchboard wiring, phase L1 circuits, industrial panel wiring, commercial distribution, motor control circuits, lighting phase wiring. Unlike the white variant (residential socket outlets and neutral circuits), black is chosen where phase conductor colour coding matters — in industrial switchgear, motor control panels, and commercial distribution boards. It is installed inside conduit, trunking, or panel trunking — never outdoors.

7. Testing & Quality Assurance Regime. Routine tests on every coil include conductor DC resistance ≤ 7.41 Ω/km at 20 °C, the 2.0 kV AC / 5 min withstand, dimensional check (insulation ≥ 0.8 mm; OD ≈ 3.6 mm), and visual marking. Type tests include heat ageing (100 °C / 168 h), cold bend at 0 °C, heat shock at 150 °C, flame retardancy per GB/T 18380 / IEC 60332-1, insulation resistance, conductor continuity, and colour check (carbon-loaded black).

The Wire Parameters

The Wire Test Parameters

The Wire Cross Section Structure

Construction Description

8. Company Display

9. Packaging, Storage & Logistics. Standard delivery is 100 m per coil. Each coil carries continuous marking: BV, 2.5 mm², 450/750 V, GB/T 5023, supplier identity, production year, and sequential metre marks. Storage should be in dry, indoor premises at 0 to +40 °C, protected from UV and moisture.

10. Procurement Specification. State "BV-2.5 mm² red, 450/750 V" together with the required length. Always install inside conduit or trunking — never outdoors. For low-smoke halogen-free emergency circuits (e.g. fire alarm systems in public buildings), specify WDZ-BYJ-2.5 red instead. Match red switch/emergency with neutral (blue/white) and green/yellow protective earth per local wiring codes.

11. Cable Industry FAQ.

• Q1: Why use red instead of black for this application? Red is the standard switch control / emergency circuit conductor colour. Black is used for industrial switchboard phase L1. In residential and commercial wiring, red provides instant visual identification of control and emergency circuits during installation and maintenance.
• Q2: What is the difference between red and black BV-2.5? Electrically and mechanically identical — same conductor, same insulation, same voltage rating, same ampacity. The only difference is colour and typical application: red = switch control / emergency / fire alarm; black = industrial switchboard phase L1.
• Q3: Can red BV-2.5 be used for fire alarm circuits? Yes — red is the standard fire alarm circuit colour in many wiring codes. However, for public buildings where low-smoke halogen-free is required, use WDZ-BYJ-2.5 red instead of PVC.
• Q4: What is the difference between red and white BV-2.5? Electrically identical. White = neutral / general-purpose; red = switch control / emergency / phase L1. Choose the colour based on the circuit's role in the wiring system.
• Q5: Can red BV-2.5 be used for emergency lighting? Yes — red is commonly used for emergency lighting circuits. However, emergency lighting circuits often require low-smoke halogen-free cables (WDZ-BYJ) in public buildings.
• Q6: Why use solid copper instead of stranded? Solid copper (Class 1) is cheaper, stiffer, and ideal for fixed installation in conduit and switch boxes. It should not be flexed repeatedly — for flexing applications, use BVR (stranded flexible).
• Q7: Can BV be used outdoors? No — BV is designed for indoor dry locations only. The PVC insulation is not UV-resistant and will degrade when exposed to sunlight.
• Q8: Why is the temperature rating only 70 °C? PVC insulation softens at higher temperatures. For higher temperature rating, use BV-90 or BYJ (XLPE-insulated building wire).
• Q9: What is the maximum circuit current? About 24 A in free air; in conduit with grouped cables, derate to about 19 A. For switch control and emergency circuits, the actual current is typically much lower (below 10 A).
• Q10: Can red BV-2.5 be used for residential phase L1? Yes — in many residential wiring conventions, red is used for phase L1. Check local wiring codes for the required colour convention.
• Q11: What is BVR? BVR is the stranded (flexible) version of BV — same PVC insulation and voltage rating, but uses stranded copper conductor instead of solid. BVR is used where flexibility is needed (e.g. behind switch boxes where wires must bend around terminals).