Understanding Standard Prefixes for Electric Wires and Cables
1. Overview
The standard prefixes for electric wires and cables are defined according to national standards (GB/T series) or industry regulations. They classify cables based on key functional attributes such as:
- Safety performance (e.g., WDZ—halogen-free, low-smoke, flame-retardant; NH—fire-resistant)
- Environmental adaptability (e.g., MC—mineral-insulated; -22—steel tape armored)
- Usage and structure (e.g., K—control cable; RVVP—shielded flexible wire)
- Base material (e.g., T—copper conductor; Y—cross-linked polyethylene insulation)
These prefixes provide an intuitive way to identify critical cable characteristics, ensuring proper selection for different applications (residential, industrial, fire protection, etc.).
2. Prefix Logic and Interpretation
Prefix letters follow a specific combination logic (e.g., "Safety → Environment → Usage → Material"). Each letter corresponds to a distinct function (e.g., W—halogen-free, Z—flame-retardant, N—fire-resistant, Y—polyethylene). By decoding a cable model (e.g., WDZN-KVV22, WDZN-YJV), users can quickly understand its safety rating, environmental suitability, and purpose, avoiding selection errors.
A. Detailed Classification of Standard Prefixes
1. Safety Performance (Fire Protection, Environmental Safety, Flame Retardancy – GB/T 19666, etc.)
These prefixes indicate critical safety levels related to fire hazards, toxic gas emissions, etc. They are widely used in densely populated areas (homes, malls, hospitals) and fire protection circuits.
| Prefix | Meaning | Key Features (Per National Standards) | Typical Applications |
|---|---|---|---|
| WDZ- | Halogen-free (W), Low-smoke (D), Flame-retardant (Z) | 1. Halogen-free: No release of halogenated gases (e.g., chlorine) when burning; 2. Low-smoke: Minimal smoke density for visibility during fires; 3. Flame-retardant: Prevents flame spread (meets GB/T 18380 flame retardancy levels). | Residential sockets/lighting, mall power distribution, hospital wards |
| WDZN- | Halogen-free, Low-smoke, Flame-retardant, Fire-resistant (N) | Adds fire resistance to WDZ: Maintains power supply for ≥90 minutes at 750–800°C (per GB/T 19666), ensuring emergency circuit reliability. | Fire emergency lighting, fire pumps, elevator recall circuits |
| ZR- | Flame-retardant (halogenated, traditional) | Uses halogenated materials (e.g., PVC) for flame retardancy; releases small amounts of halogen gas when burning. Lower cost than WDZ but meets GB/T 18380 flame retardancy standards. | Warehouses, temporary buildings |
| NH- | Fire-resistant (halogenated, traditional) | Halogenated material + fire-resistant layer; maintains power during fires but releases halogen gas. Lower environmental safety than WDZN. | Older buildings’ fire circuits, industrial emergency power |
2. Environmental Adaptability (Temperature, Corrosion, Mechanical Resistance – GB/T 2951, etc.)
These prefixes address extreme conditions (high/low temperatures, corrosion, mechanical stress) in industrial (chemical, metallurgical), outdoor, or underwater applications.
| Prefix | Meaning | Key Features | Typical Applications |
|---|---|---|---|
| MC- | Mineral-insulated | 1. Copper sheath + magnesium oxide insulation; withstands high temps (250°C long-term, 1000°C+ short-term); 2. Fireproof/explosion-proof; 3. Resists corrosion (acids/alkalis). | Chemical plants, metallurgical furnaces, underground pipelines |
| HF- | Oil-resistant | Uses nitrile rubber or oil-resistant PVC; resists mineral oil/lubricant immersion (per GB/T 2951). | Machine tools, automotive wiring, oilfield pipelines |
| CY- | Marine reinforced | Enhanced saltwater/corrosion resistance (GB/T 9331) + flame retardancy; withstands wave impact. | Ship decks, engine rooms, offshore platforms |
| -22 | Steel tape armored (structural suffix) | Outer layer: galvanized steel tape (GB/T 2952); resists crushing/impact for direct burial. | Outdoor buried cables, underground garages |
| F46- | Perfluoroethylene-propylene insulation | Fluoroplastic material: -200°C to 200°C; resists strong acids/alkalis/oxidizers (GB/T 11016). | Labs, chemical reactors, cold storage |
3. Usage & Structure (Matching Specific Devices/Scenarios – GB/T 5023, GB/T 12706, etc.)
These prefixes define the cable’s purpose or physical structure, crucial for residential, industrial control, and precision equipment applications.
| Prefix | Meaning | Key Features | Typical Applications |
|---|---|---|---|
| BYJ- | Cross-linked polyethylene wiring cable | 1. Insulation: XLPE (90°C, higher than traditional BV’s 70°C, GB/T 5023); 2. Eco-friendly: Halogen-free, low-smoke. | Home sockets, lighting circuits |
| K- | Control cable | Multi-core thin conductors (flexible); for industrial signal control (GB/T 9330). | Factory production lines, substation control circuits |
| RVVP- | Shielded flexible wire | 1. Soft structure (fine stranded copper); 2. EMI shielding (GB/T 5023); 3. Combines power + signal transmission. | Surveillance cameras, audio systems, smart sensors |
| YH- | Welding machine cable | 1. High-current: Thick stranded copper for welding currents (GB/T 5013); 2. Weather-resistant. | Welding machines, arc welders |
| DJ- | Computer cable | Low capacitance/attenuation (GB/T 18215); high-speed signal transmission. | Data centers, precision instruments |
4. Base Material (Conductor, Insulation – GB/T 3956, etc.)
These prefixes indicate fundamental properties (conductivity, temperature resistance).
| Prefix | Meaning | Key Features | Typical Applications |
|---|---|---|---|
| T- | Copper conductor (default if omitted) | High conductivity (resistivity ≤0.0172Ω·mm²/m, GB/T 3956). | Most residential/industrial cables (e.g., BV, YJV) |
| L- | Aluminum conductor | Cheaper than copper; ~60% conductivity (GB/T 3956); lightweight. | High-voltage overhead lines, rural grids |
| Y- | Cross-linked polyethylene insulation | Heat-resistant (90–125°C), stable insulation (GB/T 12706). | High-voltage cables (YJV), residential BYJ wires |
| V- | PVC insulation/jacket | Heat-resistant (70–90°C), low-cost (GB/T 5023); releases HCl when burning. | Traditional BV wires, RVV cables |
5. Prefix Decoding Guide (GB/T Logic)
Decode cable models in this order: Safety → Environment → Usage → Material.
Example:
- WDZN-KVV22 = Halogen-free, low-smoke, flame-retardant, fire-resistant (WDZN) + Control cable (K) + PVC insulation/jacket (VV) + Steel tape armored (-22).
→ Suitable for fire control rooms and underground burial.
B. Core Prefixes Explained (e.g., WDZ-)
1. WDZ-: Halogen-Free, Low-Smoke, Flame-Retardant
A key prefix for high-safety applications (hospitals, subways):
| Letter | Meaning | Purpose |
|---|---|---|
| W | Halogen-free | Prevents toxic gas (e.g., chlorine) release during fires. |
| D | Low-smoke | Minimizes smoke (≥60% light transmittance) for evacuation/rescue. |
| Z | Flame-retardant | Stops flame spread (ZA/ZB/ZC grades: ≤5m/10m/15m burn length). |
Full meaning: WDZ-XX = Halogen-free, low-smoke, flame-retardant XX cable (e.g., WDZ-YJV).
2. Common Prefix Letters (Functional Categories)
1. Base Insulation/Jacket Materials
| Letter | Meaning | Example |
|---|---|---|
| Y | Polyethylene | YJV (XLPE insulation) |
| V | PVC | VV (PVC insulation + jacket) |
| R | Soft structure | RV (flexible PVC wire) |
2. Special Performance
| Letter | Meaning | Example |
|---|---|---|
| Z | Flame-retardant | WDZ, ZR (halogenated) |
| N | Fire-resistant | NH-YJV |
| P | Shielded | BVVP (EMI-resistant) |
3. Installation Environment/Structure
| Letter | Meaning | Example |
|---|---|---|
| C | Marine | CJV (shipboard cable) |
| Q | Light-duty | YQ (portable tools) |
| J | XLPE | YJV (general wiring) |
3. Example: Cable Model Decoding
- BV: B (wiring) + V (PVC insulation) + Copper (default) → PVC-insulated copper wire (residential sockets).
- WDZN-YJV: W (halogen-free) + D (low-smoke) + Z (flame-retardant) + N (fire-resistant) + YJV (XLPE insulation) → Fire-safe cable for hospitals/subways.
- RVV: R (soft) + VV (PVC insulation/jacket) → Flexible power/signal cable (appliances, CCTV).
Conclusion: Cable prefixes are "feature codes." Understanding them ensures correct selection (e.g., high-temp → "F," fire zones → "NH," homes → "WDZ-BYJ").
