IEC Standard XLPE Insulated Low Voltage Power Cable

Executive Standards
This product series strictly complies with the following IEC international standards and their corresponding national adoption standards:
- Core construction standard: IEC 60502-1 (Power cables with extruded insulation and their accessories for rated voltages of 1 kV and 3 kV).
- Conductor standard: IEC 60228 (Conductors of insulated cables).
- Flame retardant performance: IEC 60332-1-2 (Vertical flame test for a single cable) and the IEC 60332-3 series (Vertical flame test for bunched cables).
- Low-smoke zero-halogen characteristics: IEC 61034 (Measurement of smoke density) and IEC 60754 (Determination of halogen acid gas content).
- Fire resistance (fire-resistant types only): IEC 60331 series (Test for circuit integrity under fire conditions).

Model Code Definitions
The product model designation typically follows the international naming system or national industry standard codes:
1. Examples of common international models:
   - N2XY: Copper conductor / XLPE insulation / PVC sheath.
   - N2XH: Copper conductor / XLPE insulation / low-smoke zero-halogen (LSZH) sheath.
   - NA2XH: Aluminium conductor / XLPE insulation / low-smoke zero-halogen (LSZH) sheath.
   - FE180 / PH90: Denotes the fire resistance rating (duration of maintaining circuit continuity under fire).
2. Common code meanings:
   - YJ: Cross-linked polyethylene (XLPE) insulation.
   - V: Polyvinyl chloride (PVC) sheath.
   - Y: Polyethylene or polyolefin sheath.
   - WDZ: Halogen-free low-smoke flame retardant.
   - NH: Fire-resistant property.
   - STA / DSTA: Steel tape armour / double steel tape armour.
   - SWA: Steel wire armour.

Product Specification Range
The conductor may be annealed copper or aluminium, with specification designs accurately covering various load requirements:
- Single-core: 1.5 – 1000 mm²
- Two-core: 1.5 – 400 mm²
- Three-core: 1.5 – 400 mm²
- Four-core: 1.5 – 400 mm²
- Five-core: 1.5 – 400 mm²
- Combination configurations (e.g., 3+1, 3+2, 4+1 cores): 2.5 – 400 mm²

Core Technical Parameters
1. Rated voltage (U₀/U): 0.6/1 kV (maximum system voltage Um is 1.2 kV).
2. Operating temperature:
   - Maximum continuous permissible conductor operating temperature: 90 °C.
   - Maximum conductor temperature during short circuit (max. 5 s): 250 °C.
3. Electrical performance: Power-frequency voltage withstand test is 3.5 kV / 5 min, with no insulation breakdown.
4. Minimum bending radius (D is the overall cable diameter):
   - Single-core non-armoured: ≥ 20D.
   - Multi-core non-armoured: ≥ 15D.
   - Armoured cable: ≥ 12D.
5. Environmental indicators (for low-smoke zero-halogen types): Light transmittance ≥ 60%; pH value ≥ 4.3; conductivity ≤ 10 μS/mm.

Cable Structural Characteristics
- High-quality conductor: Class 1 (solid) or Class 2 (stranded) conductor conforming to IEC 60228. Large cross-sections generally use circular compacted or shaped designs to reduce overall diameter.
- High-performance insulation: XLPE material forms a three-dimensional network structure through a cross-linking process, resulting in thermal ageing resistance and dielectric strength far superior to standard PVC insulation.
- Multi-functional protective layers:
  - Fire-resistant layer (for fire-resistant types): Multiple layers of high-performance mica tape are wrapped around the conductor to maintain circuit integrity under fire.
  - Armour layer (optional): Steel tape or steel wire armour provides strong mechanical protection against external pressure or rodent damage.
  - Specialized sheath: Depending on the environment, flame retardant PVC or low-smoke zero-halogen polyolefin may be selected, featuring good weathering and corrosion resistance.

Core Identification (IEC Standard)
- 1 core: Red or Black.
- 2 cores: Brown, Blue (or Red, Black).
- 3 cores: Brown, Black, Grey (or Brown, Blue, Yellow/Green).
- 4 cores: Brown, Black, Grey, Blue.
- 5 cores: Brown, Black, Grey, Blue, Yellow/Green.

Application Scenario Recommendations
- General industrial and civil use: Indoor, tunnel, cable tray, or conduit installations (recommend types such as YJV / N2XY).
- Direct underground burial: Locations requiring resistance to certain mechanical external forces (recommend types such as YJV22 / N2XY STA).
- High-safety public places: Densely populated areas such as subways, hospitals, and commercial centers (must select low-smoke zero-halogen flame retardant series such as WDZ-YJY / N2XH).
- Fire emergency systems: Critical circuits such as fire pumps and emergency lighting (must select fire-resistant series such as WDZN-YJY / NH-YJV).

Selection and Installation Notes
- Ambient temperature: The ambient temperature during installation should not be lower than 0 °C; otherwise, the cable should be preheated.
- Current-carrying capacity verification: In actual engineering applications, the current-carrying capacity should be corrected based on factors such as ambient temperature and installation density.
- Single-core cable restrictions: For single-core cables used in AC circuits, the armour must be made of non-magnetic material (such as stainless steel tape or aluminium tape), and installation in magnetic conduits is not permitted.