Rated Voltage 0.6/1kV, 1.8/3kV XLPE Insulated Flame‑retardant Power Cable for Coal Mines

Product Purpose and Application Scope

This product is designed for transmitting electrical energy in AC 50Hz power supply and distribution systems, suitable for both underground and surface fixed installations in coal mines. It is specifically engineered for coal mine environments and can operate safely in damp, flammable, and explosive conditions.

Model Naming and Selection

The model naming follows the standard codes for coal mine cables:
- M: Flame-retardant cable for coal mines.
- YJ: Cross-linked polyethylene (XLPE) insulation.
- V: Polyvinyl chloride (PVC) sheath or inner liner.
- Armoring Codes: 2 (Double steel tape), 3 (Fine round steel wire), 4 (Thick round steel wire).
- Outer Sheath Code: 2 (PVC outer sheath).

Common Models and Applications:
- MYJV: XLPE-insulated, PVC sheathed power cable for coal mines. Suitable for indoor, tunnel, and pipe installations where it won't be subjected to significant mechanical force.
- MYJV22: XLPE insulated, steel tape armored, PVC sheathed power cable for coal mines. Suitable for underground, tunnel, and pipe installations; can withstand mechanical pressure but not high tensile force.
- MYJV32: XLPE insulated, fine steel wire armored, PVC sheathed power cable for coal mines. Suitable for underground and vertical installations; can withstand significant mechanical pressure and tensile force.
- MYJV42: XLPE-insulated, thick steel wire armored, PVC sheathed power cable for coal mines. Suitable for environments requiring very high mechanical pressure and tensile strength.

Product Structure

1. Conductor: High-purity oxygen-free round copper wire (annealed copper conductor) complying with GB/T 3956.
2. Insulation Layer: Cross-linked polyethylene (XLPE), offering excellent heat resistance, anti-aging properties, and electrical insulation.
3. Shielding Layer: Soft copper tape (specifically for 1.8/3kV and above voltage ratings).
4. Inner Sheath: PVC compound (for armored models like MYJV22).
5. Armoring Layer: Galvanized steel tape (MYJV22) or galvanized steel wire (MYJV32/42).
6. Outer Sheath: Flame-retardant Polyvinyl Chloride (PVC/ST2), featuring high resistance to wear, oil, acids, and alkalis.

Technical Specifications and Specification Range

- Rated Voltages (U0/U): 0.6/1kV (Max system voltage Um=1.2kV) and 1.8/3kV (Max system voltage Um=3.6kV).
- Specification Range:
  - 3-core: 1.5 to 300 mm²
  - 3+1 core: 4 to 300 mm²
  - 4-core: 4 to 185 mm²
- Voltage Testing:
  - 0.6/1kV: 3.5kV / 5 min without breakdown.
  - 1.8/3kV: 6.5kV / 5 min without breakdown.
- Temperature Ratings: Max long-term working temperature 90°C; short-circuit temperature (max 5s) 250°C.
- Bending Radius: Not less than 15 times the cable's outer diameter.

Flame-retardant Performance

The cable features superior flame retardancy, passing the stringent tests of MT 386.
- Conductors >= 50mm² meet Grade A bundled burning requirements.
- Conductors < 50mm² meet Grade B bundled burning requirements.

Product Advantages

1. Excellent Heat Resistance: The 90°C operating temperature is significantly higher than PVC insulation (70°C), allowing for higher current-carrying capacity.
2. Safety in Explosive Environments: Special flame-retardant materials and structure ensure safe operation in flammable and explosive mine environments.
3. Superior Electrical Properties: XLPE insulation provides higher volume resistivity and lower dielectric loss compared to ordinary polyethylene.
4. Vertical Installation Ready: Its chemical stability and material properties make it ideal for high-drop and vertical shaft installations.
5. Environmental Resistance: The sheath resists coal dust, hydraulic oil, and acidic water, functioning reliably in humidity over 95%.
6. High Mechanical Strength: Armored models like MYJV22 can withstand pressures up to 1000N/cm², protecting against rock squeeze and mine car impacts.

Safety Certification (MA Mark)

This product must obtain the Coal Mine Safety Certificate (MA Mark) before being used in coal mines. It is a mandatory safety requirement by the National Mine Safety Administration for products entering the coal mine market. Procurement processes must verify a valid MA certificate to ensure the cable is safe for underground use.