Isolated Mineral-Filled Flexible Fire-Resistant Cable (NG-A / BTLY Series)

Executive Standards
This product is manufactured in strict accordance with stringent enterprise standards and relevant national/international technical specifications:
- Q/320481SS537-2024: Dedicated execution standard for isolated mineral-filled flexible fire-resistant cables.
- GB/T 19666: General rules for flame retardant and fire-resistant wires and cables.
- It also conforms to the highest level CWZ test requirements of the international BS 6387 standard (fire, water spray, mechanical shock).

Model Code Definitions
- NG-A: Isolated fire-resistant cable.
- B: Cable for building wiring (fire-resistant code).
- T: Copper conductor.
- L: Aluminium sheath (serving as isolation layer and earth loop).
- Y: Polyethylene or polyolefin outer sheath (generally low-smoke zero-halogen material).
- WDZAN: Halogen-free low-smoke flame retardant Class A fire-resistant.

Product Specification Range
The conductor uses high-quality annealed copper, with a broad specification design covering power and control requirements:
- Single-core (1 core): 25 – 630 mm²
- Two-core (2 cores): 10 – 240 mm²
- Three-core (3 cores): 2.5 – 240 mm²
- Four-core (4 cores): 1.5 – 240 mm²
- Five-core (5 cores): 1.5 – 185 mm²
- Main combination configurations:
  - (3×6+1×4) to (3×240+1×120) mm²
  - (3×4+2×2.5) to (3×240+2×120) mm²
  - (4×4+1×2.5) to (4×240+1×120) mm²

Core Technical Parameters
1. Rated voltage (U₀/U): 0.6/1 kV.
2. Operating temperature: The maximum continuous permissible conductor operating temperature is 90 °C.
3. Fire resistance performance: Capable of withstanding continuous flame exposure at 950 °C – 1000 °C for not less than 180 minutes, while also possessing resistance to mechanical impact and water spray.
4. Bending radius: The minimum bending radius is typically 10D – 15D (D is the actual overall cable diameter), significantly reducing installation difficulty compared with rigid cables.
5. Electrical performance: The cable has very high insulation resistance stability; its aluminium sheath can serve as 100% earth fault protection.

Cable Structural Characteristics
- High-quality conductor: Uses Class 2 stranded round copper conductor to ensure sound electrical conductivity.
- Fire-resistant layer: High-performance synthetic mica tape is lapped around the conductor.
- Isolation layer (key structure): A sealed aluminium tube structure provides radial water resistance and moisture protection, and acts as an electromagnetic shielding layer.
- Filling material: High-performance mineral compounds (such as magnesium hydroxide) are filled between cores. When heated, they release moisture to reduce temperature and form a hard ceramic protective body.
- Outer sheath: An outer layer of low-smoke zero-halogen flame retardant polyolefin sheath is extruded, offering corrosion resistance, rodent and ant protection, and environmentally friendly characteristics.

Applicable Scenarios
- Top floors and basements of public buildings: Power supply for fire pumps, fire-fighting lifts, and emergency lighting systems.
- Transportation hubs: Underground or enclosed spaces with high fire safety requirements, such as subway stations, tunnels, and airport terminals.
- Industrial production areas: Power circuits requiring high-strength protection in petrochemical, metallurgical, and substation facilities.
- Densely populated places: Large shopping malls, hospitals, schools, theatres, etc.

Product Advantages Summary
1. Very high circuit continuity: Passes fire resistance, water spray, and mechanical shock tests to ensure the power lifeline during fire rescue operations.
2. Efficient installation: The flexible construction allows long-distance continuous delivery without intermediate joints, which not only reduces installation costs but also minimizes potential leakage fault points.
3. Environmentally friendly and energy saving: The outer sheath is halogen-free, produces very low smoke and minimal toxicity during a fire, meeting green building requirements.
4. Corrosion resistance and long service life: The dual protection of the aluminium sheath and low-smoke zero-halogen sheath gives the cable strong ageing resistance and mechanical impact strength.