NG-A cable, with the full name NG-A(BTLY) isolated flexible mineral-insulated fire-resistant cable, is a high-performance fire-resistant cable upgraded from the traditional BTTZ rigid mineral-insulated cable. It uses an aluminum sheath instead of a copper sheath, combining excellent fire resistance, flexibility, and cost-effectiveness, and is widely used in building and industrial scenarios with extremely high safety requirements.
I. Core Structure and Material Characteristics
The NG-A cable adopts a multi-layer structural design from inside to outside to ensure stable operation in extreme environments:
Conductor: High-purity oxygen-free copper stranded wire is used, offering excellent electrical conductivity and a higher current-carrying capacity than ordinary cables of the same specification.
Insulation layer: Phlogopite mica tape wrapping is used, with temperature resistance up to above 800°C, and no carbon particles are produced, enhancing electrical stability.
Metal sheath: Aluminum alloy sheath provides good mechanical protection and grounding function, while being lower in cost and lighter in weight than a copper sheath.
Isolation sheath and fire-resistant layer: Covered with cross-linked polyethylene or low-smoke halogen-free material, with inorganic fire-retardant materials such as Mg(OH)₂ or Al(OH)₃ added, which expand at high temperatures to resist flame.
Outer sheath: Made of polyolefin or polyvinyl chloride material, featuring water resistance, rodent and termite resistance, and corrosion resistance.
II. Outstanding Performance Advantages
Excellent fire resistance
Passes three stringent BS6387 tests:
Continuous power supply for 180 minutes under a 950°C flame without breakdown;
Withstands 15 minutes of water spray without breakdown after 30 minutes of burning under a 650°C flame;
Withstands 15 minutes of impact and vibration without damage under a 950°C flame.
Can maintain circuit continuity for more than 3 hours in a fire, ensuring the normal operation of fire-fighting equipment.
Convenient installation, one-piece without joints
Adopts a continuous metal sheath forming process, can be customized in length as needed, and is delivered in complete coils, avoiding safety hazards caused by intermediate joints;
Small bending radius (≥12D), no need for conduit laying, and high construction efficiency.
Safe and environmentally friendly
Halogen-free and low-smoke throughout, releasing no toxic gases when burning, with light transmittance exceeding 80%, far higher than the standard 60%;
Suitable for hospitals, subways, shopping malls, and other densely populated places, enhancing escape safety.
High mechanical strength and protective capability
The aluminum sheath is sturdy and durable, resistant to compression, tension, and rodents and termites, and the cable can still work normally even when deformed by one-third;
Excellent waterproof performance, capable of long-term operation under water immersion.
Energy-saving and long-life
Low operating temperature (90°C long-term), low line loss, and current-carrying capacity 7%-10% higher than YJV cables of the same cross-section;
The inorganic material structure has a service life of more than 30 years, suitable for long-term operation projects such as nuclear power and energy.
III. Typical Application Scenarios
Due to its high safety and reliability, NG-A cable is widely used in the following key locations:
High-rise buildings: Fire water pumps, emergency elevators, smoke control and exhaust systems, emergency lighting, and other fire-fighting power supply lines;
Transportation hubs: Power and control lines in enclosed spaces such as airport terminals, subway tunnels, and stations;
Industrial high-risk areas: Connection lines in metallurgical high-temperature workshops, chemical flammable and explosive areas, and nuclear power plant containment;
Public facilities: Hospitals, museums, data centers, large shopping malls, and other places with high requirements for power supply continuity;
Ancient buildings and cultural relic protection units: Concealed installation does not affect appearance, and is smoke-free and non-toxic, avoiding secondary fire damage.
