Fire Resistant Mica Glass Fiber Wire

Fire-resistant mica wire solves a different problem than ordinary flame-retardant cable. Flame-retardant insulation is designed to self-extinguish and stop a fire from spreading along the cable run -- but once flame reaches it, the circuit itself dies. Fire-resistant wire is built to keep working through direct flame exposure, maintaining circuit integrity so that fire alarms keep signaling, emergency lighting stays lit, and smoke extraction fans keep running while a building is evacuated. Shanghai Unicorn Cable's GN series achieves this with layers of mica tape -- a naturally fire-resistant mineral -- wrapped directly around the conductor, so the insulation barrier survives even after any polymer jacket around it has burned away. As a direct mica fire resistant cable manufacturer, we test every batch to IEC 60331 and BS 6387 CWZ before it ships.

Choosing between GN500, GN800, and GN1000 comes down to two questions: what voltage does the circuit run at, and how severe is the fire-survival requirement. GN500 (500V, single-layer mica tape, 500°C) covers standard fire alarm and emergency lighting circuits where code compliance is the main driver. GN800 (800V, double-layer mica tape, 550°C) steps up for higher-voltage industrial safety systems where a single mica layer isn't enough insulation margin. GN1000 (1000V, multi-layer mica plus silicone coating, 650°C, verified to survive 950°C direct flame for 3 hours per BS 6387 CWZ) is the specification for nuclear facilities, petrochemical plants, and any installation where failure during a fire is not an acceptable outcome.

Building codes in most jurisdictions mandate fire-resistant wiring for specific circuit types rather than leaving it to designer discretion: fire alarm and detection circuits, emergency and escape-route lighting, voice evacuation and public-address systems, smoke control and stairwell pressurization fans, and sprinkler/fire-pump control wiring typically all require a certified fire-resistant cable, not just a flame-retardant one. Nuclear facilities add IEEE 383 qualification on top of IEC 60331 and BS 6387, and LPCB-listed constructions are available on the GN1000 for insurers and authorities that require third-party certification rather than manufacturer self-declaration.

In practice, the GN series covers a wide span of safety-critical environments -- fire alarm and detection wiring in commercial buildings, emergency lighting circuits in high-rises and hospitals, control and instrumentation cabling in petrochemical plants and steel mills, safety and containment-system wiring in nuclear power stations, and fixed wiring in rail and road tunnels where evacuation systems must keep functioning during a tunnel fire. We manufacture the full GN500/800/1000 range in-house in China with low minimum orders (500 ft per SKU) and sample lengths available for engineering qualification, so specifying engineers can validate fire-survival performance before committing to a production order.