Fireresistant Cables Safeguard Power in Emergencies

When fire alarms shatter the silence and smoke engulfs everything, what becomes the critical lifeline sustaining survival? The answer lies in three essential systems: emergency lighting that guides escape routes, fire communication systems that relay distress signals, and the robust power supply driving firefighting equipment. All these depend on an electrical lifeline that remains operational in extreme conditions—mineral insulated cables (MICC).

Known alternatively as Pyro cables or MICC (Mineral Insulated Copper Clad cables), these cables feature a unique construction: copper conductors sheathed within a copper casing, with inorganic magnesium oxide powder serving as insulation. This design grants MICC cables exceptional fire resistance, reliability, and electrical safety, making them ideal for high-risk environments like fire alarm systems, emergency lighting, and industrial facilities.

When the sheath material isn't copper, the cables are designated as MIMS (Mineral Insulated Metal Sheathed cables), frequently deployed in corrosive environments, high-temperature applications, or situations requiring non-copper sheathing. Both MICC and MIMS cables maintain the core advantages of mineral insulation, ensuring durability, heat resistance, and electrical reliability under harsh conditions.

During fire emergencies, MICC cables serve as the backbone for maintaining critical circuits—escape lighting, fire sensors, alarm systems, service elevators, water pumps, and smoke exhaust fans. Their continuous operation proves vital for evacuation procedures and firefighting efforts. In stark contrast, traditional plastic cables often fail catastrophically under fire conditions.

While many manufacturers opt for halogen-free polymers like polyethylene (PE) and cross-linked polyethylene (XLPE) due to their cost-effectiveness and ease of processing, these materials carry significant fire risks. Polyethylene possesses high fire load characteristics that facilitate flame spread. More critically, burning polyethylene generates lethal amounts of carbon monoxide. Plastic cables also risk overload when short-circuited or damaged by falling debris, producing toxic smoke and gases. According to NES713 standards, hydrogen chloride (HCL) concentrations reaching 500ppm can prove fatal, while also corroding sensitive computer networks and equipment. Even low-smoke zero-halogen (LSZH) cables demonstrate marginal performance improvements over conventional cables in multiple fire safety studies.

Developed by MICC specialists, mineral insulated fire-resistant cables utilize inorganic materials that eliminate smoke and toxic gas emissions during fires. Their robust mechanical construction withstands impact from falling objects and water spray. In smoke-filled environments, MICC cables significantly enhance evacuation safety, making them particularly suitable for underground structures like road tunnels, parking garages, and utility tunnels. Their installation is strongly recommended—and often mandated by local codes—in transportation hubs, cultural venues, and high-occupancy buildings.

MICC cables comprise three inorganic components: copper conductors, magnesium oxide (MgO) insulation, and copper sheathing. Per IES228 standards, copper elements melt at 1083°C (1981°F), while high-purity MgO withstands temperatures up to 2800°C (5072°F). This enables reliable operation at ambient temperatures reaching 1000°C (1832°F)—a defining advantage over conventional cables. MICC manufacturing employs seamless tubing technology rather than welded tubes, ensuring flawless construction for mission-critical applications. The metallurgical consistency of seamless MICC cables eliminates structural weaknesses and contamination risks associated with welding.

For specialized applications requiring aesthetic coordination (such as architectural integration or event venues), MICC can apply low-smoke and fume (LSF) outer sheathing in custom colors.

MICC cables constitute self-contained systems without polymer components, zinc elements, or conduit requirements. They remain unaffected by conduit-related issues and consistently meet UL2196/ULC-S139 standards for two-hour fire resistance. The UL2196 test represents the world's most rigorous fire cable evaluation, exceeding all other standards with its 1020°C (1868°F) temperature threshold, full-scale vertical/horizontal sampling, and firehose spray simulation.

• Fire detection/alarm networks ensuring early warning
• Emergency lighting circuits maintaining evacuation visibility
• Fire suppression systems powering pumps and sprinklers
• Mission-critical circuits requiring fire endurance

• High-temperature sensors in refineries, steel mills, and glass manufacturing
• Power distribution for heavy industrial equipment
• Control circuits exposed to corrosive or high-vibration conditions

• Offshore platforms and petrochemical plants requiring explosion-proof cabling
• Nuclear facilities needing radiation-resistant wiring
• Power plant backup systems

• Marine vessels with saltwater exposure
• Aerospace systems demanding vibration resistance
• Medical sterilization equipment and imaging devices
• Mining operations in high-humidity conditions
• Renewable energy installations facing weather extremes

• Most MIMS cables operate continuously at 250°C (482°F)

• Withstand 1080°C (1976°F) depending on sheath composition

• Stainless steel or nickel alloy sheaths permit operation beyond 1200°C (2192°F)

• Fire Integrity: Non-combustible construction maintains emergency services without smoke or toxic emissions
• Compact Design: Combined wiring/cable/conduit functionality with smaller diameter than equivalent-current cables
• Flexibility: Fully annealed copper allows complex routing without electrical compromise
• Mechanical Resilience: Resists crushing, twisting, and rodent damage
• Corrosion Resistance: Copper sheathing withstands normal environments; LSF jackets protect against chemical exposure
• Waterproofing: Impermeable metal sheath prevents fluid/gas ingress
• EMI Shielding: Solid copper sheath provides superior electromagnetic compatibility
• Longevity: Inorganic materials prevent degradation, allowing reuse decades after installation

When human safety hangs in the balance, mineral insulated cables provide an uncompromising fire barrier for critical infrastructure systems.