Rigid Copper Sheathed Magnesium Oxide Mineral Insulated Cable

Rigid Copper-Sheathed Magnesium-Oxide Mineral-Insulated Cable (MI Cable)

Rigid Copper Sheathed Mineral Insulated Cable (also called copper-sheathed MI cable or MICC) is a high-integrity electrical cable in which copper conductors are embedded in compacted magnesium-oxide (MgO) powder and enclosed within a seamless copper sheath. As a type of Mineral Insulated Cable, it offers exceptional fire survivability, mechanical protection, and long-term stability — making it the preferred choice for mission-critical power, control, and instrumentation circuits.

Description

Copper sheathed mineral magnesium oxide insulated fireproof cable is an inorganic cable composed of high conductivity copper as conductor, electrical magnesium oxide powder insulation, and oxygen-free dephosphorized copper tube sheath.

The particularity of its structure makes it far superior to ordinary plastic and rubber plastic cables in many aspects such as electrical properties, mechanical properties, fire and explosion resistance, and environmental protection performance.Therefore, copper sheathed mineral magnesium oxide insulated fireproof cable is internationally recognized as the safest and most reliable fireproof cable. 

At present, copper sheathed mineral magnesium oxide insulated fireproof cable has been widely used in steel metallurgy, petrochemical industry, construction machinery, electronic communications, glass pharmaceuticals, ships and offshore platforms, important military facilities, etc.

Why choose Tongda’s Rigid Copper-Sheathed MI Cable?

• Passive fire protection — inorganic MgO insulation remains stable at extreme temperatures, preserving circuit integrity in fires

• Robust mechanical & moisture protection — seamless copper sheath resists abrasion, corrosion and EMI while providing physical shielding. 

• Long service life — no organic insulating materials to age or combust; suitable for high-temperature and hazardous environments. 

• Project readiness — produced to rigid manufacturing tolerances for predictable electrical performance and simple, reliable terminations. 

Typical applications

• Fire alarm & fire-pump circuits, emergency lighting and life-safety systems. 

• Power and instrumentation in power stations, subways, airports and tunnels.

• Petrochemical, oil & gas and other hazardous-area installations requiring circuit integrity. 

• Nuclear and radiation-exposed instrumentation where inorganic insulation is required. 

Key technical Specification

Values below are representative — for final selection please request the product datasheet or contact our technical team for project-specific ratings.

Project case highlights

• Metro Tunnel — Emergency Lighting Circuits

Supplied rigid copper-sheathed MI cable for emergency lighting and control circuits in a 3-station metro tunnel refurbishment. Cable selection prioritized circuit integrity under fire and moisture-resistance in underground conditions. (Project scope: 5,000 m). 

• Power Plant — Control & Instrumentation Loops

Delivered multi-core rigid MI cable for turbine instrumentation and control lines where elevated temperatures and EMI shielding were critical. 

• Data Centre — Fire-Survivable Distribution

Supplied single-core copper-sheathed MI cable for emergency backup power feeders and fire alarm loops to ensure uptime during thermal events. Supplied technical guidance for terminations. 

Ready to specify Rigid Copper-Sheathed MI Cable for your project?

Request a technical datasheet, sample or project quotation now — click Get a Quote or email with your project details (cable type, conductor size, cores, length, required standards). Fast technical reply within three business day.