What are the main construction methods for mineral-insulated fire-resistant cables?
Release date:
2022-08-16 14:17
Source:
Mineral-insulated fire-resistant cable As a type of cable that is heat-resistant, flame-retardant, and fireproof—thanks to its ability to maintain power supply even during a fire—it is widely used in the power lines of critical firefighting equipment. During the engineering installation process, several lessons learned and areas for improvement have been identified. This case aims to summarize the experiences and shortcomings discovered throughout the installation process. So, what are the primary construction methods for mineral-insulated fire-resistant cables?
1. Material Introduction: Mineral-insulated cables, commonly referred to as MI cables, are used for wiring purposes and are often called magnesium oxide cables or fire-resistant cables in China. These cables feature annealed copper conductors, tightly packed magnesium oxide as the insulation material, and an annealed copper sheath. If necessary, an additional plastic sheath can be extruded over the annealed copper sheath. For applications with specific requirements for zero smoke and halogen-free performance, a low-smoke, halogen-free sheath may be added over the outer jacket. Examples include the BTTZ heavy-copper-sheathed mineral-insulated cable, the BTTVZ heavy-copper-sheathed PVC mineral-insulated cable, and the LSF-BTTZ heavy-copper-sheathed low-smoke, halogen-free mineral-insulated cable. This particular type is the BTTVZ heavy-copper-core, copper-sheathed PVC-mineral-insulated cable.
2. Advantages of Mineral-Insulated Fireproof Cables: All materials used in these cables are inorganic, giving them several advantages that other cables simply don’t possess. For instance, they feature excellent fire resistance, high current-carrying capacity, superior mechanical damage resistance, are halogen-free, non-toxic, explosion-proof, waterproof, highly corrosion-resistant, long-lasting, safe to use, capable of handling overloads, resistant to high temperatures, cost-effective, have a small bending radius, and can even deter ants and rodents due to their copper sheath, which also serves as a protective grounding conductor.
3. Introduction to the characteristics of mineral-insulated fire-resistant cables: Since these cables are made entirely of inorganic materials—specifically, metallic copper and magnesium oxide powder—they pose no risk of igniting fires, as they cannot burn or support combustion. Moreover, with copper having a melting point of 1083°C and magnesium oxide reaching an impressive 2800°C, these cables can maintain reliable power supply even when exposed to temperatures close to copper’s melting point. This makes them truly fire-resistant cables capable of delivering uninterrupted power during prolonged fire conditions. Currently, they stand out as the only type of electrical cable that can sustain power for three hours under a 1000-hour fire test, while also enduring the impact of firefighting water jets and heavy objects falling onto them—ensuring safe and reliable electricity supply in hazardous environments.
4. Cable Accessories: Cable accessories include terminals, wiring terminals, grounding pads, and intermediate connector accessories.
5. Construction Tools: The installation tools for mineral-insulated fire-resistant cables mainly consist of two parts: cable-laying tools, and tools for cable connection and termination—specifically, screwdrivers, carpenter’s pliers, a self-made wire-stripping wrench, cutting knives, as well as a liquefied gas torch or jet lighter.
Recommended Articles
Service hotline:
Office phone:+86 0731-22588828 +86 0731-22588886
Address: No. 2999, Donghang Road, Lusong District, Zhuzhou City, Hunan Province, China
San Shen Group QR Code
Shentong Optoelectronics QR Code
Powered by:www.300.cn Changsha