The core difference between mineral insulated cables and ordinary cables lies in the different insulating materials, which directly determines the significant differences between the two in fire resistance performance, operating temperature, service life and application scenarios.

I. Materials and Structures

Mineral insulated cables are composed of copper conductors, inorganic mineral insulating materials such as magnesium oxide, and copper or steel metal sheaths. All components are inorganic materials, with a relatively simple but compact overall structure. Ordinary cables use organic polymer materials such as polyvinyl chloride and cross-linked polyethylene as insulation and sheaths, with a relatively complex structure, and some materials contain halogen components.

II. Performance Comparison

Fire resistance performance is the most prominent difference between the two. Mineral insulated cables can continuously supply power for more than 3 hours in a flame of 950°C to 1000°C, while the insulation layer of ordinary cables will melt and fail at 300°C to 500°C. In terms of operating temperature, the continuous operating temperature of mineral insulated cables can reach 250°C, and in emergency situations, they can even run close to the melting point of copper, 1083°C, for a short time; the operating temperature of ordinary cables generally does not exceed 90°C. In terms of service life, due to the inorganic material characteristics, the service life of mineral insulated cables can reach 50 to 100 years, far exceeding the usual 20 to 30 years service life of ordinary cables. In terms of environmental protection characteristics, mineral insulated cables produce no smoke, no toxicity and no harmful gases when burning; ordinary cables will release a large amount of smoke and toxic gases when burning, which may become a secondary hazard in fires.

III. Mechanical and Electrical Characteristics

Mineral insulated cables have high mechanical strength, can withstand large external force impacts, and are explosion-proof. The highly compacted insulating material can prevent the propagation of steam, gas and flame. They have a smaller outer diameter and superior waterproof performance. Under the same cross-section, mineral insulated cables can transmit higher current, and their short-circuit fault rating is also better. However, rigid mineral insulated cables are difficult to bend and require special accessories; while flexible mineral insulated cables are relatively easy to install, similar to ordinary cables.

IV. Application Scenarios and Costs

Mineral insulated cables are mainly used in places with extremely high fire safety requirements, such as high-rise building fire protection systems, petrochemical industry, airports, tunnels and data centers. Ordinary cables are suitable for general industrial and civil places. In terms of cost, due to complex materials and processes, the price of mineral insulated cables is usually about 5% to 20% higher than that of ordinary cables. However, due to their long service life and low maintenance cost, their comprehensive cost performance in the whole life cycle is even higher.

Summary: Mineral insulated cables take fire resistance, high temperature resistance, long service life, environmental protection and safety as their core advantages, and are the first choice for high-risk places; ordinary cables are suitable for conventional scenarios with low price and convenient installation. The selection needs to be comprehensively weighed according to the safety requirements of the specific use environment.