Product Description
Mineral-insulated cable is a remarkable electrical cable renowned for its outstanding performance and reliability.
It is constructed with a solid copper or other suitable metal conductor at the core. This conductor is encased in a compacted layer of magnesium oxide, which functions as a highly efficient insulator. The magnesium oxide insulation not only provides excellent dielectric properties but also contributes to the cable's ability to withstand high voltages and ensure stable electrical transmission.
The outer sheath of the mineral-insulated cable is usually made of a durable metal, such as copper or stainless steel. This metal sheath offers multiple benefits. Firstly, it provides robust protection against mechanical damage, safeguarding the internal conductor and insulation from impacts, abrasions, and other physical stresses. Secondly, it acts as an effective shield against electromagnetic interference, minimizing the impact of external electrical and magnetic fields on the cable's signal integrity.
One of the most significant advantages of mineral-insulated cable is its exceptional resistance to corrosion. It can endure exposure to various corrosive substances and environments, including moisture, acids, and alkalis, without significant degradation of its performance. This corrosion resistance property ensures a long service life and reliable operation in harsh industrial, marine, and other corrosive settings.
Furthermore, the cable exhibits excellent moisture-proof characteristics. It effectively prevents the ingress of water vapor and moisture, maintaining the integrity of the insulation and electrical properties even in humid or wet conditions. This makes it suitable for applications in underground installations, outdoor environments, and areas prone to water seepage.
Another key feature is its overload resistance. Mineral-insulated cable can handle short-term overloading without immediate failure or significant damage. It has the capacity to dissipate heat generated during overload conditions and recover its normal operation once the overload is removed, providing enhanced safety and reliability for electrical systems.
In terms of installation, mineral-insulated cable is relatively flexible considering its robust construction. It can be bent and routed with reasonable ease, allowing for convenient installation in complex building structures and industrial layouts.
Overall, mineral-insulated cable is a top-tier choice for a wide range of applications where high electrical performance, durability, and safety are essential. It is commonly used in critical electrical installations such as power plants, substations, high-rise buildings, hospitals, and data centers, as well as in industrial processes where reliable power transmission and resistance to harsh conditions are of utmost importance.
Product Parameters
1. Conductor
- Material:
- The conductor of mineral - insulated cables is typically made of high - conductivity copper. Copper is preferred due to its excellent electrical conductivity, which ensures efficient power transmission. The purity of the copper used usually meets industry - recognized standards, such as electrolytic - tough - pitch (ETP) copper with a minimum conductivity of 97% IACS (International Annealed Copper Standard).
- Size:
- The cross - sectional area of the conductor can vary widely depending on the specific application requirements. It can range from a few square millimeters (e.g., 1.5 mm² for low - power applications) to several hundred square millimeters (e.g., 400 mm² for high - current industrial applications). The size is precisely specified to meet the desired current - carrying capacity and voltage drop limitations.
2. Insulation
- Material:
- The insulation material is magnesium oxide (MgO). Magnesium oxide is a key component that provides the excellent electrical insulation properties of the cable. It has a high dielectric strength, typically in the range of 10 - 14 MV/m (megavolts per meter), which enables the cable to withstand high voltages without breakdown.
- Thickness:
- The thickness of the magnesium oxide insulation layer is carefully designed to ensure the required insulation performance. It generally ranges from a few millimeters to several millimeters, depending on the cable's voltage rating and other factors. For example, for a medium - voltage cable (e.g., 1 - 10 kV), the insulation thickness might be around 3 - 5 mm.
3. Sheath
- Material:
- The outer sheath of mineral - insulated cables is usually made of metal. Copper and stainless steel are the most common materials. Copper sheaths offer good electrical conductivity and can provide additional shielding against electromagnetic interference. Stainless steel sheaths, on the other hand, are more corrosion - resistant and are suitable for harsh environments such as those with high humidity or chemical exposure.
- Thickness:
- The thickness of the sheath also varies depending on the cable's application and the required mechanical protection. For copper sheaths, the thickness might range from 0.5 - 1.5 mm, while for stainless - steel sheaths, it could be in the range of 0.8 - 2 mm.
4. Voltage Rating
- Mineral - insulated cables are available in a wide range of voltage ratings. They can handle low - voltage applications (e.g., up to 1 kV for lighting and small - power circuits) as well as medium - voltage applications (e.g., up to 35 kV for power distribution in industrial plants and some building applications). The voltage rating is determined by factors such as the insulation thickness, the quality of the insulation material, and the design of the cable structure.
5. Current - Carrying Capacity
- The current - carrying capacity of the cable depends on several factors, including the cross - sectional area of the conductor, the ambient temperature, and the installation conditions. For example, a 4 - mm² copper - conductor mineral - insulated cable might have a current - carrying capacity of around 30 - 40 A (amperes) under normal ambient temperature (e.g., 25°C) and typical installation conditions (e.g., free - air installation). However, this value can change depending on whether the cable is installed in a conduit, in a cable tray, or buried underground.
6. Temperature Rating
- Mineral - insulated cables can operate over a wide temperature range. The typical operating temperature range is from - 50°C to + 250°C. The lower limit of - 50°C indicates good low - temperature performance, making the cable suitable for use in cold environments such as polar regions or high - altitude areas. The upper limit of + 250°C showcases its excellent high - temperature resistance, which is crucial for applications where the cable may be exposed to heat sources such as in industrial furnaces or near high - temperature equipment.
7. Bend Radius
- The minimum bend radius of mineral - insulated cables is an important parameter to consider during installation. It is usually specified as a multiple of the cable diameter. For example, the minimum bend radius might be 6 - 10 times the cable diameter, depending on the cable's size and construction. This ensures that the cable's insulation and other components are not damaged during bending and installation.
8. Length
- Mineral - insulated cables are usually supplied in standard lengths, such as 100 meters per coil or as per customer - specified lengths. The length can have an impact on the overall installation cost and efficiency, as longer lengths may reduce the number of joints and connections, thereby enhancing the reliability of the installation.
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