The difference between BLX cable and overhead insulated cable
At present, the amount of overhead cables in China is increasing. All enterprises are producing various overhead cables needed by the development market. In daily sales and production, some customers still propose to order BLX cables, replace overhead insulation. According to the market survey, the domestic mainstream wire and cable manufacturers are no longer producing BLX cables, so the author puts forward some humble opinions on the differences between the two cables: 1. At present, domestic enterprises producing low-voltage overhead cables all use the national standard GB/T 12527- 2008 'rated voltage 1kV and below overhead insulated cables' as the basis. This standard is the latest National Standard Revised and updated in 2008. Overhead insulated cable is mainly used for overhead fixed laying, home wire and other places, and its insulation material adopts weather-resistant special overhead insulated cable material, therefore, overhead insulated cables have the advantages of simple structure, safety and reliability, excellent mechanical and physical properties and electrical properties, environmental resistance and ultraviolet resistance, etc. Because their insulation adopts weather-resistant special overhead insulated cable materials, the long-term allowable working temperature of the cable is as high as 70℃ or 90℃, and the electrical insulation performance is excellent, with the volume resistance reaching 1. Above 0 × 1012 Ω m; In the laying, the use of overhead insulated cables can reduce the laying gap, save the line corridor and reduce the voltage drop; In use, it can reduce the occurrence of power supply accidents and ensure personal safety. 2. At present, domestic enterprises produce BLX cables, mainly based on JB/T1601- 1993 'Rubber insulated fixed laying wires with rated voltage of 300/500 V', this standard is formulated and released by 1993 and has not been updated in the past 20 years, this product has gradually been replaced by overhead cables in the market. BLX rubber insulated fixed laying wires are suitable for electrical equipment and lighting device systems with AC rated voltage Uo/U of 300/500V and below, and the long-term allowable working temperature of the wires is 65℃. Its structure is aluminum conductor, extruded rubber insulation, outer woven wire and then coated asphalt material, and the role of coated asphalt material is UV resistance. Before and after the use of this cable for two years, the woven glass fiber often falls off and is damaged due to wind and sunlight, resulting in short service life, poor aging resistance and environmental pollution. With the continuous updating of national standards for cable products, according to the national requirements for safe and reliable electricity use, BLX-type cloth wires are not as good as overhead cables, so overhead insulated cables have gradually begun to replace BLX-type cables in the market.