1. Classification and difference of flame-retardant cables
The ABC category of flame-retardant cables is classified according to the GB/T18380-2008 standard and is used to evaluate the ability of vertically installed bundles of wires and cables or optical cables to inhibit the vertical spread of flame under specified conditions.
1. Flame-retardant Class A means:Fire Retardant Cable is installed on the test steel ladder so that the non-metallic materials contained in the test in the total volume is 7L/m, and the fire supply time is 40 minutes. After the cable burning stops, dry the sample and measure The maximum carbonization range of the sample shall not be higher than 2.5m from the bottom of the torch
2. Flame-retardant Class B refers to: the cable is installed on the test steel ladder so that the non-metallic materials contained in the test in the total volume is 3.5L/m, and the fire time is 40 minutes. After the cable burning stops, dry the sample. The measured maximum carbonization range of the sample shall not be higher than 2.5m from the bottom of the torch
3. Flame-retardant category C refers to: the cable is installed on the test steel ladder so that the non-metallic materials contained in the test in the total volume is 1.5L/m, and the fire time is 20 minutes. After the cable burning stops, dry the sample. The measured maximum carbonization range of the sample shall not be higher than 2.5m from the bottom of the torch.
2. Which grade of flame-retardant cable is the highest?
It can be seen from the difference between the above three types of flame retardant ABC that the conditions of type A flame retardant are the most stringent, so the flame retardant rank order is A>B>C. A has the highest flame retardant level.
Three, flame-retardant cable application
Flame-retardant cables can be used in oil tank farms, important wooden structure public buildings, high-temperature places and other situations where fire resistance requirements are high and the installation and economic performance are acceptable. If self-contained oil-filled cables are laid in public corridors, passenger tunnels, bridges, etc. where fire protection is required, they can be laid in sand. Close to high voltage current,
For cable trenches of oil-containing equipment such as voltage transformers, the section trench cover should be sealed. When laying power cables in pipe bridges or exposed pipes, you need to choose fire-resistant ones. When laying through pipes in concrete, choose fire-retardant ones. Flame-retardant ones cannot replace fire-resistant ones, but fire-resistant ones can replace flame-retardant ones. When it comes to cost, it is better to choose cables with corresponding functions.