The difference between flame-retardant cable and fire-resistant cable
It is easy for ordinary people to confuse the concepts of flame-retardant cables and fire-resistant cables. Although flame-retardant cables have many advantages that are more suitable for chemical companies, such as low halogen, low smoke and flame retardant. But in general, fire-resistant cables can replace flame-retardant cables, but flame-retardant cables cannot replace fire-resistant cables. The main differences between them are:
1. The difference in principle
The principle of fire-resistant cables is different from that of flame-retardant cables. The flame-retardant principle of halogen-containing cables is based on the flame-retardant effect of halogen. The principle of halogen-free cable flame retardancy is to separate the water when the cable burns and reduce the temperature to extinguish the fire. Fire-resistant cables rely on the fire-resistant and heat-resistant characteristics of the mica material in the fire-resistant layer to ensure that the cable works normally even in a fire.
2. The difference between structure and material
The structure and materials of fire-resistant cables are different from those of flame-retardant cables.
The basic structure of flame-retardant cable is:
(1) The insulating layer is made of flame-retardant materials
(2) Flame-retardant materials are used for the sheath and outer sheath;
(3) The wrapping tape and filling are made of flame-retardant materials.
The fire-resistant cable usually adds a fire-resistant layer between the conductor and the insulating layer. Therefore, theoretically speaking, a fire-resistant layer can be added to the structure of the flame-retardant cable to form a flame-retardant and fire-resistant cable. But this is actually not necessary.
Because of the fire-resistant layer of the fire-resistant cable, a multi-layer mica tape is usually used to wrap the wire directly. It can withstand long-term combustion, even if the polymer at the place where the flame is applied is burned, it can ensure the normal operation of the line.
3. Advantages and disadvantages
The clear concepts and advantages and disadvantages of flame-retardant cables, halogen-free cables, and fire-resistant cables
The characteristic of flame-retardant cable is to delay the spread of flame along the cable so that the fire will not expand. Because of its low cost, it is a large number of cable varieties used in fire-resistant cables. Regardless of whether it is a single cable or a bundle laying, the cable is known to control the spread of flames within a certain range when burning. Therefore, it is possible to avoid major disasters caused by prolonged fire, thereby improving the fire protection level of cable lines.
The characteristics of halogen-free low-smoke flame-retardant cables are not only good flame-retardant performance, but also halogen-free which constitutes low-smoke and halogen-free cable materials. It has low corrosiveness and toxicity during combustion, and produces a very small amount of smoke, which reduces the damage to people, instruments and equipment, and is beneficial to timely rescue in the event of a fire. Although it has good flame retardancy, corrosion resistance, and very little smoke concentration, its mechanical and electrical properties are slightly worse than ordinary cables.
The fire-resistant cable can maintain normal operation for a certain period of time under the condition of flame burning, and can maintain the integrity of the line. When the fire-resistant cable burns, the amount of acid gas smoke produced is small, and the fire-resistant and flame-retardant performance is greatly improved. Especially in the case of combustion, along with the water spray and mechanical combat, the cable can still maintain the integrity of operation of the line.