From what aspects are the safety characteristics of wires and cables generally measured?

Since there are many standards related to the safety characteristics of cables, and there is no relevant standard for the safety characteristics grade of twisted pair cables and optical cables in Chinese national standards before 2014, many standards referenced in the domestic market come from international standards or American standards, and the focus of international standards and American standards on the safety characteristics of cables has always been different, Therefore, there are some deviations or misunderstandings in the market's understanding of the safety characteristics of cables. They think that the safety characteristics are flame retardant characteristics, or that the safety characteristics refer to low smoke and halogen-free. In fact, these understandings are incomplete.

Considering the safety characteristics of cables, it can be measured from five aspects: flame retardant characteristics, combustion performance, release characteristics, smoke characteristics, drip characteristics and toxicity.

① Flame retardant characteristics

The flame retardant of communication cable mainly refers to the characteristics that it can delay the spread of flame along the cable and prevent the fire from expanding. In other words, in case of fire, the communication cable is difficult to burn or can only burn slowly after encountering the fire, and after blocking the fire source, the flame will automatically extinguish within a certain delay distance and time, so as to prevent the expansion of the fire. The flame retardant characteristics of the cable are an important part of its safety and the basis of the safety of the whole cable. Only after the cable has good flame retardant characteristics can it prevent combustion, so as to ensure all other safety properties. Flame retardant properties of the communication cables are closely related to composition of the materials used.

② Combustion heat release characteristics

Combustion heat release mainly refers to the characteristics of the total heat release after complete combustion. Thermal energy release is one of the main factors causing damage to personnel's life in fire, and it is also the main factor causing damage to equipment in the data center. Therefore, the amount of thermal energy released by the cable is directly related to the size of the fire, the difficulty of extinguishing the fire, and the loss of people's lives and property. When considering the thermal energy release characteristics of materials, we should also look at the time point and degree of thermal energy release. The less heat energy is released, the later it is released, which is more conducive to fire control.

③ Flue gas characteristics

The characteristics of smoke in fire include high temperature, dimming, irritation, corrosivity, psychological terror, smoke loss in physical level, toxicity, explosion and environmental pollution in chemical level.

④ Drip characteristics

Flame dripping refers to the phenomenon that a material, especially nylon, plastic and other materials, melts and carries the fire source downward when burning. The temperature of dripping substances produced by the combustion of non flame retardant substances can reach 1000 ℃, which is a common situation in fire and another main cause of fire spread.

⑤ Toxicity

The toxicity of cables is closely related to the characteristics of smoke. Some toxic substances form visible smoke, or small particles in high-temperature smoke are toxic substances that cause death. The material toxicity of communication cables can be considered from three aspects: the products of combustion or decomposition of the material itself, the oxygen consumption of the material during combustion and the time to trigger the toxicity of the material.

This article is from Jiangsu Hansheng Cable Technology Co., Ltd. please indicate the source!