Fire-resistant cable knowledge

Fire-resistant cable refers to the cable that can maintain safe operation for a certain period of time under the condition of flame combustion. China's national standard GB12666. 6 (Such as IEC331) The fire resistance test is divided into two grades: A and B, with A flame temperature of 950 ~ 1000 ℃, continuous fire supply time 90 min, Class B flame temperature 750 ~ 800 ℃, continuous fire supply time 90 min, during the whole test period, the sample should bear the rated voltage value specified by the product. Widely used in high-rise buildings, subways, underground streets, large power stations and important industrial and mining enterprises and other places related to fire safety and fire fighting and lifesaving, for example, power supply lines and control lines for emergency facilities such as fire fighting equipment and emergency guide lights. 1. AC rated voltage: U. /U ( V Series: 600/1000 V, K series: 450/750 V, B series: 450/750 V). 2. The highest long-term operating temperature of the cable (1) Barrier vinylidene fluoride insulation and sheath: 70 ℃ and 105 ℃; Cross-linked polyethylene insulation: 90℃; (2) Fluoroplastic insulation and sheath: 220 ℃ and 260 ℃; Fluoroplastic insulation and 105 ℃ flame retardant polyvinyl fluoride sheath: 90 ℃ and 125 ℃. (3) Low halogen and low smoke flame retardant PVC insulation and sheath: 70℃; Halogen-free low-smoke flame retardant polyolefin insulation and sheath: 90 ℃ and 125 ℃. 3. Minimum ambient temperature :(1) Flame retardant PVC insulation and sheath: fixed laying-40 ℃; Non-fixed laying-15℃; (2)Fluoroplastic insulation and sheath: fixed laying-60 ℃; Non-fixed laying-20℃; 4. The safe laying temperature of cables shall not be lower than 0℃. 5. Fire Resistance: in line with IEC331 regulations, in line with GB12666. 6 Regulations, flame temperature 750 ℃, flame temperature 950 ℃-1000 ℃ flame temperature 750 ℃- 800 ℃ burning time 3h burning time 90min burning time 90min cooling time 21h additional voltage, rated voltage, additional voltage, rated voltage, additional voltage, rated voltage, additional current 3A additional current 3A additional current 3A Class A Class B 6. Recommended allowable bending radius for laying: non-armored and braided shielded cables should not be less than 6 times of the outer diameter of the cable; Steel tape armored cable should not be less than 12 times the outer diameter of the cable; Fluoroplastic insulation and sheath material cable should not be less than 8 times the outer diameter of the cable.