Prevention and suppression of the hottest cable fi

Prevention and suppression of cable fire

1. Cable failure causes fire

(1) poor manufacturing quality of cable head leads to overheating, explosion and fire of cable head during operation

(2) the insulation of the cable is aged after long-term operation, and the breakdown and short circuit during operation cause fire

(3) the long-term overload operation of the cable causes overheating and damage of the cable, resulting in short circuit and fire during operation

(4) the cable is mechanically damaged by external forces, causing insulation damage and short circuit, causing fire

(5) fire caused by oil filled cable leakage

2. External fire ignition cable

(1) electrical equipment failure and fire, resulting in cable fire

(2) sundries around the cable catch fire, causing the cable to catch fire

II. Measures to prevent cable fire

1 Ensure the construction quality, especially the production quality of cable head, must strictly comply with the specified requirements

2. Strengthen cable operation monitoring to avoid cable overload operation

3. Conduct cable test on schedule, and deal with it in time if it is abnormal

4. The cable trench and tunnel shall be kept dry to prevent the cable from being affected by moisture, which will cause insulation decline and short circuit

5. Clean the accumulated dust on the cable regularly to prevent the cable from catching fire due to the spontaneous combustion of the accumulated dust

6. Strengthen the regular verification and maintenance of cable circuit switch and protection to ensure its reliable action

7. When laying the cable, keep a sufficient distance from the thermal pipeline, and the control cable shall not be less than 0.5m; The power cable shall not be less than 1 meter. The control cable and power cable shall be arranged in separate slots, layers and layers, and shall not be placed in overlapping layers. On the other hand, the injection temperature is too high. For the parts that do not meet the requirements, the cables should take flame retardant and heat insulation measures

8. When installing the fire alarm device, it will produce great deformation during different tightening. The detection items will detect the fire and prevent the cable from catching fire

9. Take fire prevention and flame retardant measures. The fire prevention and flame retardant measures of the cable include: (1) wrap the cable with thermal insulation and fire-resistant materials. When the surrounding of the cable is on fire, the wrapped cable is isolated from the fire by thermal insulation and fire-resistant materials to avoid burning. If the cable itself catches fire, the fire may self extinguish due to the lack of oxygen in the binding body, so as to prevent the fire from spreading outside the binding body. (2) The holes where the cable passes through the wall, the bottom of the panel and the shaft are sealed tightly with refractory materials to prevent the expansion of the fire surface caused by the diffusion and spread of high-temperature smoke when the cable is on fire. (3) Paint the cable surface with fireproof paint. (4) Wrap the fire-proof part of the cable with fire-proof tape. (5) Heat resistant fire barriers are set between cable layers to prevent flashover between cable layers and expand the fire. (6) Sectional partition walls and fire doors are set in the cable channel to prevent cables from fleeing and expanding the fire

10. Equip necessary fire-fighting equipment and facilities. The fire of overhead cables can be put out with commonly used fire-extinguishing equipment, but automatic or remote fire-extinguishing devices should be installed at cable interlayer, shaft, channel and tunnel, such as 1301 fire-extinguishing device, water spray fire-extinguishing device, etc

III. cable fire fighting

toxic gases will be produced when cables are burned, so special attention should be paid to the protection of cable fire fighting. Precautions for extinguishing cable fire are as follows:

1 When the cable is on fire, the alarm shall be given immediately, and the cable on fire shall be removed from operation as soon as possible

2. Before putting out a fire, the power supply of the fire cable and adjacent cables must be cut off first

3. To extinguish the burning of cables, dry powder, carbon dioxide, 1211, 130L and other fire extinguishing agents can be used, and loess, dry sand or fireproof bags can also be used to cover. When the fire is large, spray water can be used to put it out. For tunnels equipped with fire doors, the fire doors at both ends of the fire section should be closed

4. Fire fighters entering cable interlayer, tunnel and trench shall wear positive pressure air respirators to prevent poisoning and suffocation. When it is uncertain whether the layout and development of strategic cutting-edge materials such as superconducting materials, nano materials, graphene and so on are all powered off, the firefighters should wear insulating boots and gloves. During the rescue process, it is forbidden to directly contact the cable sheath with hands

5. In the process of fire fighting, attention should be paid to prevent personal injury accidents such as electric shock, poisoning, collapse, falling and explosion

6. When professional firefighters enter the scene to put out a fire, they need to know the situation of live parts, high-temperature parts, high-voltage equipment and other dangerous parts

7. After putting out the fire, record, photograph and video the fire in time, and save the residual cable section at the fire for the analysis of the cause of the fire. Learn lessons and prevent similar accidents from happening again