1. Avoid cable aging and damage The cable tunnel should […]
1. Avoid cable aging and damage
The cable tunnel should be naturally ventilated. When the normal load of the cable is used so that the air temperature in the tunnel is higher than 40 to 50°C, natural ventilation and mechanical exhaust ventilation can be used for ventilation. Ventilation system fan should be linked with the fire detector to ensure that the tunnel can automatically stop the wind when a fire occurs, the cable tunnel shall not be used as ventilation system inlet. The practice of influencing the ventilation and heat dissipation of cables should be avoided by keeping the fire doors of cables in the normally closed state, using cables to block the cables completely, and filling the gaps in the cover of the cable trenches. Moreover, the complete closure of the cable also makes it impossible to perform normal inspections of the cable and cannot detect cable faults in time.
2. Strengthen the cable's preventive experiment
After the cable is installed on the cable and cable accessories, a DC voltage withstand test should be performed. Compare and analyze experimental data. That is, it can be compared with the experimental data of the same cable, and can also be compared with the historical data of the cable to explore the laws of experimental data. If a DC withstand voltage test is performed, the measured leakage current has one of the following conditions, and the cable insulation may be defective, reflecting the defect site and handling it.
3. Prevent other equipment from igniting the ignition cable
There are oil-filled electrical equipment and coal conveying, pulverizing systems, and gasoline engine systems that can ignite the ignition cables. For them, corresponding measures must be taken: the cable trench cover near the oil-filled electrical equipment must be sealed, and the textile equipment flow to the cable trench to ignite the cable when the textile equipment fails to catch fire. The powder on the cable near the coal conveying and pulverizing system should be regularly cleaned to prevent the pulverized coal from spontaneously igniting the cable. The anti-riot door of the pulverizing system must have a fireproof slot box for the cable facing the explosion preventing the explosion-proof door action to ignite the ignition cable.
4. Use various measures to prevent the cable from igniting
Fire-retardant paint has a thin coating, does not affect the normal heat dissipation, and can play a good thermal insulation and flame retardant effect, but there are also many defects. Including improper selection of fire-retardant paints, there are counterfeit and shoddy products in the market; in practical applications, the results are not good, and there are peeling off of coating materials, uneven coating thickness, and cutting of materials. The use of fire-retardant coatings for fire-retardant paints should not be used for fire-retardant cables, and a large number of methods should be used for sealing, plugging, and blocking. Because of the flammability and stringiness of cables, in the event of a fire, the hazard is serious, especially in power plants and large substations. Once a fire strikes other circuits, we have problems with the use of cables and after installation. Still need to pay more attention to it. A little carelessness can cause fire.