According to the railroad station in Nanjing, at 18:20 on August 8, the Nanjing Yangtze River Bridge highway bridge below the attached place cable burst into flames and smoke, the fire department and the railroad units concerned quickly disposed of, affecting some trains late. The cause of the incident is under investigation.
In daily life, cable fires lead to fire accidents often occurring, and the probability of occurrence is also very frequent.
So, why would the cable catch fire?
Next, follow the ZMS cable company editor to see the causes of cable fires
1. Cable Overload Operation
Different specifications of the cable are corresponding to the load, such as the common household 2.5 square cable in the case of normal current and voltage, which can load the electrical energy in about 2500 watts.
If it runs under overload for a long time, it will cause the insulation material to overheat, and when the heat makes the cable temperature exceed 250°C, the cable rubber or plastic insulation will catch fire and burn.
If the cable “jacket” is damaged, it will also cause a short circuit and the risk of fire is even greater. In severe cases, the fire will start.
2. The Insulation Layer Is Damaged
The outer insulation layer of the cable can not only protect the construction workers from electricity but also the umbrella of the core material. When the insulation layer is damaged, the cable is prone to short-circuit and other faults, thus causing a fire.
3. The Cable Occurs Oil Leakage
This situation is mainly for the oil-immersed cable, when the cable is laid with a large height difference, it is easy to occur oil leakage. And the cable occurs after the leakage of oil, due to the loss of oil and drying, the thermal resistance of the upper part of the cable will increase, resulting in the insulation layer being scorched and pierced, prone to fire.
4. Line Short Circuit
The so-called short circuit is the AC circuit of two wires touching each other, the current does not pass through the line of electrical equipment but directly forms a circuit.
Such a large current through such a thin wire, due to the greater the resistance, the more heat generated, will be in a very short period so that the wire produces a temperature of up to thousands of degrees Celsius, enough to ignite nearby flammable materials, causing a fire.
5. Bad Contact
Due to poor cable joints, resulting in excessive contact resistance of the line and heat fire. Where the circuit has joints, or between the cable connection, or cable and switch, fuse, or electrical appliances connected.
If these joints are poorly connected, it will prevent the flow of electricity in the wire, and generate a lot of heat. When the heat is enough to melt the insulation of the cable, the insulation will catch fire, and ignite nearby combustible materials.
6. Line Leakage
That is because the cable insulation(isolation du câble) or its support material insulation performance is poor so that the wire and wire or wire and earth between a trace of current through. People often say that walking electricity, and running electricity is a serious phenomenon of leakage.
When the leakage is serious, leakage sparks and high temperatures can also become the source of the fire.
The Solution Is As Follows
1. Cut Off The Power of The Fire
Cable fire burning, regardless of what causes, should immediately cut off the power supply, and then, according to the path and characteristics of the cable through, carefully check to find out the fault point of the cable, and at the same time should quickly organize personnel to put out.
2. Cut Off Non-Faulty Power
When the cable trench in the cable fire is burning, if the cable laid side by side with the trench has a clear possibility of fire, then the power supply to these cables should be cut off.
If the cable is arranged in layers, the first will be the fire cable above the heated cable power cut off, then the fire cable side-by-side cable power cut off, and finally, the fire cable below the cable power cut off.
3. Close Cable Trench Fire Doors
When the cable fire in the cable trench, to avoid air circulation, to quickly extinguish the fire, the cable trench should be closed or blocked at both ends of the fire, using the method of asphyxiation.
4. Do a Good Personal Protection
As the cable fire burning will produce a lot of smoke and poisonous gas, when fighting cable fires, firefighters should wear gas masks. To prevent personal electrocution in the process of fighting, rescue personnel should also wear rubber gloves and wear insulated boots.
If a phase of high-voltage cable grounding, rescue personnel should comply with: indoor shall not enter within 4m from the fault, outdoor shall not enter within 8m from the fault point, to avoid injury across the step voltage and contact voltage. Rescuing injured people is not this limited, but should take protective measures.
5. Extinguishing Equipment
Extinguish cable fires should be used to extinguish fire extinguishers, such as dry powder fire extinguishers, “1211” fire extinguishers, carbon dioxide fire extinguishers, etc., can also use dry sand or loess cover.
If you use water to extinguish the fire, it is best to use a spray water gun. If the fire is fierce, and it is impossible to use other ways to put it out, after the power is cut off, you can flood the cable trench, with water to seal the fault fire.
6. No Hand Touching The Cable
when fighting cable fires, it is prohibited to directly touch the cable steel armor and move the cable by hand.
The above is about the causes and treatment of cable fire. ZMS cable company product quality is reliable, provides professional services and quality products, for customers to do a good job after-sales protection, trustworthy.