There are six main causes of electrical fires
(1) Short circuit When a short circuit failure occurs in electrical equipment, a On the one hand, the current increases sharply, and the short circuit current is tens or even hundreds of times higher than the normal operating current, which generates a large amount of heat and causes a rapid increase in the temperature of electrical equipment. When the temperature reaches the ignition point of the insulating material, it causes combustion. On the other hand, not only are sparks and arcs generated at the short circuit point, but the higher temperature can melt the metal, causing nearby objects to burn and start a fire.
(2) Overload: When the electrical equipment is overloaded, if the protection device cannot act in time to cut off the poweration, long-term operation will cause excessive heating of electrical equipment and accelerate the aging of insulation. When the temperature reaches the limit of the insulating material, may cause fire at flammable temperatures. ? (3) Excessive contact resistance: The wire connection is the weak link in the line, which is the key element where overheating occurs. On the one hand, the insulation layer can. be damaged and cause a short circuit. On the other hand, poor contact at the joints will produce sparks and arcs which can directly cause fires. ? (4) Electric heating equipment (electric soldering iron, electric iron, electric soldering station, etc.) Improper use, flammable and explosive objects stacked nearby, and forget to cut after use. Power supplies, etc. can causefires. (5) Improper use and maintenance, long-term operation with illness, widening the scope of accidents (6) Bad weather, such as strong storms and rain, causing metal connections in pipes.Preventive measures against electrical fires:
?1. Improve the safety quality of electricians so that they understand how to install and install. electrical appliances. Safety requirements during use and maintenance.
2. The design of electrical equipment and circuits should be reasonable, the installation should be reliable, the use should comply with regulations, maintenance should be carried out in a timely manner, and fire hazards should be eliminated immediately when they are detected.
3. Power lines must not be overloaded. Large load equipment should notcannot be added to the aging lines originally designed. Power cords for mobile equipment should be rubber cords.
4. When using electric heating equipment, lighting devices and welding work, keep a constant safe distance from flammable materials. Electric heaters should be turned off immediately after use and stored until residual heat has dissipated.
5. Pay attention to power voltage fluctuations when the equipment is operating. If the voltage remains unstable for a long time, voltage stabilizing equipment should be used. The motor cannot operate without phase loss.
6. Televisions, audio equipment, etc. must be completely turned off after use. Otherwise, the primary side of the machine's transformer may still be loaded. Over thetime, it may consume electricity or burn out. the transformer in the machine. The electric mattress is thereThe high-end use should not exceed 4 hours.
7. The place where electrical equipment is used should have good ventilation and heat dissipation conditions, and a certain number of fire extinguishers should be equipped. No flammable objects should be stacked around electric heating equipment or under electrical circuits.
Sparks and arcing are important causes of electrical fires because the temperature sparking is relatively high. high, accessible (), flammable materials
1. Aging of wires
Aging of electrical wires is the most hidden danger problem. The aging of the wire insulation layer. and the contact of copper and aluminum wires. It is defective and lacks characterDedicated staff to check and maintain. Once a leak occurs, sparks may cause the insulating layer to burn and cause a fire;
2. wires
Short circuit is also an important hidden danger that causes electrical fires. When a short circuit occurs, the current can instantly rise to dozens of times the normal value, causing the line temperature to increase when it reaches. the combustion temperature of the insulation layer, an electrical fire occurs;
3. The switch is not closed
In daily life, lamps, electric heating equipment and other electrical equipment we use should be kept away from flammable objects. If the switch is not turned off when no one is present, there will be a risk of fire once the heat contacts flammable and explosive objects;
4. soudage
The use of electric welding tools cannot be avoided in home decoration. Safety protection measures should be taken when using them to prevent fires caused by sparks generated during welding from splashing flammable objects;
Sparks and arcing are important causes of electrical fires, because the temperature of the sparks is relatively high, reaching (3000°C to 6000°C), and is flammable. Objects can easily catch fire.
Electrical fires refer to disasters caused by combustion caused by electrical factors. Electrical accidents such as short circuits, overloads and leaks can cause fires. Equipment defects, improper construction and installation, poor electrical contact, high temperatures caused by electricalStatic icity caused by lightning, arcs and sparks are the direct causes of electrical fires. The storage of flammable and explosive materials constitutes an environmental condition conducive to electrical fires.
Causes of electrical fires:
(1) Short circuit failure in equipment or circuits. Electrical equipment will cause short circuit faults due to insulation damage, improper circuit repair, negligence, operation errors and unqualified equipment installation. The short circuit current can reach tens or even hundreds of times the normal current (proportional to the current). current square) occurs when the temperature rises beyond the ignition point of itself and surrounding combustibles, causing combustion, thus leading to a fire.
(2) Overloading causes overheating of electrical equipment, uunreasonable selection of lines or equipment and the load current of the line.
(3) The safety rated load capacity of the driver is exceeded and the electrical equipment is overloaded for a long time (exceeding the rated load capacity), causing overheating of the lines or the equipment and leading to fire.
(4) Overheating caused by poor contact, such as weak or loose joint connections, too low moving contact pressure, etc., causing excessive contact resistance. Significant overheating may occur. produce at the contact parts and cause a fire.
(5) Poor ventilation and heat dissipation. High-power equipment lacks ventilation and heat dissipation facilities or the ventilation and heat dissipation facilities are damaged, causing overheating and causing fires.
(6) Misuseof electrical appliances such as electric stoves, electric irons, electric soldering irons, etc. are not used as required, or forgetting to disconnect the power supply after use, causing overheating and fire.
(7) Sparks and arcs Some electrical equipment may produce sparks and arcs during normal operation. For example, opening and closing operations of high capacity switches and contactor contacts will produce arcing and sparking. The temperature of an electric spark can reach thousands of degrees. It can ignite on contact with combustible materials and explode on contact with a combustible gas.