What is an electrical fire?

Electrical fires refer to disasters caused by combustion caused by electrical reasons, accounting for a large proportion of fire accidents. Electrical fires may not only cause personal injury and equipment damage, but also lead to power outages in the power system, causing significant losses to the national economy. Therefore, preventing electrical fires is one of the important contents of safety work. Below, Siemens Electric Fire will give you a specific explanation

What are the causes of a fire?

1. Electrical equipment overheating. The main causes of overheating in electrical equipment are:

(1) Short circuit. When a short circuit occurs in the circuit, the current in the circuit will increase several times or even tens of times the normal working current, causing a sharp rise in equipment temperature. When the temperature reaches the ignition point of combustible materials, it will cause combustion. There are many reasons that can cause a short circuit in a circuit, such as insulation damage in the current carrying part of electrical equipment, equipment failure, and so on.

(2) Poor contact. Loose wire joints and low pressure on moving contacts can easily cause excessive contact resistance, leading to overheating at the contact area and causing a fire.

(3) Poor ventilation and heat dissipation. Lack of ventilation and heat dissipation facilities or damage to ventilation and heat dissipation facilities in high-power equipment can cause the heat generated during equipment operation to not be effectively dissipated, leading to equipment heat and causing fires.

(4) Improper use of electrical products. Failure to use electric stoves, irons, soldering irons, etc. as required, or forgetting to disconnect the power after use, can lead to a fire.

2. Electric sparks and arcs. Sparks and arcs are common phenomena in production and daily life, and electrical equipment can generate sparks and arcs during normal operation.

3. The temperature of electric sparks and arcs is very high, especially for arcs, which can reach over 6000 degrees Celsius. Such high temperatures can not only cause combustion of combustibles, but also melt and splash metals, forming a source of ignition.

What should be noted when extinguishing a fire?

After an electrical fire occurs, there are two possible phenomena: first, the electrical equipment catches fire or is still charged without being disconnected from the power source after causing the fire; Secondly, some electrical equipment (such as power transformers, circuit breakers, motor starting devices, etc.) may be filled with oil and may spray oil or even explode in the event of a fire, causing the fire to spread. Therefore, appropriate measures must be taken according to the characteristics of electrical fires when extinguishing fires.

Cut off the power. When an electrical fire occurs, if there is no power outage on site, the first step is to find a way to cut off the power supply. This is an important measure to prevent the expansion of the fire range and avoid electric shock accidents. When cutting off the power, the following points should be noted:

1. Reliable insulation tools must be used when cutting off the power supply to prevent electric shock accidents during operation.

2. The selection of the location for cutting off the power should be appropriate to avoid affecting the firefighting work.

3. When cutting wires, wires that are not in the same phase should be cut at different locations to avoid causing human short circuits.

4. If the wire carries a load, the load should be eliminated as much as possible before cutting off the power supply.

Prevent electric shock. In order to prevent electric shock accidents during the fire extinguishing process, attention should be paid to maintaining a necessary safety distance from the charged body during live fire extinguishing. Do not use water or foam extinguishers to extinguish the fire. Dry yellow sand and carbon dioxide fire extinguishers, as well as dry powder fire extinguishers, should be used for extinguishing fires. Prevent hands, feet, fire extinguishers, etc. from coming into direct contact with or being too close to energized parts. When extinguishing fires with electricity, insulated rubber gloves should also be worn.

Fire extinguishing of oil filled equipment. When extinguishing fires caused by oil filled equipment, attention should be paid to the following points:

1. When the external part of the oil filled equipment catches fire, carbon dioxide fire extinguishers, dry powder fire extinguishers, etc. can be used to extinguish the fire. If the fire is severe, the power should be immediately cut off.

2. If there is an internal fire in the oil filled equipment, the power should be immediately cut off. Use a spray water gun to extinguish the fire, and use sand, mud, etc. when necessary. The leaked oil fire can be extinguished with foam extinguisher.

3. When the generator, motor and other rotating motors catch fire, in order to prevent bearing deformation, they can rotate slowly, use a spray water gun to extinguish the fire and help them cool down, or use a carbon dioxide extinguisher to extinguish the fire.

What preventive measures can be taken?

(1) Regularly inspect the operation of electrical equipment, check for loose joints, presence of sparks, reliability of overload and short circuit protection devices, and good insulation of equipment.

(2) Reasonably select electrical equipment. In places with flammable and explosive materials, when installing and using electrical equipment, explosion-proof performance should be selected, and insulated wires must be sealed and laid inside steel pipes.

(3) Maintaining necessary safety distances is one of the important measures to prevent electrical fires. Flammable and explosive materials should not be stacked around electrical equipment that can generate electric sparks and hazardous high temperatures.

(4) Electrical equipment should be operated, maintained, and serviced by trained and qualified personnel to ensure its normal operation.

(5) Electrical equipment operating in flammable and explosive hazardous areas should have good ventilation to reduce the concentration of explosive mixtures, and the ventilation system should comply with relevant requirements.