What are the main sources of electrical fires?

1. Short circuit**:

When the two wires are short-circuited, the current increases, the wire insulation layer is destroyed, the core temperature rises rapidly, and the insulation spontaneously combusts the disaster.

2. Ground fault voltage**:

Generally speaking, the impedance of the ground fault loop is large, and when the wire grounding connection is poor, the loop impedance is increased, and the arc fault is prone to occur, commonly known as sparking.

3. Overheating of wires:

Due to overheating, the wire will first scorch the insulating skin, emitting an unpleasant smell of burning rubber and plastic. Therefore, when you smell this smell, you should first think that it may be caused by electrical reasons, if you can't find other reasons, you should immediately pull the brake and cut off the power until the cause is identified.

Due to the concealment of electrical fire hazards, it is not easy to find and is prone to sudden occurrence under live conditions.

Electrical fires occur due to electrical energy sources. The main causes of traditional electrical fires are: leakage, short circuit, overload, poor contact, overload, arc, electric spark, lightning and static electricity.

In recent years, new causes of electrical fires have emerged, such as neutral wires, power surges, electromagnetic waves, etc., which cause high temperature and heat and ignite surrounding combustibles to cause fires. The prevention and control of electrical fires does not depend on post-fire measures, but on the early preventive measures of the electricity itself.

1. Leakage fire.

When the leakage occurs, the leakage current will flow into the earth on the way, if it encounters a part with a large resistance, it will produce a local high temperature, causing the nearby combustibles to catch fire, thus causing a disaster. In addition, the leakage spark generated at the leakage point will also cause disaster.

2. Short-circuit fire.

Due to the sudden decrease of resistance and the sudden increase of current during short circuit, the instantaneous heat generation is also very large, which greatly exceeds the heat generation when the line is working normally, and is easy to produce strong sparks and arcs at the short circuit point, which can not only make the insulation layer burn rapidly, but also melt the metal, causing the burning of nearby flammable combustibles and causing fire.

3. Overload fire.

When the conductor is overloaded, the aging and deterioration of the conductor insulation layer is accelerated. When severely overloaded, the temperature of the wire will continue to rise, and even cause the insulation of the wire to burn, and can ignite the combustibles near the wire, thus causing a fire.

The ignition source of electrical fire mainly includes some electrical equipment in the cabinet, as well as flammable materials such as cable skins of cables, and these flammable products are highly toxic after burning, and gas masks should be worn when extinguishing fires.

Electrical fire generally refers to the heat energy released due to the failure of electrical lines, electrical equipment, appliances and power supply and distribution equipment: such as high temperature, arc, electric spark and non-fault released energy;

For example, the red-hot surface of an electric heating appliance ignites the main body or other combustibles under the condition of combustion, and also includes fires caused by lightning and static electricity.

Electrical fires: Fires caused by electrical wiring.

It belongs to D metal fire, metal fire is different from general solid matter fire, and can be cooled and extinguished with the cheapest water. Theoretically, metal fires should be extinguished with special fire extinguishing agents such as 7150.

There are six types of fires:

Class A fire: refers to a fire of solid matter. This substance is usually organic in nature and can produce burning embers when burned. Such as wood, cotton, wool, linen, paper and other fires.

Category B fire: refers to a fire of liquids or meltable solid substances. Such as gasoline, kerosene, **, methanol, ethanol, asphalt, paraffin, etc.

Class C fire: refers to a gas fire. Such as gas, natural gas, methane, ethane, acetylene, hydrogen and other fires.

Category D fire: refers to a metal fire. Such as potassium, sodium, magnesium, titanium, zirconium, lithium and other fires.

Class E fire: refers to a live fire. A fire in which an object burns with electricity. Electrical fires such as transformers and other equipment: Class F fires: refers to fires of cooking objects (such as animal and vegetable fats) in cooking utensils.

Which category of fire does a live equipment fire belong to.

A: Category E. The types of fires are divided into six categories: ABCDEF.

a. Solid matter fire, generally carbonaceous solid matter fire;

b. Liquid fires and meltable solid matter fires;

c. Gas fires;

d. Metal fires;

e. Fire of live equipment;

f. Fire of animal and vegetable oils and fats in the pot;

If the electricity is not electrified, it is a Class A fire, and if it is live, it is a Class E fire.

The types of fires are divided into six categories: ABCDEF. a. Solid matter fire, generally carbonaceous solid matter fire; b. Liquid fires and meltable solid matter fires; c. Gas fires; d. Metal fires; e. Fire of live equipment; f. Fire of animal and vegetable oils and fats in the pot; If the electricity is not electrified, it is a Class A fire, and if it is live, it is a Class E fire.

Once an electrical fire occurs, the consequences will be very serious, so it is very important to prevent electrical fires, and it is suggested that the CIIC Shengan electrical fire monitoring system, also known as the electrical fire comprehensive prevention and control management system, is composed of three parts: the grassroots electrical fire comprehensive detection equipment plus the transmission layer NB-IOT IoT transmission terminal, and the intelligent cloud platform electrical fire comprehensive monitoring and management platform; It integrates the triple combination of electrical fire hazard collection, wireless transmission of the Internet of Things and big data analysis of fire protection to establish a comprehensive prevention and control management system for smart electrical fires, which is convenient and practical to help you prevent accidents.

An electrical fire is divided into two situations in a fire.

If the electricity is not electrified, it is a Class A fire.

If electrified, it is a Class E fire.

1. If the statement is incomplete, it should be asked: which category of fire does the live equipment fire belong to? A: Category E.

2. The types of fires are divided into six categories: ABCDEF. a. Solid matter fire, generally carbonaceous solid matter fire; b. Liquid fire and meltable solid matter fire, C Gas fire, D Metal fire, E Fire of live equipment, F Fire of animal and vegetable oils and fats in the pot.

3. If the electricity is not electrified, it is a class A fire, and if it is live, it is a class E fire.

Because of some electrical fires.

Electrical fires, with sudden, hidden, rapid occurrence, now there are generally fire monitoring equipment, Guangdong business IOT electrical fire monitoring can reduce the probability of electrical fires, such as.

Electrical fires mainly include leakage, short circuit, overload, and contact resistance.

Excessive size of these sources of fire caused by fires.

What is an electrical fire?

Electrical fire generally refers to the heat energy released due to the failure of electrical lines, electrical equipment, appliances and power supply and distribution equipment: such as high temperature, arc, electric spark and non-fault released energy; For example, the red-hot surface of an electric heating appliance ignites the main body or other combustibles under the condition of combustion, and also includes fires caused by lightning and static electricity.

What to do if an electrical fire happens?

1. Power off and fire fighting. In the event of an electrical fire, the power should be cut off as much as possible. The easiest way to lose power is to pull the power switch or disconnect the fuse of the faulty line.

Since the dielectric strength of these devices may be reduced in the event of a fire, this should be done with the help of insulating tools.

2. Charged fire extinguishing agents, such as carbon dioxide, should be used for live fire extinguishing.

Carbon tetrachloride, 2111, dry powder fire extinguishing, etc., are non-conductive. Foam fire extinguisher.

The fire extinguishing agent has conductive properties and can only be used to extinguish open flames, not to extinguish live fires. Electrified fire extinguishers should keep a safe distance from live bodies.

Which type of fire does an electrical fire belong to, it can only be said that it belongs to an electric fire because of electricity. Electrical appliances caused by short circuits, fires caused by explosions.

What category of fire does an electrical fire fall into? This may require a professional fire extinguisher to extinguish the fire.

Electrical fires are fires caused by electrical energy, and common ignition sources include leakage, short circuit, overload, poor contact, etc.

Electrical fires occur in summer and winter, because the temperature is high in summer and electricity is used, so the temperature of many electrical equipment will also be very high, resulting in damage to the insulator in the equipment and fire, and the winter weather is cold, the air humidity is small, and it is easy to generate electric charge, when the dry items and the air rub, there will be static electricity, which will lead to static electricity fire.

Which fire extinguisher can extinguish an electrical fire:

It needs to be treated with dry powder, carbon dioxide and other fire extinguishers, and the distance must be appropriate when using, such as equipment below 10 thousand volts to keep a distance of more than 40 cm, and if the electrical equipment is on fire at work, the power must be cut off before extinguishing the fire.

When an electrical fire occurs, it is necessary to find the source of the fire and then use a suitable fire extinguisher to extinguish it, so as to achieve the purpose of extinguishing it while ensuring our personal safety and avoiding many unnecessary problems.

There are four main types of electrical fires, namely: leakage fire, short-circuit fire, overload fire, and fire with excessive contact resistance.

1. Leakage fire.

The insulated wire is damaged and aged by natural or man-made factors such as high temperature, humidity, friction, corrosion, etc., and the insulation performance is greatly reduced, which may cause leakage.

When the leakage phenomenon occurs, the current encounters a part with a large resistance, which may produce a local high temperature, causing the surrounding combustibles to catch fire, thus causing a fire. In addition, arcs and sparks generated by leakage points can also cause fires.

The method of preventing leakage fire is also very simple, and installing a leakage protector can effectively prevent the occurrence of serious leakage short circuit. There is also a grip that non-electrical professionals are not allowed to work, so as to eliminate all kinds of human factors that can cause leakage.

2. Short-circuit fire.

Short-circuit fire is generally a fire accident caused by the short circuit of two wires, which leads to an increase in current, destruction of the insulation layer, and a rapid rise in the temperature of the wire core, resulting in spontaneous combustion of the insulating material.

In order to prevent short-circuit fires, the electrical acceptance specification stipulates that the area occupied by the wire in the piping should not exceed 40% of the cross-sectional area of the piping, so as to ensure air circulation and facilitate the heat dissipation of the wire. When laying wires, protective measures such as flame retardant piping, fireproof cables, and fireproof trunking are also adopted.

3. Overload fire.

When the conductor is overloaded, that is, when the amount of current passing through the wire exceeds the safe ampacity, the temperature of the conductor will continue to rise, which will accelerate the aging and deterioration of the insulation layer, and even cause the insulation of the conductor to burn, and ignite nearby combustibles, resulting in fire.

In order to prevent the occurrence of overload fire, the cross-sectional area of the conductor should be correctly selected according to the maximum working current of the line, and the electrical equipment should not be increased in the original line without authorization, and the load of the line should be checked at any time, and it is best to install appropriate safety devices.

4. The contact resistance is too large and the fire is fired.

On the electrical circuit with a large current passing, if there is a phenomenon that the contact resistance is too large somewhere, it is very likely to generate great heat in a local range, discoloring or even melting the metal, causing the wire insulation layer to burn, and causing the burning of nearby combustibles or dust, fibers and other substances accumulated on the wire, thus causing a fire.

If the contact points between wires and wires, wires and electrical equipment are not firmly connected, the contact resistance of the connection will be greatly increased, which increases the risk of fire, so the connection of wires and wires and equipment must be carried out in strict accordance with the specifications.

In addition, the connection points of the equipment in operation should be checked frequently, and the loose or heated situation should be dealt with in time; In places where the contact resistance is likely to be too large, applying color-changing paint or placing a temperature test wax sheet can also help to detect the overheating of the contact point in time.

Summary. There are two main forms of ignition sources of electrical fires: one is electric spark and arc; The other is the dangerous high temperatures generated on electrical equipment or lines.

There are two main forms of ignition sources of electrical fires: one is electric spark and arc; The other is the dangerous high temperatures generated on electrical equipment or lines.

1. The electric spark and arc are mainly generated in the gas or liquid cut off edge material, and after the insulation is damaged, the arc will occur between the gaps or cracks, so that the voltage of the arc between the two conductors is 30kV cm. The arc will produce a very high temperature, such as an arc current of 2 20A can produce a local high temperature of 2000 4000oC, and the arc current is enough to cause a fire. The electric spark can be regarded as an unstable, short-lasting arc, and its temperature is also very high, and the secondary ignition source generated by the electric spark and arc is more dangerous.

2. Electrical equipment and lines will always heat up during operation for the following reasons: The current generates heat on the resistance of the conductor; heat generated by core loss; Heat generated by the loss of insulating dielectric. Under normal circumstances, heat and heat dissipation can reach a balance at a lower temperature, this temperature does not exceed the long-term allowable working temperature of electrical equipment, there will be no dangerous high temperature, only when the normal operation is destroyed, so that the heat increases sharply and the heat dissipation can not be reached, then there may be a sharp rise in temperature, so that there is a dangerous high temperature, this dangerous high temperature will cause a fire when the conditions are right.