Electrical fires and safety

Causes of electrical fires

A short circuit fire is caused by a number of factors. Let's look at some of them in more detail.

Violation of insulation and contact

Damage occurs as a result of oxidation of contact surfaces, caused by overheating. An increase in metal temperature causes it to expand and touch the cables. As a result, contact of two polarities occurs, causing a short circuit.

Errors in connection and cross-section of wires

The cause of a short circuit in the apartment may be cable contacts. The interaction of copper and aluminum wires causes diffusion. As a result, gradual heating to high temperatures occurs.

Wire size is also important. Any cable is designed for a certain load. Exceeding the permissible values ​​at the joints causes heating, which can cause further ignition. Below is a table of correspondence between cable core thickness and maximum load.

Incorrect gasket

Cables located in the house, electrical room or on the roof of the room must be correctly connected and laid. Relevant for hidden wiring, where it is impossible to notice the moment of fire.

When installing a cable into a wall, you need to minimize sharp edges, as they can damage it during installation.

Questionable and faulty electrical appliances

The devices used must be of proper quality and have additional safety measures. For example, some kettle manufacturers increase the insulation of the wires, which reduces the risk of a short circuit.

Do not use devices with damaged plugs or cables.

Malfunction of protection devices

To minimize short circuits, a machine is installed at the entrance to the apartment. It will automatically turn off the power during a power surge, which will prevent a fire.

Damage to plugs and sockets

When electrical appliances are connected to the network, contacts interact, which become loose over time, leading to excessive heating. Such problems are characterized by crackling and sparking. The plug overheats, the socket melts, the contacts stick to each other, and a fire occurs.

Damaged socket

Causes of electrical wiring fires

If safety precautions are neglected, a fire may occur in the premises. Electric shock can also lead to serious consequences. We will look at the most popular causes of wiring fire below.

Technical difficulites . It is important to monitor the condition of all network wiring as well as their connections. This includes the main and distribution board, because it is in such places that the main cable routes are supplied, and various protective devices are installed. All devices must be in working order. Backup protection should be installed in the switchboards in advance, which can be used in the event of some dangerous situation (for example, short circuit protection). Basically, a fire in electrical wiring is possible due to poor contact, so you should pay special attention to the electrical wiring connections. For safety and reliability during operation, it is necessary to install protective shutdown devices in an apartment, in production or in workshops, especially where there is high humidity.

Moving smoothly from one reason to another, it should be noted that often a fire in the wiring in an apartment occurs due to the fact that the circuit breakers are incorrectly selected . The fact is that the purpose of the machine in the panel is to instantly operate in the event of a short circuit or overload in the network. So, with regard to overload, when choosing a circuit breaker, you need to pay attention to the fact that the rating of the circuit breaker corresponds to the cross-section of the wiring for which it is installed to protect. Otherwise, if there is an overload, the cable in the wall will begin to melt and may catch fire, and the machine will not work, or will work only when a short circuit occurs, which may be too late and will still lead to a fire in the house or apartment.

Improper or unsafe operation . Each device has a permissible load limit. The cause of the fire may be the connection of different splitters or extension cords into one outlet. Damaged plugs or cords from appliances pose a great danger. If, a short time after turning on an electrical appliance, the plug or splitter gets hot, this means that there is a problem in the contact connections.

Lighting group malfunction . Over time, lighting devices become the cause of fires. For example, it is necessary to protect an incandescent lamp from splashes, and a switch from moisture.

Technical faults include connecting an aluminum wire to a copper wire . Even if everything is connected correctly and the neutral wires are connected with a special strip, an electrical fire may occur. A strip made of brass material is not suitable for such connections, because over time it oxidizes and the aluminum and brass heat up, which consequently leads to a fire. If such a connection was inside a shield made of flammable plastic, then the consequences will be even worse, because instead of preventing combustion, it begins to melt and support the fire. It is possible to connect aluminum with copper if there is no other way to do the electrical installation. However, the connection must be made either through special WAGO terminal blocks or using special sleeves.

Another reason is poor quality and old sockets . After all, the plug of the electrical appliance itself must fit tightly into the socket. If the plug gets hot or sparks, replace the socket immediately. It's better to pay a little more, but buy a quality outlet. Although they may look the same, in cheap models the plastic heats up and catches fire, and the contacts do not have compression springs. We talked about how to choose sockets and switches in a separate article.

The next reason is old aluminum wiring . In old multi-storey buildings, distribution boards are located on the staircase. They are often in very poor condition, so there is a particular risk of fire. Also, in most old houses, the electrical wiring has never been changed, which means that it has already outlived its usefulness, the insulation becomes unusable, and, accordingly, does not protect against a short circuit in the wall. To this we can add that now they use much more electrical appliances than before, so the load increases on old wires, which can be aluminum and withstand small loads.

Today there is a problem of low-quality electrical goods . These products cannot withstand the load declared by the manufacturer. It is often necessary to troubleshoot problems in a house or apartment where the wiring has only recently been changed. After about a couple of years, the cable insulation cracks and begins to crumble, and this inevitably leads to a fire.

Some of the causes of wiring fires are clearly shown in the video:

Measures to prevent electrical fires

Preventing the sudden appearance of a lesion involves following these tips:

1. When laying the wire, you should take into account the cross-sectional reserve.
2. Insulate the cable with a gasket made of non-combustible materials.
3. Avoid connecting the edges of wires inside the walls of an apartment, house, or entrance. It is impossible to detect their damage before the fire occurs.
4. The cable used for wiring must be copper.
5. The connection between copper and aluminum darts must be made by using a brass sleeve with special clamps. The use of improvised means is prohibited.
6. If a malfunction of the device is detected, it is necessary to turn off the power to the apartment and call an electrician.
7. When leaving home, turn off appliances from the network. When leaving for a long time, turn off the power to the machine.

As you can see, a wiring fire on the roof of a microdistrict or in an apartment can be prevented before it starts. All that is necessary is to follow these recommendations.

Alas, not everyone knows whether the wiring smells before a fire or what to do when a fire appears. Let's talk about eliminating it in more detail.

10.11.2018 10:13:00

Procedure in case of fire of electrical appliances

Electricity is an integral part of every person’s life, which makes life easier and more comfortable.
However, if certain rules for using electricity are not followed or working with faulty electrical appliances can lead to property damage or pose a threat to human life and health. For example, many people live in houses that were built several decades ago, and the electrical wiring of the premises remains from those times. Of course, the condition of such electrical wiring leaves much to be desired, and if the wires are not replaced in time, a fire may occur and develop into a fire. Procedure in case of fire of electrical appliances: - do not panic, try to be collected and attentive; — quickly disconnect the device from the network (if the wire is on, use a wooden object, for example, a mop or broom); - call the fire department by phone 01, from a cell phone - 010, 112. Provide your name, exact address, floor, say what is burning and where; - further, if the device does not burn with an open flame, then cover it tightly with a thick cloth (bedspread, blanket, since the device can be very hot, therefore, the plastic, even durable in appearance, may turn out to be melted, which will lead to a serious burn) and, lifting , take it to the bathroom, then fill it thoroughly with water; - in case there is an open fire, knock it down with a rag or fill it with water and repeat the procedure as in the first case. If it is impossible to use water, try to cover the burning electrical appliance with soil from a flower pot, baking soda or washing powder; - Do not under any circumstances extinguish electrical appliances that are plugged in with water! If household appliances catch fire, you must turn off the power to the apartment or unplug the appliances from the socket if it is safe for your life. If you were unable to cope with the fire in the first minutes or it occurred in your absence and went beyond the initial stage of combustion, you must leave the room as quickly as possible. Turn off the electricity and gas, take your documents and money and leave the house, closing the doors tightly behind you. During a strong fire, if the fire cannot be extinguished and there is a lot of smoke, you should not open the windows - the flow of air supports the combustion and the flame will flare up even stronger. Do not lock the front door to allow free access for the fire brigade. Move through smoky rooms in a crouched position and cover your breathing organs with a damp cloth. Inform your neighbors about the fire and call the fire department immediately.

When leaving home, do not forget to check that all electrical appliances, such as irons, televisions, computers, etc., are turned off.

Vera KTOROVA

Photo from the website of the Main Directorate of the Ministry of Emergency Situations of Russia for the Tula region

What to do if there is a wiring fire

Statistics show that people often do not know the rules of conduct when an electrical cable burns. The algorithm of actions in such a situation is as follows:

1. De-energize the room. It is advisable to turn off the input machine.
2. Put out the fire. If necessary, you can call a neighbor for help.
3. When localizing the fire, do not touch surfaces. They're hot.
4. The fire extinguishing agents used must not conduct current.
5. If you realize that you cannot control the fire, call the fire department.

First actions

The causes of electrical panel fires in the entrances of microdistricts are often unknown. Despite this, the liquidation procedure has the following sequence:

1. Do not panic. Do everything quickly, but calmly.
2. Unscrew the plugs or turn off the machine.
3. Evacuate women and children.
4. Call the fire department.
5. Eliminate the air supply. Close the windows and doors.
6. Wet a towel and cover your nose with it.
7. Find the source of the fire. Use available means to eliminate it (blanket, soil from flowerpots).
8. If there is a great risk to your life, leave the premises. Wait for the rescuers. They will localize the fire and find out who is to blame.
9. After extinguishing the fire, call an insurance representative and demand payment of compensation.

How to stew

Localizing a wiring fire can be done in four ways:

1. Turn off the power to the burning network and use available means.
2. Use fire extinguishers that correspond to the fire class. This option is more suitable for enterprises.
3. Extinguishing non-de-energized wiring can only be done with sand or earth. The use of other improvised means is life-threatening.
4. To put out fires in winter, you can use a snowball. A well-aimed hit at the source of fire will short-circuit the wiring and the machine will turn off.

In order to prevent network overload or short circuit, it is necessary to make simple calculations. If the wiring in the electrical panel smells, in order to avoid a fire, you need to take the device and inspect it. There is a video that describes in detail how to do this. If you are not confident in your own abilities, call an electrician.

What to do before the fire department or rescuers arrive?

In the event of an electrical equipment fire, you must:

• De-energize the equipment as soon as possible (unplug from the electrical outlet or completely de-energize the room).
• Cover the burning electrical appliance with a fire blanket to prevent oxygen from entering.
• You can try to extinguish the fire by pouring water over the cloth over the de-energized appliance. You need to stand to the side, not in front or behind the equipment, as there may be an explosion that can cause injury.
• If it was not possible to quickly deal with the fire, and the fire spread beyond the body of the electrical appliance, immediately leave the room.
• Notify your neighbors about what happened.
• When leaving the room, close the windows and door tightly to prevent the spread of fire.

When electrical appliances catch fire or when a fire is detected, the algorithm of actions depends on the specific situation, as well as the conditions for the spread of fire. Don't panic and lose your composure.

It is necessary to contact the emergency services on call 101 or 112 as quickly as possible and report the fire, and try to reasonably assess the situation and act depending on your age, skills and capabilities, without putting your life in danger.

Actions in case of electrical fire

Electrical wiring fires occur when a person neglects the rules for operating the electrical system. Also, the cause of a fire may be working with faulty devices.

Basic reasons

Wiring may cause a fire if:

1. A short circuit has occurred. In such a situation, the temperature in the damaged area increases several times. During heating, wire elements melt. A short circuit can occur due to mechanical damage to the insulating material, increased voltage, old wiring;
2. There was an overload. This can happen if devices with increased power are additionally turned on; in some areas the temperature increases significantly. These factors lead to overheating, then fire occurs;
3. The conductor connections were broken. When the contact is weakened/oxidized, the contact resistance increases significantly. As a result, overheating occurs, which leads to fire.

The most common cause of electrical fires is a faulty power cord of an electrical appliance.

Actions to prevent fire

When a person connects one/several devices to the network and hears a distinct smell of plastic, immediate action should be taken. The smell of burnt plastic is a sign of an electrical fire.

Extinguishing method or procedure to prevent a fire:

• Repair operations must be carried out in a de-energized room;
• In the location where the smell of plastic is clearly noticeable, it is necessary to disassemble the sockets and check the contacts;
• If the reason is not found, you need to open the junction box. Here weak contact will be immediately visible. Outwardly, it will look like a melted cable.

If the wires in the socket are faulty, you need to clean them and restore the contacts. If a fire occurs in the junction box, you need to remove the damaged section and replace it with a new cable with an identical cross-section.

If the fire occurs over a large area, then the entire cable must be replaced. Otherwise, a fire will occur.

How to put out a fire

Electrical wiring with aluminum elements has less fire safety than copper wiring. Experts note that most fires occur in houses with old wiring. Fires can occur due to improper maintenance and equipment malfunctions. The consequences of a fire are extremely dire. The premises are completely burned out, and only the foundation may remain of wooden houses. All furniture, appliances, etc. burn out in a matter of minutes.

For extinguishing there are certain means, united by a common name - primary extinguishing agents.

• Fire extinguisher;
• Water;
• Sand;
• Other inventory.

Before choosing primary extinguishing agents, you need to know that they are advisable to use only at the initial stage of a fire.

If a fire occurs and the necessary elements are not at hand, you can use soil from flower pots.

How and with what to extinguish a fire in live wiring

Electrical wiring can catch fire when there is no person nearby. To put out a fire, you need to act with lightning speed. As we wrote above, the initial stages of a fire can be disqualified using earth/sand. However, for such cases, it is better to have a fire extinguisher in the house. It is worth remembering that not every fire extinguisher is suitable for extinguishing live electrical wiring. The fire class is also important.

Which fire extinguisher can be used to extinguish a fire caused by faulty electrical wiring, the voltage of which is up to 10,000V? A carbon dioxide fire extinguisher is suitable for this. The product has a low temperature and is supplied under pressure. Thanks to this, a person will be able not only to disqualify the source of fire, but also to cool the smoldering areas. As for the disadvantages, these include the release of harmful vapors. A carbon dioxide fire extinguisher cannot be used in rooms that are not ventilated. Otherwise, the person will be poisoned by the fumes.

For houses/apartments where the voltage is no more than 380V, a powder fire extinguisher is suitable. It can be used to extinguish fires in installations up to 1,000V. Elimination of fire occurs by isolating the flame from oxygen.

If you can turn off the power quickly, you can put out the fire with a foam/water fire extinguisher. If it is not possible to turn off the power to the house, it is prohibited to use these types of fire extinguishers. Otherwise, the person will die from electric shock.

How to protect yourself from electrical fires

• It is forbidden to use many tees;
• Extension cords should be routed around the perimeter of the room. Heavy objects should not be allowed to rest on them;
• The maximum current for a single-phase socket is 16A. If this threshold is exceeded, the outlet becomes dangerous;
• The junction box should be checked every six months. If oxidation has formed, it is necessary to eliminate it. Other contacts should be checked for serviceability and strength;
• The condition of the sockets must be constantly maintained. It is important not to allow the clamping contacts to become loose. If the sockets have not been changed for a long time, they may begin to spark when any device is plugged into the network. This is a sign that the outlet urgently needs to be replaced.
• Don’t ignore switched on electrical appliances;
• If a person plans to leave the house for a long time, it is worth turning off the power to the room. Then you can be sure that nothing will happen to your home;
• If possible, it is worth running a separate line for electrical appliances that have increased power. This will relieve the wiring from being overloaded.