Regardless of the cause, a short circuit in the electrical wiring is one of the most unpleasant (in terms of diagnosis and repair) malfunctions of any electrical circuit - in an apartment, private house or industrial premises. A particularly difficult case is the short circuit of hidden electrical wiring, because the wires are hidden under a layer of plaster. Even if the home electrician’s tools include devices that will help you find the location of the damage without opening the walls, you will still need to remove the wires to repair it.
Short circuit
What is a short circuit in electrical wiring? Why is it dangerous? How to find and eliminate it? How much does it cost to eliminate short circuits by an electrician from the housing office? What is the cost of searching for a short circuit with professional equipment? On this page we will try to answer all these questions in detail.
- Short circuit repair cost
- What is a short circuit?
- Why is a short circuit dangerous?
- Causes of short circuits
- Elimination of short circuits
- Finding a short circuit
- Short circuit protection
- When it is impossible to find a short circuit
Negative impact of short circuit for a person and his property
A short circuit, depending on the location of its occurrence, leads to detrimental consequences for property and the safety of human life. These include:
- burning and failure of electrical appliances;
- ignition of electrical wiring;
- a decrease in the voltage of the electrical network (in industrial conditions it leads to a shutdown of enterprises);
- decrease in the efficiency of power supply systems;
- the occurrence of electromagnetic influence leads to disruption of the functioning of communications located underground.
What is a short circuit?
Short circuit (SC) is an electrical connection of two points of an electrical circuit with different potential values, which is not provided for by the design of the device and disrupts its normal operation. Wikipedia
In normal human language, a short circuit is the connection of two opposite wires to each other, that is, the contact of the phase and neutral wires without a load between them.
Why is this happening? Why does a short circuit , and not a genie appear or another electrician not be born? You should know from your school physics course that any electrical circuit is a circuit. On one side there is a power source, and on the other there is a load (consumer). The power source in conventional electrical networks is a transformer substation, which in turn receives energy from power plants (CHP, HPP, NPP). Also, the power source in the circuit can be a simple battery, accumulator or generator. And the load or consumer can be any electrical appliance (light bulb, engine, heater, etc.).
Electric circuit
So, when there is a power source in the electrical circuit, but there is no load (consumer). When the circuit is closed (two wires are short-circuited), the current (Amperes) instantly increases to its limit values. In a short period of time, more thermal energy is released. This process is called a short circuit.
Short circuit in the electrical circuit
The amount of energy released and the short-circuit time are described by the Joule-Lenz law https://ru.wikipedia.org/wiki/Joule_-Lenz Law
By the way, the short circuit current (A) cannot be greater than the ratio of the supply power to the circuit resistance.
Why does short circuit current almost always cause a significant increase in temperature and can lead to fire? Because, at the moment of a SHORT CIRCUIT , there is an instant release of all the energy of the source. If you compare current with water, just imagine that the bottom of the bucket has come off.
You can take a regular AA battery and short-circuit it with foil or thin wire. In this case, you will see that all the energy of the battery splashes out in a short period of time. This will be quite enough to set something on fire.
Load more... Follow on Instagram
Elimination of short circuit consequences
If the search for the short circuit was successful, then it’s time to exhale and start eliminating it. What to do next depends on the extent of the damage to the electrical wiring. Regardless of the situation, before starting any repair work, you should definitely turn off the power to the apartment and make sure there is no voltage.
It is necessary to assess how much the cable insulation was damaged at the time of the short circuit. If there are swelling, darkening or melting, the wire must be replaced. If possible, it is necessary to assess its condition along its entire length.
Connecting wires in the distribution box using terminal blocks
If the wire covering is in order, then the immediate location of the short circuit is removed. The surviving ends of the current-carrying conductors are stripped and connected using Wago terminal blocks, welding, soldering or crimping. In low-current circuits, you can use regular fast twisting at your own risk. However, the PUE (7th edition, clause 2.1.21) does not provide for and does not approve of this method of connecting cables.
Why is short circuit current dangerous?
It is a well-known fact that one of the most common causes of fires is short circuits. In addition to the risk of fire, short circuits also damage various electrical equipment, including expensive ones. As described above, a short circuit current even from a small battery can light a match, let alone short circuits in household networks of 220V and 380V. Do not underestimate this dangerous phenomenon. In some cases, short circuit can cause temporary loss of vision and even serious burns.
Correct use of sockets
But of course it’s better to just not let the outlet catch fire. Indeed, in most cases, we practically set the socket on fire with our own hands by mishandling it. Therefore, we will give just a few simple rules that will allow you to avoid getting into such a “hot” situation.
- We will not advise you not to insert foreign things into the outlet, not to water it, and not to do other completely obvious things. Here are the rules that everyone has probably heard about, but for some reason forgotten.
- First of all, remember that each outlet has its own current rating. This parameter is set based on the power of the contact part of the socket. Typically, sockets are made for a current of 6A, which approximately corresponds to devices with a power of 1.3 kW. There are sockets for 10, 16 and 25A, the price of which is naturally slightly higher. More powerful devices can be connected to them. But their power still should not exceed the rated current of the outlet.
In the photo you can see where to look at the rated current of the outlet
- The socket must be firmly fixed in the seat. There should be no play when pulling the fork. Otherwise, each time the socket is used, the wires will be subject to deformation, which will ultimately lead to their breaking and poor contact.
- Do not insert larger diameter plugs into outlets. This leads to deformation of the contact part of the plug and, as a result, poor contact. This in turn leads to heating.
Remember! The higher the resistance of a conductor, the more heat it generates when current flows. At the same time, the higher the temperature of any conductor, the greater its resistance. It turns out that the more the wire is heated, the less current it can normally pass. Therefore, an overheated wire will certainly burn out during further operation.
- If the plug or socket shows burnt marks as in the video, be sure to remove the voltage from it and clean it. Otherwise, it will inevitably lead to fire.
Causes of short circuits
The main cause of short circuits is violation of electrical wiring rules and serious electrical installation errors. Electrical equipment is also a common cause of short circuits.
Short circuits in the chandelier and sockets
Short circuits in chandeliers most often occur at joints, in sockets and under the ceiling. A poorly secured cartridge becomes twisted over time and the wires close together. There are also cases of intersections of contacts inside the socket itself and short circuits in the light bulbs themselves (defects).
Short circuits in plugs and surge protectors
The reasons for short circuits in plugs of electrical appliances are very similar to the reasons for short circuits in sockets - the wires get twisted, the insulation is broken and a bang occurs. Some cheap surge protectors can also cause a short circuit within themselves. This usually occurs due to overload and melting of the insulation inside the extension cord. Short circuits in cheap extension cords are often due to thin wires.
Short circuits in sockets, switches and junction boxes
Short circuits in sockets and panels often occur due to a mismatch between the cable cross-section and the load on it. Poorly clamped (twisted) contacts also cause insulation melting. The wires heat up - the insulation melts - a short circuit occurs
Short circuits from water
Another very rare short circuit is a short circuit through water. This happens when water or moisture enters the switching point, when exposed contacts are close together, thereby causing a short circuit. The best protection against this type of short circuit is an RCD.
The most common causes of short circuits are poor-quality wire connections: poor contact, twists, uninsulated wires, mechanical damage to the insulation. This happens in places where wires are switched (in junction boxes, sockets, connection points). Short circuits can also occur in places where the cable is strongly kinked.
The second most common cause of short circuits is the malfunction of the electrical appliances themselves. That is, a short circuit occurs inside the device. This could be a surge protector, a phone charger, an electrical plug, a chandelier or an electronics board.
Preventive measures to prevent short circuits
Most short circuits and the fires they cause can be avoided. To do this, you should follow simple rules:
- Do not overload the electrical wiring with power (current). Select the cable cross-section and lay it in accordance with the requirements of the PUE.
- Periodically inspect the electrical panel, sockets and switches. The smell of burning, smoke, sparking and crackling are harbingers of a short circuit and fire.
- Replace old circuit breakers with new ones. Especially if a revision of the shield has not been carried out since Soviet times.
- If you use fusible plugs at the entrance to the apartment, then under no circumstances place so-called bugs on them. Even if an electrician I know “did this 100 times and everything was fine.” It is best to replace traffic jams with automatic machines.
If you notice that there is a burning smell coming from the electrical panel or switchgear, immediately notify the management company. The actions of the emergency service will be aimed at preventing short circuits and inspecting equipment.
A short circuit is one of those problems that are easier to prevent than to correct the consequences. Any wiring, various devices and panels require periodic inspection by a specialist. Compliance with this rule will ensure long and safe operation of electrical equipment.
If it was not possible to avoid a short circuit, then you need to think about its causes. Wiring that is old, too thin or damaged by animals must be replaced. Damp - dried and further tested by a professional electrician using a megger or more advanced instruments.
Elimination of short circuit, cost of elimination
The whole process of eliminating a short circuit comes down to the fact that you need to disconnect the closed (shorted) circuit. The hardest part about troubleshooting a short circuit is finding it. Therefore, the cost (if you turned to the services of an electrician ) of elimination directly depends on the volume of search work: on the area of the room and the complexity of the wiring. The main difficulties in the search may be unauthorized interventions in the wiring and unqualified electrical installation.
Why are there short circuits in wires and contacts?
The main factor of a short circuit is a breakdown of the insulation of current conductors. Violation of the integrity of the insulating sheath of wires, breakdown of contact resistance in an electrical or electronic circuit - all this causes a short circuit.
The main causes of short circuits include:
- high voltage surge;
- insulation wear;
- mechanical damage;
- penetration of foreign objects;
- lightning strike.
High voltage surge
Voltage fluctuations in the centralized power grid are often observed in remote areas of rural areas; such cases also occur in urban environments.
During a voltage surge that far exceeds the permissible standard, the risk of breakdown of the insulation of wires or electrical circuits increases sharply. A situation is created in which the wiring shorts and a short-term arcing may occur.
Insulation wear
The old dielectric sheath of wires dries out over time and can self-destruct. Failure to replace old wires over decades often leads to short circuits.
Mechanical damage
External mechanical impact on the electrical network leads to damage to the insulating layer of conductors. An example of this would be drilling into walls with hidden wiring. A drill caught between the wires causes a short circuit.
Penetration of foreign objects
Dust and small debris that get inside the housing through the cracks of the ventilation grille of an electrical or electronic device most often provoke the occurrence of a short circuit between the elements of the device. Short circuits are sometimes caused by insects and small rodents.
Lightning strike
Natural electrical discharge “attracts” the electromagnetic field of various electrical equipment. A powerful magnetic circuit can become the target of lightning.
How to find a short circuit?
To find a short circuit with your own hands, you do not always need to have special devices with you. In some cases, you can do without a professional. tool. Of course, in the practice of our electricians, there have been cases when a short circuit could not be found. But we will write about these cases at the very end.
| Visual inspection | Melting, smell |
| For cotton | A method for experienced electricians with big ears |
| Opening | Analysis of all electrics and panels |
| Calling | Calling circuits with a multimeter |
| Locator | Professional equipment and specially trained people |
Visual inspection
The first and most humane way to find a short circuit is a visual inspection. Of course, if you are not a professional electrician, then the so-called visual inspection may take more than one day. But, first of all, it is necessary to start the inspection from the “heart” of the wiring - the electrical panel. Then you need to turn off all electrical appliances from the sockets and turn the light switches to the off position. Carefully inspect all sockets and open switching points. It is also recommended to inspect the junction boxes, with free access to them. A characteristic presence of a short circuit may be a burning smell, for example from an outlet.
Burnt out sockets
The second method is by cotton
This is the easiest and fastest way to find a short circuit. Many people, even seasoned electricians, often forget about it. If there is a bang in a place other than the machine gun switchboard, then the short circuit needs to be looked for there. Of course, this method also has its disadvantages that you need to know and understand. When using this method, the main thing is not to damage the equipment or burn all the wiring or the apartment.
Electrician big ear
Third method - Autopsy
Don't be alarmed, opening means that you need to open all sockets , junction boxes and other switching points (chandeliers, lamps, switches). Of course, you need to take into account that later they will have to be collected back.
The fourth method is dialing
If a visual search and opening does not help, the next step in the search may be to test all electrical circuits with a multimeter. Using a continuity test, you can localize the problem section of the circuit. When dialing, all circuits are disconnected (that is, everything is disassembled): sockets are opened, lines from machines are disconnected, chandeliers are disconnected, wires in junction boxes are untangled. After which, each section of the circuit is called for the presence of a short circuit SEPARATELY . All this must be done sequentially - from simple to complex.
Method No. 5 - special equipment
Well, the highest point of professional search for short circuits is searching with the help of a professional tool (and a trained brain). A professional search for a short circuit is carried out by a route finder . The magic device will be able to accurately show the location of the short circuit. Of course, before working with a locator, it is necessary to carry out preparatory work and have some skills of a good electrician.
How to eliminate sparking in an outlet
Having dealt with the reasons, let's move on to ways to eliminate each of them. Let's start in the same order:
- Mismatch between plugs and sockets can be easily resolved. It is necessary to bring them to a single type. We recommend choosing modern standards, otherwise you will need to change the plugs on each newly purchased electrical appliance. That is, we are replacing Soviet sockets with European standards. In addition, if the house has vintage electrical equipment, we replace the old plugs on it.
- To eliminate an outlet overload, you can go in several ways:
- Replace the electrical installation device with a more powerful one. For example, if the outlets are rated at 10.0 A, then replace them with 16.0 A products.
- If one outlet is not enough, then install an outlet block. This will be much more reliable than using a tee. If for some reason there are difficulties with installing the socket block, use a double socket installed on one seat. Double socket
- You can try to repair a worn plug connector if the case is not very advanced. To do this, you need to remove the socket (after de-energizing the line from which it is powered), clean it, and then bend the contact plates using duckbills (thin pliers). If the socket cannot be repaired, we replace it.
Methods of protection against short circuits
Let's consider such an important question: how to protect yourself from a short circuit? The answers are obvious and on the surface:
- It is necessary to use high-quality electrical equipment, cables with the appropriate cross-section and high-quality insulation (NYM, VVG).
- Entrust wiring installation only to people specially trained in electrical installations. Because knowledge of the existing norms and regulations in the energy sector is their direct duty and area of responsibility.
- For fire protection purposes and wiring protection in general, it is necessary to use short circuit protection devices: circuit breakers, RCDs, differential circuit breakers and various relays. It is also worth paying attention to a high-quality cable, with an appropriate cross-section and good insulation.
- We also recommend that all our clients, when installing new wiring, avoid junction boxes. Deep switches and sockets work great instead.
- Once a year you need to inspect all wiring: stretch contacts in panels, sockets, switches; remove dust from contacts and machines. These methods will not only save you from short circuits, but will also reduce the likelihood of fires.
How to prevent an encounter with a short circuit?
Attention to all elements and regular checking of the network is the best way to avoid getting familiar with short circuits, and therefore, searching for an answer to the question of how to find a short circuit in hidden wiring. Periodic inspection of the electrical network will help reduce the likelihood of encountering a dangerous phenomenon. It will not give a complete guarantee, since not everything depends on the condition of the home wiring. However, it is still possible to minimize the chance of encountering a short circuit.
- If a socket or switch raises suspicions due to heating, sparking, or the appearance of a subtle but noticeable odor of plastic, then it is better not to wait for an emergency, but to replace or repair the device in time.
- Checking the electrical network once every six months is mandatory. During the inspection, close attention must be paid to the condition of the insulating materials. Even the slightest change in their color is a sufficient reason for replacement.
- The ideal is to install a machine equipped with a residual current device (RCD). If the circuit breaker de-energizes the network when a short circuit occurs, the RCD will protect the owners in case of contact with exposed wires.
- Before starting any serious work on the walls, you need to make sure that there is no electrical wiring in the area. This requirement is often forgotten, and then they pay for their inattention.
- The cross-section of the conductors must correspond to the total power of all household appliances, which in apartments and private houses is becoming more and more every year.
- A minimum amount of electrical equipment in “wet” rooms is encouraged. Sockets must have an appropriate moisture protection class: minimum IP44.
By fulfilling all these conditions, the owners minimize the chance of encountering a short circuit. A few words must be said about wiring installation. It is not recommended to lay cables tightly, as this increases the risk of damage.
When it is not possible to find a short circuit
Sometimes it is simply impossible to find a short circuit . And in some cases, even a professional locator will not be able to help. You have to lay a new line, change machines or change the entire wiring . This usually happens due to unskilled electrical installation. For example, large bundles of various wires are hidden under a thick layer of mortar and walled up somewhere deep in the wall (or floor). Moreover, these twists serve as a so-called switching unit, from which wiring throughout the apartment diverges in all directions. On top you can add broken wire insulation and current spreading across the floors. Such miracles happen, and unfortunately for the owners of such repairs, it cannot be treated by any devices or electricians.
With certain skills, you can find a short circuit with your own hands, BUT it is better to save your nerves, save money and call a real electrician by phone. The cost of eliminating a short circuit includes the guarantee that there will no longer be a short circuit in that location.
If you liked the article, please share it
Previously on the topic:
Share
Precautions when traffic jams are knocked out
The power supply of an apartment is a complex engineering system. At first glance, you already know what to do if the traffic jams are knocked out. But if doubts prevail and the matter seems serious, then it is better to solve this problem with the help of an electrician. He will carry out the restoration work safely and reliably. Here are some recommendations to avoid a traffic jam situation:
- Do not turn on several powerful appliances at the same time;
- Change wiring and electrical equipment in a timely manner;
- Install special protective covers on sockets in potentially hazardous places, such as kitchens, bathrooms, outdoors;
- After purchasing new household appliances, their power is determined and compared with the network rating;
- Carefully monitor the performance of electrical equipment connected to the electrical circuit;
- Children's rooms are equipped with sockets with special latches;
- In case of sudden flooding with water, the entire apartment is immediately de-energized.
- Do not install regular sockets in rooms with high humidity.
Remedies and prevention
First, they get rid of the reasons that caused the short circuit. The burnt wiring is replaced with new wires. Radio components and coils that have become unusable are replaced with similar new components.
Prevention of short circuits involves installing safety automatics, voltage stabilizers, replacing old equipment and worn wiring.
Safety circuit breaker block
Timely measures taken to prevent the occurrence of short circuits will preserve expensive equipment, electronic devices, and household appliances. We must remember that a short circuit can destroy not only property, but also people’s lives.
What to do when the lights go out
When the lights suddenly go out in your apartment, you should first determine the cause of this phenomenon. In most cases, you can do without outside help. To do this, make sure of the following:
- Availability of lighting in all rooms. If it turns out that there is no light in the entire house and in nearby ones, then the reason is most likely not in the internal wiring, but in an accident in the power supply system;
- Presence of voltage in sockets. For this purpose, you should use suitable equipment: an indicator, a multimeter and other portable electrical devices that will verify the presence of voltage;
- The performance of any household appliances with information indicators. If the lights on the microwave oven do not light up, it means it is not connected to the power supply;
- Availability of light in neighboring houses. In the event of an accident on a high-voltage line, the entire area may be without electricity.
If it turns out that the entire area is facing a problem, you will have to wait for the emergency team to arrive. If there is no electricity in a particular house, you should try to solve the problem yourself.
Safety precautions when working with electrical equipment: general information and basic measures
Let's sum it up
Everyone should know what to do if a short circuit occurs in an apartment or private house, as the consequences can be serious. Disconnect the line and call a technician to your home, who will quickly find the cause and location of the damage and replace the electrical wiring section.
Qualified craftsmen offer their services through the Tandem service. Call the service and we will quickly find a specialist for you. Electricians come to your home on the day you submit your application. You can also find a specialist on the website - fill out the required form and wait for a response from a specialist.
