Discuss how to troubleshoot electrical wiring. What are wiring faults and how to fix them? The main measuring and indicator devices necessary for repair

The presence of electricity in the house ensures the comfort of its inhabitants and successful activities in various fields. In the event of a malfunction in the electrical wiring networks, the usual rhythm of life is disturbed. In order to quickly eliminate this problem, you need to have certain knowledge and practical skills. In the article we will consider wiring malfunctions in a house, apartment and methods for finding and fixing the problem.

Basic rules for installing electrical wiring in apartments and private houses

In order to quickly identify faults in electrical wiring networks and navigate in places where it is laid, recommended to read typical schemes and installation requirements.

The starting point from where the power supply comes from and is distributed into groups in private houses and apartments is the introductory switchboards (ASU). The main elements of the ASU:

• Introductory circuit breaker to the metering station (electric meter);
• electric meter;
• Residual current device (RCD);
• Protective automatic switches for various groups of consumers, lighting, sockets, heating appliances, and other household appliances;
• Plank (tire) for fastening zero wires "N";
• Tire (bar) for fastening ground wires "PE".

Wires are routed from the machines of each group through junction boxes to sockets, switches, and lighting fixtures. Household appliances that consume high power electricity are connected by a separate wire, through an individual machine.

Photo No. 1 an example of connecting group machines to the ASU

To make it easier to navigate during the repair process, circuit breakers in the ASU are marked with inscriptions:

• lighting;
• sockets;
• boiler for heating water;
• air conditioner;
• electric stove (in the kitchen) and other possible consumers of electricity.

It is not always necessary to deal with ideal conditions when the groups in the ASU are signed. In such cases, it is necessary to be guided by the fact that circuit breakers are installed taking into account the maximum possible power of electrical appliances in a given section of the circuit. Practice shows that in apartments and private houses on various groups, automatic machines with tripping currents are installed:

• lighting group from 10 A to 16A;
• sockets 16 - 25 A;
• washing machine 25 A;
• electric stove 25A.

The thickness of the wire in groups in different parts of the circuit may vary:

1. Socket chains on the main line between junction boxes are laid with wires with a cross section of 4 sq. / mm. From the boxes to the outlet, a thinner wire is laid, with a cross section of 2.5 sq. / mm.
2. In lighting circuits, wires with a cross section of 2.5 sq. / mm are laid between junction boxes. From the box to the switch and the lighting device, wires 1 - 0.75 sq. / mm are used.
3. Separate wires from the ASU are laid on air conditioners and electric stoves, bypassing junction boxes, with a cross section of at least 6 sq. / mm.

Table number 1. Characteristics of cables often used for wiring PUNP and PUGNP

By requirements of the PUE(Rules for the operation of electrical installations) installation of power supply to residential facilities is carried out according to a three-wire scheme. Cables with three double-insulated copper wires with different colors are used:

• blue or black wire is used as neutral zero "N";
• red or brown connects to phase;
• yellow - green is connected to ground.

Photo No. 2 Three-wire cable with wire marking by color

All these requirements form certain signs that indirectly facilitate the troubleshooting of electrical wiring and ensure the safety of workers.

Features and differences of electrical wiring in apartment and private houses

In modern apartment buildings the power supply scheme is carried out according to standard designs, with wiring hidden under plaster. Switchboards with metering devices are located at the entrances on the landing. In some cases, in the entrance there is only a common machine and a meter for the apartment, group circuit breakers are placed in a separate switchgear (switchgear) in the apartment.

In private houses, in addition to traditional lighting groups and sockets, outbuildings can be allocated to a separate wiring group:

• workshop;
• sauna;
• street lighting:
• garage power supply;
• a barn with rabbits and other options.

Depending on the building material, in wooden structures exposed wiring methods in plastic cable ducts may be used. Connections between buildings are carried out by underground cable or overhead lines. Each building can be equipped with its own switchgear with group automatic switches.

The most common electrical wiring faults in private and multi-apartment buildings

The causes of malfunctions in electrical wiring are various, the most common:

1. A short circuit of the neutral or ground wire to the phase wire can occur due to lack of insulation, aging of the insulating layer or its burning as a result of excess current loads, unreliable contact at the joints. If the circuit breaker does not work, such a malfunction may lead to a fire;
2. Lack of phase or neutral wire contact in the junction box, on the terminals of switches, circuit breakers, sockets or lamp sockets. This happens from heating the contact connectors, not high-quality stripping contacts, insufficient tightening of the wire fastening bolts, on the contact group.
3. Breakage of wires, most often found at the points of connection to switches, cartridges, sockets. When replacing lamps, the wires at the cartridge are bent, in junction boxes and sockets during installation, the wire bends and breaks inside the insulation. This may not appear for some time, but then the weak contact will burn.
4. Violation of the integrity of the wires of hidden wiring can occur as a result of drilling walls;
5. There are times when circuit breakers in the switchgear break down, they can break the circuit or close. When switching, the electrical contacts do not close or open, sometimes the cocking mechanism jams, and it is impossible to switch it.

The main measuring and indicator devices necessary for repair

It doesn't take many expensive tools to find and fix faults in home wiring. An indicator screwdriver and a tester or multimeter are enough.

Indicator screwdriver

Indicator screwdriver can be of three types:

• With a neon indicator lamp, the current from the phase wire goes to the tip, through the resistance to the lamp, then to the contact of the handle where the person touches. The body works like a capacitor in this circuit. The currents are very small to kill a person, but enough to light a light bulb. With such an indicator, you can determine the phase with a voltage of 60V.
• Indicators with an LED indicator are self-powered by batteries, the principle of operation is similar to a neon screwdriver. In this case, the circuit includes a bipolar transistor, which enhances the sensitivity to the electric field. It is possible to determine not only the phase with a voltage of up to 60 V, but also to identify break points in cables and hidden wiring.

Photo #3. Indicator screwdriver with led lamp

• Indicator screwdrivers with a liquid crystal display have an LED, acoustic indicator and show the voltage in volts.

Multimeters

These devices are universal, they can measure current, voltage, resistance and be used as an indicator for continuity of wires, detect a short circuit in the circuit.

It is convenient to use models with digital indication, modern devices are produced with current clamps, which allows you to measure the load currents in the circuit using a non-contact method.

Table number 2 Comparative characteristics multimeters series DT-83

Troubleshooting Technique and Solutions

In the absence of voltage in the entire apartment or house, first of all open those ASUs, check that the power supply is supplied from the industrial network. At the same time, on modern appliances the LED indicator flashes, the old counters do not have such an indicator. In such cases, the presence of voltage is checked with an indicator screwdriver or multimeter. If there is no voltage, call the power supply company and make a request for troubleshooting.

If there is voltage at the output of the input machine and the meter, check the RCD, when it is triggered, the switch will be visible in the off position, turn it on.

When there is no voltage in a separate group, lighting or socket, also start the test from the position of the circuit breakers in the switchgear. If the machine constantly trips without a connected load in the circuit, there may be two reasons:

Fault number 1. Short circuit in circuit, turn off the circuit breaker, disconnect the phase wire at the output and ring the circuit with a multimeter phase - zero and phase - earth. To do this, you need to make sure that all load elements in the network of this group were turned off, exclude the passage of the indicator signal through their circuits, the device is set to the continuity mode. In the lighting network, turn off all switches, it is better to unscrew the bulbs, because the short circuit may be in a faulty switch.

Photo #5. An example of checking the presence of voltage on a phase wire with an indicator screwdriver

One clamp from the multimeter is applied to the wire disconnected from the machine, the second to the blue wires fastening bus N and then to the ground bus with yellow-green wires PE.

Practical Tip #1 - for reliability, you can disconnect the cable wires of the tested group from the busbars and conduct a short circuit test directly between them. If there is a short circuit between the wires, the multimeter will give a sound indication, zeros will appear on the LCD screen.

It must be understood that in the continuity mode, the device works as an indicator, this is not a measurement of circuit resistance. Using a multimeter to test a short circuit is effective in an apartment, in short sections up to a maximum of 8-10m with a good battery charge of the device. To check a short circuit in private houses, on long wires, between structures, poles street lighting it is recommended to use professional megohmmeters, type M-416.

When a short circuit is detected, it is necessary to identify the place or section of the circuit where it occurred. In order not to do unnecessary work, the elements of this group, lamp sockets, sockets, switches, junction boxes are visually inspected. Having found obvious signs, digging, melting of the plastic case, smells of burnt insulation, we remove these elements, disconnect wires from them. Sections of wires with molten insulation are cut off, the ends of the wires are separated in different directions to prevent a short circuit. Re-testing for a short circuit is done, in its absence, install a new cartridge or socket, you should not repair burnt elements.

Photo No. 6. Panel with controls for selecting the operating mode of the multimeter

If no suspicious elements are detected or a short circuit is not eliminated after their removal, the section of the circuit on which it occurred is determined. In the socket group from the socket to the junction box, in the lighting network from the box to the switch with the cartridge. Open the cover of the junction box, disconnect the phase wire of the outlet or switch being tested from the common twist of the phase wire connection. Check the multisite for contact between the phase - neutral and phase - ground wires, if any, the wire in this section of the circuit will have to be replaced.

A short circuit may occur in the area between the junction boxes and the ASU. In these cases, the technique is similar, the phase wire of the tested group is disconnected from the machine and in the first junction box. The presence of contact between phase zero and phase ground in this section is checked. Further, the phase of this group is turned off at the first and second junction boxes from the ASU, in the area between them, the presence of phase contact with zero and ground is checked. Sequentially ringing the circuit, the section in which the short circuit is sure to be determined.

Fault number 2. Faulty circuit breaker in the ASU

It happens that when one light bulb is turned on, the circuit breaker knocks out; if the wiring is in good condition, there is no short circuit, it is clear that the circuit breaker is faulty. It is possible that the permissible load current of the circuit of this group may be exceeded; to make sure of this, take current measurements. You can connect a pointer ammeter to the break of the phase wire and the circuit breaker, but it is more convenient to do this with a multimeter with current clamps. Measurements are carried out by a non-contact method, the required current measurement limit is set on the device. The pliers wrap around the space around the phase wire at the output of the machine, the digital screen shows the current strength in the circuit.

If the current is exceeded, turn off unnecessary appliances, faulty household appliances may consume large quantity energy. Specify the maximum current consumption of these devices according to the documents, take measurements, if the consumption is much more than declared, hand over the equipment for repair.

There are malfunctions in the circuit breaker; when switching, the contacts do not close or open. This is easily determined with a conventional indicator screwdriver. The presence of phase voltage at the input is checked, in the on position, the phase must be at the output. If it is not there, the device is faulty, when the phase is present at the output in the off position, this is also a sign of a malfunction, change the switch.

Open circuit

The absence of voltage at the ends of the wires for the socket or lamp socket indicates an open circuit. First of all, check the reliability of the contacts at the junctions. Next, use the multimeter in dial mode. It is necessary to disconnect the phase wire from the circuit breaker in the tested group, connect it to the neutral wire. The multimeter terminals are connected to zero and the phase of the outlet, if both wires are intact, an acoustic signal will sound, zeros will appear on the display. If there are no signals, in order to determine the zero is broken or the phase, close each separately in a pair with a ground wire and ring. If the break is in a pair of phase - the ground is interrupted, if the pair is zero - the ground is cut off. A break can be on three wires at once, in the ideal case it is necessary to change the entire section of the three-wire cable.

The damaged section is determined by successively disconnecting the phase and neutral wires of the tested group, between the boxes, between the socket and the box, the switch and the box. At one end they are closed, at the other they are connected to a multimeter, ringing. So you can ring any intermediate interval in the circuit of the faulty group.

There are more simple methods detection of a break in a hidden wiring that does not require disconnection and continuity of wires in the cable. In the event of a phase failure, you can use an indicator screwdriver that is sensitive to the electric field powered, battery operated. Putting your finger on the contact on the screwdriver handle, draw the tip along the surface of the wall under which the phase wire is laid. The indicator LED will light up, in the place of phase failure it will go out.

To determine the breakage of hidden wiring, special devices "Woodpecker" E-121 are used; MS - 158 M; BOSHDMF - 10 zoom. But these devices are used by professionals, certain knowledge is needed and they are expensive. In domestic conditions, it is easier to find a multimeter, a sensitive indicator screwdriver with measurement limits of 50mV-500V.

It is necessary to determine the break points and call individual broken wires in order to make connections. It is not always possible to replace a hidden section of wiring; this may be associated with costly repairs. Sometimes, in order not to crumble the plaster between the box and the socket, the wire that was used for zero is connected to the place of the broken phase, and the zero on the socket is connected to the ground wire. Connections according to this scheme work, there are different variants connections in order not to crumble the walls, but they can be used in extreme cases when there are no other options. To connect in places of a cliff, you have to remove small plot plaster, it is very important to make a connection at the break point with high-quality contact and securely insulate.

Methods for connecting wires in areas of faulty wiring

There are many proven ways to securely connect and extend wires:

• The easiest twisting of bare ends;
• Use of connecting blocks with screw terminals;

Photo number 7. sockets with screw terminals

• An effective way to connect when building up wires is the use of WAGO pads, they provide reliable current transfer even between wires of different metals.

Photo #8. Block WAGO

• There are special cylindrical sleeves for connecting the wiring, into which the stripped ends of the wires are inserted. Then the sleeve is crimped with a special key or pliers. Before connecting, a heat-shrinkable insulating tube is put on one of the wires, it is pulled over the sleeve and subjected to heat treatment. Then hermetically compresses the junction of the contacts.

Safety rules for repairing electrical wiring in apartments and private houses

The main task for safety during repair work with electrical wiring is not to touch bare live wires with open areas of the body. Especially when voltage measurements are made with a multimeter, the presence of a phase is checked with an indicator screwdriver.

Before carrying out work on disconnecting or connecting switches, sockets, lighting cartridges, stripping wires, ringing with a multimeter, make sure that the measuring and indicating devices are in good condition. Test the multimeter and indicator screwdriver on a properly functioning electrical circuit.

Turn off the machine on the ASU of the group where the work is being carried out, block the machine or put up a warning sign "do not turn on people working." Council number 2, for reliability, you can disconnect the wire at the output of the protective switch, close the doors of the ASU cabinet, keep the key with you. Before starting work on site, check the absence of voltage with an indicator screwdriver or multimeter. After making sure that the desired machine is turned off, there is no voltage, you can proceed with the installation work.

Frequently asked Questions

Question number 1. You can connect or build up wires from different metals?

According to the requirements of the PUE, all wiring in residential premises is not recommended with copper wire. Contacts with different metals heat up, unnecessary losses, increased power consumption, the risk of a short circuit and fire. In extreme cases, at low load currents, WAGO connection blocks are used; they provide high conductivity and low heating of the contact group.

Question number 2. Is it possible to use a two-wire cable in the area from the junction box to the luminaire, and a three-wire cable to the chandelier without a ground wire?

If the housings of the chandelier and lamp are plastic or made of dielectric material, you can. Products with metal case grounding is recommended.

Question number 3. Which model of circuit breakers is better to use in the ASU for separate groups?

Reliable modular circuit breakers of the ABB series, they have a wide range of current limits.

Table No. 3 electrical operating life circuit breakers different manufacturers

The vertical axis shows the maximum current loads during operation, the horizontal axis indicates the number of operations x per 1000 times.

Question number 4. Can you fix the circuit breaker yourself?

Replace defective switches with new ones. Self repair such a switch and further operation may lead to an emergency.

Question number 5. Can a ground wire be used instead of a neutral wire?

In certain sections of the circuit where the neutral wire is damaged, you can put a jumper from zero to ground. It is not recommended to disconnect the ground wire from the terminal of the socket or lighting device.

Electricity is an integral part of our life. In each apartment you can find more than a dozen devices that work from the power passing through the wires. electric current. All of them help to simplify and diversify our lives. However, over time, it will be necessary to repair the electrical wiring in the apartment. This is a rather difficult job that requires special care and attention.

Preparatory work

Before you repair the wiring, you must correctly select all necessary materials and tools. It is from them that the quality of the work performed will depend. Another important factor in the success of the repair is the strict observance of all stages of the process and taking into account the advice of professionals. They will help beginners avoid most mistakes and get the job done in the shortest possible time.

Choice of materials and tools

For successful repair work, you need to prepare several mandatory tools in advance. Their choice depends on what exactly needs to be repaired in the apartment. This preparatory stage it will help not to be distracted during work and not to look for this or that tool for a long time.

For different types wiring repairs may be needed:

In addition to the above tools, you will need some expendable materials. All of them are inexpensive and available in any store that sells electrical goods. These include:

1. Putty for sealing holes punched in the wall.
2. Electrical tape to secure the connection.
3. Cable wire for replacing unusable parts.
4. Terminals for a more durable and high-quality connection of wires.

Any repair work related to electric current poses a direct threat to life and health.

To avoid negative consequences and perform a quality repair, you must follow all the basic safety rules.

Among the most important tips experienced electricians can be distinguished as follows:

Determining the cause of the breakdown

Before proceeding with the repair, it is necessary to accurately determine the cause of the malfunction and find the damaged area. To do this, you need to remember the entire sequence of actions that led to the breakdown.

In most cases, these situations are:

Troubleshooting

During operation electrical appliances various problems may occur. To eliminate them, you need to call an experienced electrician and spend a considerable amount of money on his services.

However, this work can be done independently. It is important to have at least a little experience in such repairs and follow all safety regulations.

Partial renovation

This type of repair is the most frequent, as it does not affect the entire apartment, but a separate section of it. The need for partial repairs may arise when the power supply to any outlet or switch is interrupted. In this case, the following actions are performed:

Complete replacement

If done overhaul in an old room or apartment, it is best to start work with a complete replacement of the electrical wiring. This will help to avoid accidents and possible fires in the future. Complete replacement wiring is done as follows:

Repairing electrical wiring in an apartment is a rather complicated undertaking that requires the contractor to be attentive, accurate and knowledgeable in their field. At right approach and following all the recommendations of professional electricians, you can quickly fix any problem.

During operation, it is very important to follow the safety rules. They will not only save lives, but also help maintain health.

A banal electrical fault can cause a lot of trouble. First, it's some material costs, secondly, the loss of time and other inconveniences. But not always in such cases, the help of a specialist is required. Often, troubleshooting is quite possible on their own. But if you are not confident in your abilities, it does not matter either, deal with it without difficulty.

• First - there is no contact where it should be.
• The second - there is a contact where it should not be.
• The third is exceeding the permissible load.

As a special case of the first malfunction, one can consider a break, a broken contact in the wiring. The second case is characterized by a short circuit in the wiring. In the third case, it will be the high power of household electrical appliances not designed for your wiring.

Figure 1. The most common causes of electrical wiring failure.

1. Melting of contacts on the circuit breaker.
2. Melting of contacts in a socket or switch.
3. Reflow of contacts in junction boxes.
4. There is no contact in the cartridge or in the twist, or in the terminal block of the chandelier.

There are also completely anecdotal cases when, in order to eliminate a wiring malfunction, it is enough just to tighten the cork fuses more tightly or turn off unnecessary electrical appliances that cause group machines to turn off. But let's look at all this in more detail.

Sometimes the circuit breakers in the shield turn off not at all due to a fault in the wiring, but due to a short circuit in household electrical appliances. For example, it happens that the plug at the kettle closes or a wire is transferred somewhere. In order to exclude this option and not to sin on the electrical wiring, it is necessary to turn off electrical appliances that are suspicious and try to turn on the machine. If the machine turns on and the voltage appears, it means that it is not the wiring, but some electrical appliances are faulty.

Over my many years of experience, I have developed a certain methodology, which I will now tell you about. You need to start looking for a malfunction with the causes that most often occur in home electrical wiring. And also start with a simple one and move on to a more complex one by the method of elimination.

Figure 2. The sequence of actions when troubleshooting the electrical wiring of the apartment.

First of all, when there is a power outage, it is necessary to check the presence of voltage in the apartment electrical panel. If there is no voltage on the neighbors on the floor, then the problem is not on your side. If there is voltage, you need to pay attention to the group circuit breakers and their contacts, they should not be melted. If there are disconnected machines, it means that somewhere in the apartment there was a short circuit, or it was exceeded. permissible load. If all circuit breakers are on, but there is no voltage in the apartment, then you need to look for an open or poor contact.

The next step is to go to the apartment and turn off household electrical appliances that are left without voltage (pull out the plug from the socket), because the place of the short circuit can be in them, and not in the wiring. We are trying to turn on the machine, if it turned on, then the reason really was in one of the electrical appliances. If not, we keep looking. We unscrew all the bulbs and inspect the cartridges for a short circuit. If nothing is found, then we disconnect all the chandeliers and lamps from the terminal blocks. Trying to turn on the machine. Turning off? Looking for more!

The specific location of a malfunction, both an open and a short circuit, can often be detected by visual inspection of the wiring. At the same time, it is first of all necessary to pay attention to the places where the wires are connected and the connections of switches and sockets. We remove sockets and switches, turning Special attention on the wires that come out of the wall. Often the cause of the malfunction can be found there. It happens that wires, especially aluminum ones, break and close from old age, or they simply break. Darkening and charring of the insulation, melting and bare wires indicate local heating of the wire due to poor contact.

Figure 3. The wire on the socket contact has burnt out. Short circuit in the chandelier socket.

If the above methods did not help to detect a malfunction in the electrical wiring of the apartment, a short circuit, or a break, then it is necessary to inspect the junction boxes. These boxes are usually 15 cm down from ceiling level. You can find them under the wallpaper by tapping the wall in the intended locations. After opening the box, you need to inspect the contacts. Charred contacts can indicate both an open and a short circuit. If we are looking for a break, check for voltage in the boxes. This can be done with a simple test lamp. Anyone who has ever held a screwdriver in their hands is not at all difficult to make such a lamp from improvised materials. Moreover, you will need quite a bit, an old electric cartridge, a 220-volt light bulb and two pieces of wire, 30-40 centimeters each. But it is better and safer to use a special indicator, tester, multimeter. Like the picture below.

The task is getting harder! If the fault cannot be detected, it remains to check the integrity of each wire. In this case, it is imperative to de-energize the line by turning off the circuit breakers or unscrewing the plugs. So, we check the integrity of each wire. To do this, we will need to separate all the wires in the box, but before that, we must mark them so that after identifying the damaged wire, we can twist them as they were. Next, you will need to "ring out" each wire, that is, find out its direction, to which outlet it goes or to which lamp, switch. After that, you can measure the insulation resistance of each wire with a megger, it will show which wire is damaged. Some electricians do it the other way. Voltage is applied in turn, to each wire through a 1A machine and check whether voltage has come to the other end of the wire. In the event of a short circuit on this wire, the machine turns off, also indicating the damaged area.

After you find a damaged wire, you need to replace it. You can simply pull the damaged wire out of the scrub and clean it, and then fix the new wire in it. Connect the wires in the box as they were connected. But in most cases, it rarely comes to checking the wires; usually, a fault in the electrical wiring of an apartment can be found by doing the first 2, 3 steps from this article. In 100% of cases, with the help of these actions, it is possible to identify and eliminate the wiring malfunction.

Figure 4. At the end of the work, we measure the voltage in the network.

In any case, when working, you should not forget about safety precautions. That's all. I hope that this article will be useful to someone and will help in practice to solve real problems. And let your sockets always have 220V!

Work on the organization of electrical wiring can be divided into three types. The first of these is the replacement of electrical wiring. It is the most complex and labor intensive. Similar installation work usually carried out with a fairly serious repair of the apartment. Complete wiring replacement is the most effective method eliminate the shortcomings of the old apartment power system. But it is worth noting that it is not always applicable. The main reasons for this are the high cost of materials and the physical impossibility of overhauling the premises. How to be in such a case? Most electrical wiring problems can be solved with a partial system repair. This type of repair will be discussed in this article.

So, where does the repair of the old electrical wiring begin? First of all, you need to diagnose the system and understand which part of the power supply needs to be repaired. This issue does not require professional skills. If, when most household appliances are turned on at the same time, the introductory machine turns off, or plugs “fly out”, this means that the wiring is outdated and does not meet the needs of users. The same diagnosis follows from a short circuit in the outlet, as a result of which it turned black.

Determine the type of wiring

Important! Before performing work related to electricity, you must first turn off the power supply of the apartment.

Let's move on to determining the place where electricity enters the apartment. Depending on the type of house, several options are possible:

• switchboard on the floor;
• separate switchboard;
• apartment shield;
• a combination of apartment and floor shields.

First you need to open the floor switchboard and find the safety switches that are responsible for your apartment. We find a device that turns off all the power to the system - this is an input device. It is of two types:

• automatic protection - located on the left side in a row of automatic machines in your apartment;
• knife switch - located separately from the machines, above or below.

There are also other options.

The input device is replaced only when the entrance is completely or partially disconnected from the power supply. This can only be done by an employee of the operating company. But you can look at the face value of the machine and write down its parameters.

Let's move on. We look at how many circuit breakers are installed for your apartment. At least there should be several of them, and if with electric stove, then three. One machine is responsible for lighting, and the second for sockets.

If there are more machines on the switchboard, then you need to figure out what they are responsible for. Circuit breakers are designed to maintain the integrity of electrical wiring during a short circuit, power surge, as well as for simple communication - turning off and turning on the power.

You can check the area of ​​responsibility of the machines experimentally: by turning on the lights and lighting into the socket and by simply turning off the machines to determine the ratio of the "consumer group-knife switch". At the same time, in the process of such diagnostics, it is not necessary to use complex and expensive Appliances, as they can break if the machine is suddenly triggered.

We analyze the situation and move on to the next stage. After such a simple diagnosis, you will know how your electrical wiring works. Approximately it will look like this:

Stages of repair work

Having a diagram of the old power supply system of the apartment, you can start repair work. The following tips are recommendations and should be adjusted according to the individual case.

Replacement of introductory machines

First of all, it is worth replacing the introductory machine and protective group machines. Since there will be no full replacement of the old wiring, the structure of the organization of the work of protective devices will remain. In this case, it is not recommended to significantly increase the nominal value of the machines. For example, a 16 Amp protective device is installed on a group of outlets in an apartment. There is no need to change it to a 40 ampere automatic machine, this will not solve the problem of automatic operation, but it will create new problems - possible burnout of contacts or even a fire. If you have a 10 amp lighting machine, then it is better to change it to a new one of the same rating. For an outlet, the increase should be up to 10 positions, for example, it was 10 Amps, but it became 20.

The rating of the automatic protection device is selected taking into account the planned load on a certain part of the system. In accordance with GOST R.51628-2000, the part of the network that is controlled by one switch is called a group circuit.

Depending on the future load, the cross section of the wires is also selected. Based on the fact that the wiring remains the same, the relationship between the planned load, wire size and protective devices remains the same. Let's say that in your apartment the group network is connected to a 16 Amp machine, the wiring is organized with aluminum wires with a cross section of 2.5 square millimeter and is designed for a power of 2.5 kilowatts. Increasing the nominal value of the machine to 25 amperes, you still will not be able to turn on devices with a power of 4.5 kilowatts. The circuit breaker will keep the network, but the wires will heat up. Detailed information on the dependence of the cross section of wires on power can be found on the Internet.

A thoughtless increase in the rating of automatic protection devices will not solve the problem of congestion in the group circuit of the network.

Planning additional group chains

When repairing apartment wiring, one cannot do without organizing additional group circuits. For example, you can lay an additional circuit for powerful kitchen appliances or office equipment. To do this, you need to conduct from the switchboard on the floor electrical cables to the right places. Such a solution will unload the group circuits of the old wiring and avoid triggering the machines. In addition, an additional circuit will allow you to properly ground office equipment.

New circuits for grounding are laid with electric three-core cables - zero, ground and phase. The grounding conductor is connected on the floor board, where there is a grounding bus.

Additional circuits must be connected to a separate protective device. The optimal value of the machine in this case is 25 Amperes. If new chains will fit open way, then you can use copper cables with a cross section of 2.5 square millimeters and a 30 Amp automatic machine.

Having decided on the group circuits, you can do the aesthetics of repairing electrical wiring.

Laying new wiring

When laying new groups, you will most likely have to use the open method, which is not quite presentable, so the wiring needs to be given an aesthetic appearance. To do this, the cables must be laid in a special electrical box. There is a wide selection of different boxes on the market, so choosing the right one for the design is not difficult.

When organizing a group circuit, try not to rely on tees, install single blocks. The number of outlets in one block is selected depending on the needs: 5 outlets are enough in the workplace, and 3-4 in the kitchen.

Don't forget the zones high humidity- bathroom and toilet. Repair of old wiring should also touch it.

Electrical wiring in the bathroom

If your bathroom has a washing machine or other powerful consumer of electricity, then you need to run a separate outlet there, directly from the floor or apartment switchboard.

First of all, you need to ground the outlet, and after the circuit breakers, install a residual current device that protects against damage during current leakage. The operating rating of the RCD should exceed the rating of the machine, and the rating for operation, on the contrary, should be less.

The repair is completed with the replacement of old sockets and switches.

Replacement of switches and sockets

First of all, you need to remove the old outlet, then evaluate the quality of the insulation. If in doubt about their integrity, cambric - polyvinyl tubes should be put on the wires. If the outlet does not hold well in the wall, then new sockets must be installed. They are not expensive, but they will give the design reliability. Alabaster is used to fasten the sockets.

On this, in fact, the repair of the old electrical wiring in the apartment is completed. Let's summarize.

The quality of the repair depends on the following works:

1. Replacement of circuit breakers and introductory machine with similar new devices.

2. Organization of additional group chains. This will unload the system and improve grounding.

3. When installing sockets in areas with high humidity, RCD should be used.

4.Replacement of old sockets and switches.

5.Updating terminal connections, improving the fastening of socket boxes, or installing new ones.

The digital calculations given in the article are intended for wiring with a standard scheme grounding TN-C-S and power supply at 220 volts.

Dependences of current strength, voltage and wire cross-section

Dependence of cable thickness(S), voltage and current(I) for copper cable:

• S=1.5 mm, I=19 A;
• S=2.5 mm, I=27 A;
• S=4mm, I=38A;
• S=6mm, I=46A;
• S=10mm, I=70A;
• S=16mm, I=85A;
• S=25mm, I=115A;
• S=35mm, I=135A;
• S=50mm, I=175A;
• S=70mm, I=215A;
• S=95mm, I=260A;
• S=120mm, I=300A.

• S=1.5mm, I=15A;
• S=2.5mm, I=25A;
• S=4mm, I=30A;
• S=6mm, I=40A;
• S=10mm, I=50A;
• S=25mm, I=90A;
• S=35mm, I=115A;
• S=50mm, I=145A.

Dependence of cable thickness(S), voltage and current strength(I) for aluminum cable:

• S=2.5mm, I=20A;
• S=4mm, I=28A;
• S=6mm, I=36A;
• S=10mm, I=50A;
• S=16mm, I=60A;
• S=25mm, I=85A;
• S=35mm, I=100A;
• S=50mm, I=135A;
• S=70mm, I=165A.

• S=2.5mm, I=19A;
• S=4mm, I=30A;
• S=6mm, I=39A;
• S=10mm, I=55A;
• S=25mm, I=70A;
• S=35mm, I=85A;
• S=50mm, I=110A;
• S=70mm, I=140A.

The size of the cable cross-section in all countries is standardized, while the standards of the European Union in this part coincide with the norms adopted in the CIS countries. In our country, the document that regulates this issue is the "Electrical Installation Rules" or briefly - PUE.

Electricity is dangerous and can kill or injure. Work under stress on injuries is comparable to mine clearance. Even experienced electricians with great experience get electrocuted and die.

Therefore, do not rush to correct the malfunctions that occur in the current electrical circuit, and if you have no idea what and how to do in the electrical wiring, then do not take it. Better turn to professionals.

The article is intended for home master, representing the danger of electric current and having elementary skills in working with electricity. The article will help in troubleshooting electrical wiring in the apartment.

Tool for the job

Electric current passes very well through our body. Its power of 50 mA (0.05 A) is enough for lethal outcome under certain circumstances. Therefore, all tools used for work must block the path of electric current.

The handles of screwdrivers, pliers and other electrician's devices are made of dielectric materials, and shoes with clothes should protect exposed areas of the body from accidental contact with live parts.

Electrical voltage cannot be seen, smelled or heard. Its presence can only be determined by measurements with safe devices - a voltmeter or indicators designed to work with specific electrical installations.

It means that measuring device for phase voltage 220 V cannot be used in linear circuits of 380 volts and above.

In everyday life, a Chinese-made indicator screwdriver with a neon light is often used, an analogue of the industrial model UNN-1. The device has a bare metal tip for touching the current-carrying part and a dielectric case with a contact pad on the opposite side.

A neon lamp and a current-limiting resistor are mounted between the contacts inside the case. The operation of the device is based on the principle of passing an active current of a very small (safe) value through the human body.

There is a common belief among people that you can check the voltage with a test lamp, which is equipped with tips and protected by a screen with a grid. Safety rules categorically prohibit its use: a glass bulb explodes when connected by mistake, and flying glass caused harm a huge number of people.

Troubleshooting electrical wiring. Beginning of work

When only you lost the light, and the neighbor has it, then you need to determine the location of the damage. Open the apartment or floor (in old houses) switchboard and check the position of the protective devices and circuit breakers, the condition of the fuses. They can shut down when overloaded.

But if voltage comes to the switchboard, the circuit breakers and protections are turned on, but there is no light, then you need to look for the cause of the malfunction in the wiring.

This is done by measurements. It is convenient to work with an indicator, but first check that its neon bulb lights up when it touches a live part that is obviously energized.

The indicator is applied to the phase wire at the entrance to the apartment to the meter. If voltage comes, then check its presence at the output of each switched on machine and protection. So we will make sure that the circuit breakers are working.

Attention! Two wires are used to carry electric current. Do not forget about the possibility of a zero break. It comes directly and can only be broken by a packet switch or an introductory machine just once. And then to the meter: so that the energy supervisor can safely change metering devices. Further, all neutral wires are assembled on a common terminal block through junction boxes.

The integrity of the neutral wire can be determined by measuring the voltage with a voltmeter between it and the live phase wire. If there is no voltmeter, then do not use a test lamp (I am focusing my attention for the second time). In extreme cases, briefly connect an electric shaver or fan.

There is ground potential on the neutral wire: the indicator light will not light.

Causes of defects in electrical wiring

Electric current stops flowing when the circuit is broken, which is created by wires or switching devices.

Therefore, start troubleshooting by checking the switches, switches, protective devices located in the apartment. Pay attention to the position of the RCD and difavtomatov. They react to the appearance of leakage currents that flow from the phase wire to the ground through insulation faults, bypassing the neutral wire.

You can not coarsen their settings or block, as negligent electricians do. When the protection is triggered, it is important to find the place of damage.

Therefore, we distinguish two types of defects:

breakage (burning out) of the conductor;

insulation failure in the circuit.

Violations of electrical contacts and integrity of wires

Troubleshooting should be carried out when relieved stress from the scheme, checking its absence and excluding the possibility of submission by unauthorized persons.

First you need to decide on a possible installation scheme, conductor routes. They can be laid:

• radially: all cables exit from the protection of the apartment shield and are laid directly to their consumers;
• tires: phase, zero and PE conductor are bred from the switchboard to the junction boxes of the rooms. Consumers are powered by them;
• in a circular way: the wires come out of the apartment shield to one consumer and are bred from it to another, and then the third and the rest follow in a circle;
• combined method (random sequence).

Each conductor is designed for a certain load. When it is exceeded, intense heat generation begins, which can not only break the insulation, but burn the metal of the conductor.

Suffer from an increase in load, first of all, places with increased electrical resistance, which occurs:

• from loose contact connections (bad twists, loose screw terminals, loose spring clips, etc.);
• when the metal is deformed during installation or operation individual places conductors (cuts, scratches, cracks, clamping of mounting pads by screws, wire breaks from multiple bends);
• in cases of incorrectly selected conductors according to the current load;
• when the mechanisms of switching devices are worn out.

Switching and switching devices, when the load current is interrupted, perceive a spark discharge, which constantly acts on the contacts, oxidizes them and each time worsens the electrical resistance.

All of the listed problem areas should be carefully examined. It may be difficult to access junction boxes covered with wallpaper or building structures, wire connections hidden in strobes. When dismantling such places, you should inform the owner of the apartment about the need to open the wiring.

Insulation violations

The current flows through the metal of the wire, the insulating layer of which eliminates leakage, ensures a strict direction of the movement of electrons. The dielectric properties of such materials depend on many factors:

• temperature of the working environment;
• mechanical influences;
• electrical loads;
• irradiation with light rays.

The photo shows the destruction of PVC insulation copper wire not protected from sunlight. At first, small cracks that appeared gradually developed into large bare metal areas. Such places create not only leakage currents, but serious short circuits.

Overload electrical wires(even minor ones) heat the insulation above acceptable limits. As a result, its elasticity and dielectric properties are violated. Wiring can become a fire hazard in a very short time.

When inspecting the circuit, be sure to analyze the quality of the insulation.

To keep your electrical wiring working reliably:

• Entrust work in electrical wiring only to qualified specialists.
• Create a load on the electrical circuit no higher than the design power.
• Carefully analyze the facts of disconnection of voltage by protective devices and always keep them in working order.
• Carry out preventive inspections and work in a timely manner.

Even perfectly executed new electrical wiring, with inept operation, can quickly fail, and skillful people use the capabilities of the old circuit for a long time without accidents and fires.