What is dialing and how to correctly dial wires, cables and various electrical equipment

If the task is to check the electrical circuit for breaks (leaks), then you need to familiarize yourself with how to test the wires with a multimeter. A specialized measuring device is indispensable when testing wiring. And even if you are not a professional electrician, once you understand the basic rules for safe use of a multimeter, you can easily identify problem areas in your home electrical network.

Setting up and preparing the multimeter

To use the multimeter correctly, you need to configure it. This means that you need to select the value to be measured and the limit of its operation, that is, the value beyond which it will not go.

Symbols on the front panel of the meter

A multimeter can be used to check various electrical quantities: current, voltage, resistance, frequency. It is also used to test the performance of various radio elements: resistors, capacitors, diodes and transistors. The very part of the word “multiple” implies the presence of several types of measurements. To select these types, there is a knob on the front panel of the tester, by turning which you can select the required value.

In most cases, the symbols depicted on the body of the multimeter represent designations of electrical quantities accepted in physics or conventional graphic designations of radioelements intended for testing. On the front panel you can find the following symbols:

• U - voltage symbol;
• V - stands for volts, this is also a measure of voltage;
• I is the current; when you set the knob to this designation, the current strength will be measured;
• A - amperes, a measure of current strength;
• Ω, R - symbol of resistance;
• Ohm is a measure of resistance, Ohms;
• -| |- - this icon indicates a capacitor, the multimeter will measure its capacitance;
• Diodes and transistors are also marked on the tester body with their symbols.

But not only the measured values ​​are indicated on the front panel of the tester: the holes for connecting the probes also have their own designations. One of the meter slots will always be occupied by the black probe. This is a common hole, it is usually marked with the inscription COM, which means “common”. In addition to it, the multimeter has two or three working holes, designed respectively for measuring voltage, low current and high current.

The socket marked U, Ω, Hz is intended for measuring resistance, voltage and frequency, as well as for testing various radio elements. You also need to install a probe here to test wires and cables for breaks.

https://youtube.com/watch?v=DU1hvRCR2Rw

The hole marked mA (mA) is used to test low currents (up to 1 ampere), and the hole marked A (10 A) is needed to measure high amperages.

Limits of measured values

In addition to designations of the values ​​of the parameters being tested, designations of measurement limits are printed on the front panel of the multimeter. In more advanced equipment, these inscriptions are not present, since the tester electronics itself selects the limit based on the signal supplied to it at the input. However, most multimeters require manual adjustment of measurement limits.

Typically, limits are given by numbers that are multiples of 2: 2, 20, 200... Thus, when choosing a limit, you should be guided by the rule: choose a limit higher than the one being measured, but of the same order. For example, to measure the voltage in a home electrical network (in an outlet), you need to select the AC voltage measurement mode and the measurement limit of 2000 volts. And to test the wires with a multimeter, you need to select the resistance mode and the minimum measurement limit of 2 ohms. However, long cables require a higher measurement limit of 20 ohms. Additionally, you can turn on the button with a sound signal that sounds when a short circuit occurs (circuit presence).

Connecting the tester

To check the parameters of electrical circuits and the continuity of wires and cables with a multimeter, you must correctly connect the meter to the circuit being tested. When checking for circuit integrity, the required area between the meter leads is checked. Therefore, the tester is connected to the terminals of the circuit. If voltage is being measured, the multimeter must be connected in parallel to the section where the voltage is being tested.

When measuring current, the multimeter must be connected in series to the open circuit of the circuit being tested, for example, between the power supply terminal and the load terminal.

Detailed instructions and sequence of actions

To perform the check you must:

1. Turn on the multimeter and select the required mode (ringing or ohmmeter). If the symbol in the form of a battery icon lights up on the device screen, you should install a new battery. To turn on the device, simply turn the mode switch from the Off position or press the button on the side of the case.
2. Install probes whose insulation is not allowed to break.
3. Proceed with testing, taking into account the characteristics of the electrical wiring. Bare areas are cleaned of contaminants or oxides, since deposits do not conduct current and do not allow correctly checking the integrity of the line.

Continuity of a long conductor

To check a long single cable:

1. Determine the length of the line and purchase a thin wire of the appropriate size.
2. Strip the ends and connect with a screw or spring terminal.
3. Connect the probes to opposite terminals. An audible signal indicates that the cable is working properly.

Testing wires with a multimeter

Manufacturers make different types of multimeters, but the measurement principle remains the same, only the location of the controls and measurement limits differ. To check the integrity of the wires, the measurement mode switch is placed in the continuity position; this is marked with a diode or buzzer sign. After which the dialing process is carried out using the methods described above. The integrity of the conductor, in addition to the display of zeros (no resistance), is accompanied by an audible signal or an LED indicator, this depends on the brand of the multimeter. article: → “How to use a multimeter for dummies?”

Multimeter GE 2524 in dial position

The probe with the black wire is inserted into the connector with the ground symbol (case), the red one above, into the connector for measuring resistance with the Ohm symbol “Ω”. The disadvantage of many digital multimeters in dial mode is the delay in the sound indicator signal when touching the contacts. It is necessary to fix the probes on the wire for 2-3 seconds to make sure there is contact. This inertia in operation creates some difficulties in checking the integrity of the wire.

Multimeters of the UNI-T type have good performance in dialing mode; the sound indicator operates almost instantly when the contacts are closed.

In other parameters, UNI-T is not inferior to other models in measurement accuracy and number of options. article: → “Checking circuits with a multimeter or tester.”

Comparison table of characteristics of Fluke-179 and UNI-T UN61 multimeters

Please note that for all instruments it is advisable to use probes with gold-plated rods. Unlike steel ones, they are not subject to oxidation and provide reliable electrical contact.

How can you ring the wires?

There are quite a large number of diagnostic equipment options for checking the integrity of electrical circuits and identifying short circuits. Such devices include:

• various testers: there are a wide variety of testers on the market for electrical networks and communication lines, from simple ones made in China to expensive ones from European manufacturers;
• homemade testers: based on an autonomous power source (rechargeable battery) and a test lamp;

• multimeters: multifunctional devices for measuring network characteristics and diagnosing its performance;

Program for checking access to the Internet Network Traffic Monitor

Search engines often search for the answer to the question: “a program for testing twisted pair cables.” A computer with Windows installed already has a program that displays the message “The network cable is not connected” if the twisted pairs in the cable are broken or shorted. You will have to look for the location of the break or short circuit yourself; there is no program that would indicate the exact location and cause of the malfunction. There are special testers for this, for example MicroScanner Pro.

It’s another matter if there is a connection to the Internet, but it is unstable or the download speed has suddenly dropped. To monitor network traffic, there is an excellent free program, or rather a utility called Network Traffic Monitor.

It allows you to measure data transfer speed in real time, observe changes in speed over time, save data on a hard drive, rubber windows, extensive customization options and many other useful services. Supports many languages, including Russian.

Installing the program on your computer is simple, just run the EXE file and press the confirm button several times. Network will automatically be added to startup and will monitor and save all data. To display any of the windows on the monitor screen, just right-click on the tray icon and select the desired window. Network Traffic Monitor is the best utility for analyzing and diagnosing network quality that I came across during my search. I have tested the functionality of the Network Traffic Monitor program with Windows HP and Windows 7. You can use the Network Traffic Monitor program with one click of the mouse from my website.

Causes of malfunctions in car wiring

A vehicle's electrical system has primary charging circuits for starting and charging the battery, as well as additional circuits such as electric lights, electric motors, sensors, magnetic locks, a stereo system, and a computer. All circuits are opened and closed by switches or relays (remote switches controlled by electromagnets).

Current in the circuit flows through one battery cable, through a live component, and into the battery through the metal body of the vehicle. The housing is connected to the battery ground terminal with a thick cable.

In a negative (-) grounding system, current flows from the positive (+) terminal to the operating component. A vehicle body ground component that connects to the negative (-) terminal of the battery.

In practice, there are quite a few probable causes of failure of automotive wiring. Here are the most common reasons for leaving them:

1. The aging process that results in brittleness, cracking, and eventual failure of insulating materials. This exposes the wires in the car and creates the risk of a short circuit, which can lead to a fire in the car.
2. A wire has been installed that is not suitable for the power and operating conditions in the vehicle, is not mechanically resistant enough to wear or abrasion, or is chemically unstable to environmental conditions.
3. Mechanical failure due to shock or vibration.
4. Moisture penetration into insulation causes serious problems, including short circuits and corrosion of copper wires.
5. Overheating of electrical cables leads to deterioration in the quality of the insulating material of the outer sheath, as well as to premature failure of the cables.
6. Electrical overload.
7. Rodent damage.

Safety rules when making calls

Any electrical work, including diagnostics of conductors, requires compliance with all precautions and electrical safety rules. The main rules, the observance of which will save your life and health, are as follows:

Always operate with power off. Post a sign that says “DO NOT TURN ON”

PEOPLE WORK!” at a switch or machine; Do not touch exposed conductors with bare hands, use special clothing and special tools; Use power tools with sharp edges carefully: use gloves and do not damage the cord; At the end of the work, all faulty systems must be de-energized, and exposed wires must be properly insulated.

Take care of yourself and remember, if you doubt that you are capable of working with electrical networks, entrust this task to professionals.

How to check wiring correctly

Electrical wiring is checked in order to identify faults, make a decision on further operation during repair work in the building, and also to obtain information about the condition of the wiring after emergency situations. Such situations include flooding of the premises or the activation of protective devices when there are no problems for consumers. In apartments and private houses, it is necessary to check the wiring immediately after purchasing the premises, if it was previously operated by other persons.

Dialing methods

There are several ways to ring wires at home:

Using a light bulb and battery. This is the simplest and fastest method. In order to construct such a device, you need to have a light bulb and a battery (several batteries can be connected together), as well as connecting conductors and a probe. In addition, do not forget that the voltage of the light bulb and the battery should be the same, or the battery should have more, but not vice versa. The connecting wire must be long enough to ring the wire from a distance.

In order for the dialer to work correctly, it is necessary to mark the cable in any order. The operating method of such a device is as follows: a wire that comes from the battery is connected to one core, and a light bulb is attached to the probe. Use this probe to touch the conductors at the opposite end of the cable one by one. If the light comes on, it means this wire is connected to the battery.

You can learn how to ring the wires of a light bulb and a battery from this video lesson:

Using a multimeter. This device measures various parameters of the electrical network (for example, voltage, current, resistance). In the house, such a device will be indispensable if you need to check an outlet or switch, check for a break, or find out where the wire goes.

You can test the cable with a multimeter using the following method:

1. The dialing function is installed. Depending on which model of device is used, this mode is designated differently. As a rule, it is indicated by a diode.
2. Then you need to find the phase in the distribution box. This is done as follows: you need to turn on the power and use an indicator screwdriver to check each cable. We mark the one we need with tape or tape and then determine zero.
3. After this, you should find the voltage. To do this, set the multimeter to the “voltage measurement” mode. Using a probe, we check each wire. If the next time you touch the probe, it lights up around 220 V, then the right one has been found.

To check the electrical wiring in the wall for integrity, you need to disconnect the cable from the power source. Set the multimeter to resistance measurement mode. When the probes are closed, zeros should appear on the screen.

The video below clearly demonstrates the technology of testing a cable with a multimeter:

These two methods are convenient if the dialing is carried out over a short distance and can be done by one person. If the cable is long and its ends are in different rooms in the apartment or outside, then use a different method.

Using telephone handsets. Dialing with telephone headsets is carried out as follows: the capsules in the handset are connected to each other and a battery is connected to them, the voltage of which does not exceed two volts. Thanks to this technique, workers can talk to each other over the phone and coordinate their actions.

Cable wiring diagram using telephone handsets:

You can ring as follows: the cable on one side is connected to the tube conductor, and the other conductor is connected to any core. On the other hand, the cable connects to the tube conductor, and the other to each core in turn. If workers can hear each other on the handset, it means they are connected to the same conductor.

You can see the entire technology of work in this video example:

Using a transformer. There is another way in which you can ring cable lines - this is ringing using a transformer, which has several taps coming from the secondary winding. The technique is as follows: the beginning of the winding is connected to the grounded shell of the conductor, and the transformer taps are connected to the cores and power each of them. If you measure the voltage that exists between the shell at the other end and the conductors, you can determine whether the end belongs to a specific conductor. The dialer will allow you to identify and mark the necessary cores. You can learn how to correctly mark wires from our article.

Old housing

It is more difficult to check the condition of the electrical wiring in an old house or apartment, especially if you have just bought a home and have no idea how the electrical wiring is done in the rooms. So, an audit of the electrical network must be performed using the following method.

Find all distribution boxes by room

By opening the cover, you can understand which cable is used for the hidden electrical wiring: aluminum or copper, as well as what cross-section of the wires. You should also immediately check the condition of the insulation - if the wiring is old, even the slightest bend in the cable will cause the insulating layer to begin to crumble or crack. Such electrical wiring must be changed without any reservations.

It would be correct to check the insulation resistance with a megger (so to speak, for breakdown and current leakage). Its resistance must be at least 0.5 MOhm. But not everyone has such a device, so “for the sake of decency” you can at least measure the resistance with a multimeter, although this can hardly be called a normal test. If the insulation resistance is poor, leaks will occur and the RCD may trip if you upgrade the electrical panel. It is equally important to immediately inspect all wire connections - there should be no damage or twists, especially aluminum and copper.

If necessary, you should immediately connect the wires with terminal blocks instead of twisting them. We talked in detail about how to find a junction box in the wall of an apartment building in the corresponding article.

Check sockets and light switches

In sockets, it is necessary to inspect the integrity of the wires and insulation, and also determine the rating for which they are designed. If three-wire wiring is connected to the sockets, it is imperative to determine where the phase is, where the zero is and where the ground is. To do this, you will need a multimeter or an indicator screwdriver, and we provided the technology for determining phase and zero in the corresponding article.

Cable testing devices

To test wiring, there are several devices that can help you complete the task.

There are devices of the E-121 series, popularly called Woodpecker. Using this device, you can determine the location of a hidden wiring break. Testing a power line using Woodpecker is very easy. In this case, it is necessary to guide the tool along the wall along the electrical network. If the Woodpecker made a sound signal, there is a break in this place.

Testers are able to determine the integrity of the cable, as well as the correctness of its connection. Some types of more expensive testers have a built-in multiplexer, as well as an analog-to-digital converter.

Tone generators are used to test cables. These types can more accurately determine the location of the break and determine the location of hidden wiring. In this case, the generator operates in a de-energized network, otherwise the device may fail.

The device is capable of testing various types of cables: from multi-core power cables to thin radio wires. However, tone generators cannot determine whether electrical connections are correct.

You can also ring an electrical circuit using telephone handsets or a transformer.

Timing for replacement of electrical wiring

After the electrical wiring has reached the end of its service life, it needs to be completely replaced without testing or inspection. The timing of inspection, replacement or interval between major repairs is established by VSN 58-88(r) (departmental building codes) and is:

• for hidden indoor networks 40 years;
• for open 25 years;
• for main wiring between apartments and input and distribution devices 20 years;
• for production and technical premises and lighting of public places 10 years.

Checking the electrical wiring in an apartment or private house, despite its apparent complexity, if you have the necessary knowledge and a minimum set of tools, you can do it yourself, without inviting a qualified electrician.

We check the wiring in the apartment with a multimeter

Let's take as an example a modern apartment in which the wiring is done in accordance with current requirements and standards. This means that when laying the lighting lines and power outlets, they were separated, and separate wires were laid for them in each of the rooms. Each of these circuits is powered from the apartment panel through a separate circuit breaker.

If the light has gone out in one of the rooms, you should first check that the lamp is working properly. Before starting work, it is necessary to turn off the power to the room/apartment depending on the power supply. When using an opaque incandescent lamp in a lamp, the integrity of the filament is difficult to visually determine, so you will need a multimeter and its continuity function. Let's figure out step by step how to do this correctly.

First you need to check the shield for triggered circuit breakers. In the first case, they will be in the on position (then the fault may be hidden in the room switch, lamp or socket). The likelihood of damage to the wiring in such a situation is low. If the device works, you will need to check everything except the room switch, including the switchboard itself.

If the machines don't work

1. Make sure there is voltage at the input and output of the machine. If it is, you can proceed to further verification.
2. Prepare the device for operation and check its serviceability by short-circuiting the measuring leads.
3. Unscrew the lamp from the socket.
4. Touch one of the measuring probes to the base (the metal part of the lamp with threads), and the second to the central contact of the lamp (the insulated center of the end part of the base).
5. A sound signal and instrument readings that are different from 0 or 1 mean that the lamp is working. If it is faulty, you need to replace it, which will solve the problem.
6. We check the cartridge for serviceability. To do this, you need to disassemble the lamp, make sure that the connected wires and contacts are intact. If everything is in order, then the cause of the failure is not in the cartridge. If malfunctions are detected, they must be eliminated. The lamp cannot be screwed in yet.
7. We check the serviceability of the room switch. To do this, remove the plastic cover, unscrew the screws and take it out of the mounting box. We inspect the equipment for the appearance of carbon deposits and check the tightness of the fasteners. If everything is in order, you need to install the measuring ends of the tester on the contacts of the switch. The appearance of a sound signal when dialing in the on position will indicate that the equipment is working properly. The wires do not need to be disconnected.

During such a check, as a rule, a malfunction is identified, which becomes the cause of all the troubles. Eliminating it allows you to quickly solve the problem.

If the machine worked

To ensure electrical safety during work, in this case the voltage is turned off using a general apartment circuit breaker. Next, the serviceability of the socket and the wires connected to the lamp is determined according to the algorithm described above. If there are no faults, you need to check the wiring itself using a multimeter and the continuity function. Such malfunctions happen quite rarely, but they still happen, for example, when installing suspended ceilings or decorative interior elements.

The wiring in this case is performed as follows.

1. Using a screwdriver, disconnect the connected conductor (if installed correctly, it is located at the bottom) and move it to the side. The “zero” of this group is, as a rule, located at the zero clamp under the machines.
2. Unscrew the incandescent lamp from the socket. Using a ready-to-use tester, we check the line by connecting one of the measuring probes to “zero” and the other to the disconnected conductor. If the device beeps, it means the wiring is shorted.
3. In this case, in the room under the ceiling above the switch, we find and open the junction box. We disconnect the wires.
4. We check all groups of wires for short circuits. To determine the section of the circuit in which there is a short circuit, we again check the circuits on the apartment panel with a multimeter. If the signal sounds, it means that it is the wire laid from the switchboard to the box in the room that needs to be repaired. Otherwise, the search will need to be continued until a result is obtained.

New building

It is most often necessary to check the electrical wiring in a new building after installation after purchase, before major repairs - finishing the walls and arranging furniture. The importance of this event lies in the fact that if you do not inspect the cable line from the very beginning, in the future it will be much more difficult to check the wiring under a suspended ceiling or behind plasterboard sheets.

First of all, you must calculate the total power of the electrical appliances that you will use, based on which, calculate the cable cross-section by power and compare this value with the cross-section of the conductor already laid in the walls. If the cross-section is insufficient, be sure to replace the electrics, however, as experience shows, such problems do not arise in new buildings.

The next step is to check the condition of the hidden electrical wiring. The insulation must not be damaged, and all wire connections must be made using terminal blocks or other connectors (for example, PPE caps), but not by twisting. Twisting is prohibited; see the list of permitted connection methods in Chapter 2.1. PUE clause 2.1.21. It is also important to determine the cable cross-section and check the ratings of the sockets. The socket group must have copper conductors with a cross-section of at least 2.5 mm2, the rating of the circuit breaker of the socket groups must not be greater than the rated current of the sockets, usually 16A.

If all the above requirements are met, the last thing left to do is to check the wiring in the apartment for load. In other words, you need to check yourself whether the switchboard is assembled correctly. When all equipment is connected and all lamps in the rooms are turned on, the machines should not operate.

If a circuit breaker trips, it means the electrical wiring is not able to withstand the load from the connected electrical appliances, as a result of which it will be necessary to replace the circuit breakers, divide the electrical wiring into groups, etc. If the circuit breakers in the panel do not turn off after turning on the load, then the home wiring is correct. It wouldn’t hurt to additionally check the reliability of the connection of the machines in the panel, as well as checking the ratings with the load that comes to them.

In what cases is wire testing carried out?

This question can be answered in a few words - if the current-carrying core breaks or the integrity of its insulation is compromised.

Let’s clarify this answer and consider typical situations:

• Let's say an outlet or switch stops working. After you have made sure that the problem is not in the connections (including the junction box) and not in the light bulb (lamp), it is advisable to ring the wires in this area. If the integrity of the wiring is compromised, the multimeter will signal this.
• Developing the first example, it can be noted that such situations are not uncommon during repair work (drilling holes) and short circuits due to dilapidated wiring and network overloads.
• An atypical, but quite effective use of multimeter testing is to determine the required conductors on large sections of wiring. This method is appropriate when the color marking of the wires does not allow you to accurately identify the desired conductor.
• Also, in everyday life, dialing allows you to determine the integrity of electrical appliances (lamp, iron, switch, fuse). And if you are well versed in electronics, then when soldering, repairing printed circuit boards and other devices, testing circuits is a mandatory step.

Finding the location of a short circuit or broken wire

So, we already know how to test wires with a multimeter. All that remains is to learn how to determine whether a wire is broken or a short circuit in the wall. At the moment, there are special devices for determining the location of cliffs. But their price is quite high and, if you do not plan to earn money from this, such a purchase is not advisable.

• As we have already said, there are now many methods and devices for determining the location of a wire break. I will give an example of just one, which I have been using for many years and which has never let me down.

Capacitive voltage indicator "FLUKE"

• It only requires a capacitive voltage indicator. I use it, but this issue is not important. The main thing is that it works correctly, and not from the slightest movement. There are those too. Its cost is not so high, and it is quite a necessary thing in the household.
• To determine the location of a phase wire break, you simply move it from the distribution box, where there is voltage, along the wall along the intended location of the wire. As long as there is voltage on the wire, the indicator lights up. At the site of the break it will go out.
• To determine the location of the break in the neutral wire, you just need to briefly make it phase. To do this, first of all, we relieve tension. Then we disconnect the phase neutral and protective wires and connect the neutral wire to the supply phase wire. After applying voltage, we proceed in the same way as when searching for a broken phase wire. Don't forget to restore the schema after searching.
• If there is a short circuit with a break, then disconnect all wires except the phase wire, and then apply voltage. Then we proceed in the same way as when searching for the location of a broken phase wire.

Checking the electric heating element

You can also ring an electric water heating element with a multimeter. To do this, the probes of the device must be attached to the contact plates of the heating element. If the resistance reading is small, then the heating element is working. With very large values ​​or one (depending on the model), the heating element is damaged and requires replacement.

Note! Sometimes one housing may contain two heating elements connected to voltage in parallel. In this case, you need to ring them separately, having first removed the jumper between them

It is very important for boilers and other water heating devices to ring the contacts of the heating element for penetration into the body

To do this, the probe is connected to one of the contacts, and the second - to the body of the heating device

It is very important for boilers and other water heating devices to ring the contacts of the heating element for penetration into the body. To do this, the probe is connected to one of the contacts, and the second to the body of the heating device. If the tester shows a certain value, the internal insulation has been damaged in this heating element.

To prevent electric shock, the heating element must be replaced.

If the tester shows a certain value, the internal insulation has been damaged in this heating element. To prevent electric shock, the heating element must be replaced.

Initial inspection after purchase

If you just bought a house or apartment, the first thing you need to do is check the condition of the wiring, because... Even the slightest malfunction can subsequently lead to electric shock or fire. In a new and old house, the inspection technology will be different, so we’ll look at both methods separately. We immediately draw your attention to the fact that before checking the electrical wiring, it is necessary to turn off the electricity in the panel. Working under voltage, especially for inexperienced electricians, is strictly prohibited!

Cable phasing

Phasing is the ability to determine in what order the phases alternate when connected in parallel. This is necessary in order to avoid short circuits. Indeed, in order to increase the reliability of power supply, sometimes one conductor is not enough (or if the consumer’s power is too high). In order for the electrical installation to work normally, another wire is placed in parallel. In this case, it is necessary to take into account the phase rotation. The phasing diagram is shown below:

Phasing can be done in several ways: using a voltmeter or an incandescent lamp. A voltmeter is used for 380/220 V installations. The technique is as follows: cable 2 in the first installation is connected using a switch, and in the second, thanks to a voltmeter, it determines the voltage between the core and the bus to which it is planned to be connected.

If the voltage is linear, then the core and bus have unequal phases, so connecting them is prohibited. If the voltmeter displays zero, then this indicates that the wire and the bus have the same potential, respectively, they have the same phase and can be connected. Other conductors are tested using the same method.

If there is no voltmeter, then phasing can be done using two incandescent lamps that are connected in series and have a rated voltage of 220 volts. If the lamps do not light, then the wire and bus belong to the same phase.

You should also take into account the fact that after such actions a certain voltage remains on the cable cores, which is associated with a residual capacitive charge. Therefore, the cable should be discharged after the next passage of voltage. This is done by connecting the conductors to grounding.

So we looked at the main methods of testing wires and cables, as well as devices that can be used for such work. We hope the information provided was useful and interesting for you!

We also recommend reading:

• How to use a multimeter correctly
• What is phase rotation
• How to detect a short circuit

What you need to know about the multimeter

The model of the multimeter does not matter much, but it is desirable that it have a dialing function. The handle of the tool is installed on the dial. When connecting the probes and closing the working contacts, a sound signal will be heard. Such a signal is not required in the device. A break in a hidden or open electrical circuit will be signaled by a unit on the scale.

You can also check hidden wiring in the wall. If there is no damage, the tester will show resistance. In small household networks it should be closer to zero values.

Checking in the absence of testers

A multimeter and tester may not be at hand. In this case, you can use the manual verification method. To do this, you need to cut off pieces up to 15 cm long from each end of the cable. Next, you should remove the winding by 5 cm. And expose the cores by a couple of cm.

After this, prepare a container with water, which should be made of glass or plastic. Ordinary table salt weighing 1/4 of the weight of water is added to the liquid and mixed until completely dissolved. The cable cores are conductors and their contact must be avoided.

The other side of the cable section must be connected to a power source with a voltage of more than 3 Volts. A regular battery, a smartphone battery, and other safe sources may also work.

After applying voltage, you should monitor the wires in the water. The negative conductor should be covered with white bubbles, and the positive conductor should be covered with yellowish-green ones. If everything is so, then the twisted pair is in good condition and no short circuit has occurred. If there was a short circuit, then bubbles will come from the other vein.

Wiring and requirements for it

The first and very important point that you should know about before starting electrical installation work is that in panel houses (Khrushchev-era buildings) you most often cannot trench walls in accordance with Moscow Government Decree No. 73-PP dated February 8, 2005 “On the procedure for renovating premises in residential buildings on territory of the city of Moscow." Also, according to Government Decree No. 508 (Clause 11.3 and 11.11 of Appendix No. 1), it is prohibited to tap load-bearing walls.

In this case, it would be rational to conduct wiring through existing channels, the floor or under the ceiling (if a suspended or suspended ceiling is planned). The first and last options are more preferable. If the electrical wiring in the apartment is changing and you plan to cover the walls with plasterboard, an excellent solution would be to lay the wiring behind the plasterboard.

Important! It is strictly prohibited to scratch the ceiling in the apartment! The only option in which you can make grooves on the ceiling is to first apply an additional layer of plaster to the ceiling, in which the cable will be hidden. This layer can already be carefully grooved without touching the monolith. Those

The simplest option is to draw lines from the panel to sockets and switches along the ceiling, ducts or floor, and then make vertical grooves and so-called wells for installing socket boxes

Those. The simplest option is to draw lines from the panel to the sockets and switches along the ceiling, ducts or floor, and then make vertical grooves and so-called wells for installing socket boxes.

Another important point that you should pay attention to if you decide to do the wiring in the apartment yourself is that noisy work is allowed from 9 am to 7 pm (except Sundays), while an hour of silence must be provided from 1 pm to 3 pm! Shredding is a noisy job and can not only cause the anger of neighbors, but also cause a fine (from 1 to 5 thousand rubles for individuals). Let's return directly to the installation of apartment electrical wiring

As we said earlier, the length of the conductors must be purchased with a reserve. This reserve will be used for connecting them to each other (on each side the outer sheath of the cable is removed by 5-10 cm) and for connecting sockets, switches, lamps (length reserve from 10 to 15 cm)

Let's return directly to the installation of apartment electrical wiring. As we said earlier, the length of the conductors must be purchased with a reserve. This reserve will be used to connect them to each other (on each side the outer sheath of the cable is removed by 5-10 cm) and to connect sockets, switches, lamps (the length reserve is from 10 to 15 cm).

The video shows how to correctly install electrical wiring in an apartment without breaking the rules:

How to connect wires

Before measurements, it is important to strip the ends of the wires from insulation and remove oxide from the cable cores. The oxide on the wires may have high resistance, which will be higher than the value limit of the selected resistance mode of the device, which will give incorrect readings

Before making the call, you need to remove the mains voltage from the electrical wiring and remove the terminals from the battery in the car. If there are capacitors in the wire continuity circuit, then they need to be discharged by short-circuiting the terminals. All these precautions will help avoid damage to the multimeter and give more reliable results.

For convenience, when making calls, use special wire clips - “crocodiles”. The “crocodile” is put on the probe and clamped onto a section of the wire. The use of such clamps increases the convenience of working with wires, as your hands are freed.

Short cables and wires can be tapped at one end, while long wires must be thoroughly cleaned of oxides and twisted together on one side. Then the dialing process is carried out only on one side. You can ring the wires without a multimeter. For such purposes, electricians use a specially made “dialer” consisting of a battery and a light bulb. A sound generator and headphones are also used to check cables and wires.

Battery-powered bell with light bulb

How to identify problems

Wiring Diagram
Troubleshooting is easier if you have a basic wiring diagram. The plan is attached to the technical passport of the housing. If not, a drawing is drawn up - if the rules are followed, the routes run in a straight line (vertical, horizontal).

Regular testing with a multimeter will help identify problems. It is not difficult to determine in which area the breakdown occurs. For example, if the sockets and switches connected to the box do not work, the problem is here. If there is only one, there is a breakdown between the box and the socket.

Modern technologies and systematic checks will ensure safety during operation of electrical wiring in the apartment and increase service life. The main thing is to follow the principles and rules of work.

Checking electrical circuit parameters

When testing electrical circuits, you can test many of their parameters. This includes current, network voltage, and signal frequency. But to determine serviceability, you only need to ring the circuit for integrity and check the insulation resistance. Both can be done with a multimeter.

In order to know how to test electrical wiring with a multimeter, you need to correctly configure the measuring device and correctly perform the measurement steps. To check the integrity of the wire you need:

1. Connect the black probe of the multimeter to the socket labeled COM, and the red one to the socket labeled U, Ω, Hz;
2. The meter knob must be set to the 20 Ohm position;
3. Connect the measuring contacts to both ends of the wire. If the ends are in different places in the room, you need to use a previously tested extension wire;
4. The tester screen will display the value. If the value does not exceed 2 ohms, it means that the integrity of the wire is not compromised. If the readings are not at the same level or more than 8-10 ohms, then there is a break in the circuit.

In the same way, wires in a car and cables of various electronic devices are tested.

In addition to checking integrity, wires are tested for insulation resistance. This can also be done with a multimeter:

1. The probes remain in the same holes as when checking integrity;
2. The measurement mode selected is the same - resistance test;
3. The measurement limit must be selected as large as 20 or 200 megaohms;
4. Touch the probes to opposite conductors of the cable: phase and neutral or phase and screen. In a car, this is ground and signal wire;
5. The screen should remain displaying infinity; if there is any value instead, it means there is a short circuit somewhere. Changing values ​​indicate interference in the network.

In addition to ordinary wires, there are high-voltage wires that can withstand high current and voltage loads. These include spark plug wires in cars. The current that is required when starting the engine flows through them; this current reaches 80-150 amperes. Knowing how to test high-voltage wires with a multimeter is required when diagnosing car electronics. The ringing of these wires occurs according to the specified scheme, with the difference that it is necessary to set a larger resistance measurement limit. Typically this limit should be set at 20 kilo-ohms.

In trucks, as well as in networks located in places subject to constant mechanical stress, conductors with a screen - armor or armored wires - are placed. The only special feature of the armored wire is the screen, made of durable metal. You can check the integrity and insulation of the armored wire in the same way as a regular one, you only need to have access to its ends and the screen outlet.

Method for checking the condition of electrical wiring

The check is carried out in several cases - after the initial electrical installation, after purchasing the premises, in case of malfunctions. There are several ways to check the electrical wiring in an apartment. Each one helps in certain cases.

Insulation fault check

The insulating layer - its quality and condition - has an impact on the operation of the electrical system. Problems may occur during manufacturing, transportation, or operation. The main ways to check electrical insulation in an apartment:

• periodic, independently or with the help of professional electricians;
• automatic, through special devices throughout the entire technical cycle.

In the first case, a multimeter is used. It is mandatory to assess the external condition of all accessible cables. Insulation is checked through measurement and testing. In stranded wires, the absence of short circuits between them is checked by connecting them alternately.

Checking the integrity of a single piece of wire

Broken wire is one of the most common wiring problems. There can be a lot of reasons; the testing methods depend on which cable needs to be examined:

1. Cutting (the wire lies on the table) - touch both ends with probes (parameters for “Ohm” or “Ω”, value 1000 Ohm). If there is a malfunction, the device will show EL or a very large number.
2. Hidden wiring - the wires are de-energized, separated from the devices, and the ends are connected with a separate wire to create a whole circuit for testing. Next, each is examined with a multimeter.

When working with a cable (even without power), do not touch it with your hands or other parts of the body. Devices and probes are protected by special plastic attachments by which they should be held.

Determining the presence of a short circuit

Knowing how to use a multimeter and how to check the electrical wiring in an apartment, you can find the location of the short circuit. Sometimes devices turn off for no obvious reason. It is necessary to determine the presence or absence of contact.

A short circuit is a connection between the neutral and phase wires without appropriate resistance. Thus, it is enough to check only these two cables. In addition to de-energizing, switches are removed, lamps and appliances are turned off. Check in a junction box or a non-working outlet.

How to check a generator diode bridge with a multimeter

The diode bridge in the generator is a kind of rectifier, with the help of which the alternating current generated by the generator is converted into direct current. It includes 6 semiconductor diodes, 3 of them with a positive value, and 3 with a negative value. Each of these groups passes current only in one, strictly defined direction.

Alternating current is used when it needs to be transmitted over long distances. Electrical appliances installed in the car require constant current, including charging the battery. Since the generator is capable of producing only alternating current, a diode bridge is needed to convert it to direct current.

The design includes two metal plates that conduct electric current. Diodes are installed on their plane in order of priority. The alternating voltage produced by the generator changes the direction in which the electrons move. In order to obtain a constant voltage, it is necessary to redirect their movement in the so-called wrong direction; as a result of further operation of the phases, a constant current will be created. In this circuit, the battery serves as a kind of capacitor that successfully dampens voltage fluctuations. If necessary, you should check the generator using a multimeter.

Quite often the diode bridge fails. A similar situation occurs when the polarity of the battery is not observed, or the electrical circuit in the generator itself is short-circuited. Any malfunction of the diode bridge negatively affects the entire on-board network. If one of the diodes breaks or the diode is broken, then dips appear in the stable pulsating voltage at the generator output, since the faulty diode stops supplying voltage to the on-board network.

The battery takes on some compensation for dips using its own resources, but the overall network voltage is still reduced. In addition to affecting stability, dips lead to electromagnetic interference, which negatively affects sound-reproducing equipment. If there are a large number of such violations, a mandatory check of the diode bridge will most likely be required. For this purpose, you will have to check the generator for functionality with a multimeter, having first removed it from the engine. The diode bridge is disconnected and called by the tester.

It is advisable to use the instruction manual during disassembly as this operation may vary from machine to machine. On some models, the bridge is secured with bolts, while on others it is simply soldered. Marks are applied to the diode bridge and generator to avoid confusion during subsequent assembly.

• The multimeter must be switched to resistance measurement mode and the sound indication must be set.
• Next, the probes of the measuring device are connected to each terminal of the diode. The negative terminal - “minus” is connected to the central steel or aluminum plate, and the positive terminal is connected to a metal core made in the form of a tinned bare wire, the diameter of which must be at least 1 mm.
• To check each diode, you must first touch the core or central plate with one probe, and the opposite terminal of the diode with the other probe. After this, the probes must be swapped.
• If the diode is working properly, the multimeter will produce sound signals only when the probes are in a certain position. If the tester beeps with all connection options, this indicates that the diode is broken. If there are no sound signals at all, then the diode is broken. The instrument should emit audible signals when only one side of the bridge is being inspected.

There is another method for checking the generator with a multimeter. In this case, resistance is used - the main physical quantity. To carry out measurements in this way, the switch must be set to 1 kOhm. Touches with probes are carried out as in the previous version. When checking one direction, the device should produce a result of 500-800 Ohms, and when checking the other, infinity. In this case, all bridge diodes are in working condition.

Algorithm of actions

Let's consider the situation. There is a computer in the room. It is connected via a patch cord to the router, which, in turn, is connected via an Internet cable to the provider’s equipment to access the global network. At one point, the network checker on the computer shows that the connection is unavailable or not connected.

Troubleshooting

A superficial check can be done using the command to ping all hosts on the home network and several remote Internet servers. For these purposes, open a command prompt as an administrator. Next, enter the commands, focusing on the algorithm of actions:

1. Testing the operation of the network card of the computer itself is done by exchanging test packets with itself. If there are no losses, then everything is in order. The ping 127.1.1.0 command.

Fault Analysis

We will start from the losses received when sending packets

It is important to understand that the ping command is a protocol of the fourth level according to the nesting of the OSI model, that is, software, network and hardware errors are excluded, but data levels 5-7 according to the OSI model are not checked

How to check an Internet cable or local cable and understand that there is a break? Eliminate other options related to a faulty network card or router. If there were packet losses when scanning the computer itself:

1. Restart your network connection.
2. Disconnect from all network add-ons (VPN, proxy).
3. Do a Network Reset.

Checking twisted pair breakage and insulation integrity

The following video describes 5 ways to test twisted pair cables:

If all indications are that there is a problem with the cable, it must be identified and corrected. If a short cable is faulty, you can simply replace it. For wires several tens of meters long, you can use special devices to help identify the problem.

Tester

MicroScanner2 is a professional solution for identifying the location of cable faults. By connecting one connector to the port, graphical information about the length of the patch cord to the fault location will be displayed on the tester screen.

Multimeter

In resistance mode, you need to ring the orange and green twisted pair to check the integrity of the cable:

1. Remove the second connector from the PC's network card or other network equipment.
2. Remove the connector from the end to be measured and expose the wires.
3. Apply the tester probes first to the orange and white-orange conductor of the twisted pair. Normal resistance is 1-2 ohms.
4. Next, apply to green and white-green. The resistance should also be 1-2 ohms. The polarity is not important.
5. Then attach the multimeter probes to the orange and green conductors. The multimeter should read more than 100 ohms. Multimeters usually indicate infinity.

How to measure the voltage in an outlet

One of the most common tasks is measuring the voltage in an outlet or in apartment wiring. This is very easy to do with a multimeter. As we already wrote above, alternating current flows in sockets, so to measure it you need to set the switch on the multimeter to the ACV zone.

We know that the voltage should be approximately 220 volts, so if you have a multimeter like the example in the photo above, set the switch to a mark higher than the expected value, in this case 750 in the ACV range.

Having set up the device, it’s time to put your probe fingers into the socket. It makes no difference which wire is inserted into which hole in the socket. In general, there is nothing to be afraid of here, the main thing is to hold on to the insulated part of the probes and not touch their metal part (although this is quite difficult to do even with a strong desire), and also not to allow them to touch each other while they are inserted into the socket, otherwise you can cause a short circuit .

If you did everything correctly, the screen of your multimeter will show the current voltage in the outlet and your indoor wiring.

In our case, this is 235.8 volts - within normal limits. You will never see exactly 220V on the screen, so an error of +-20 is normal.