How to find the phase with a multimeter: detailed instructions with step-by-step photographs for beginners with an explanation of typical mistakes of novice electricians. How to find the phase and zero with an indicator screwdriver: safe ways How to determine the phase and zero of an indicator

Generators that produce electricity at power plants have three windings, one of the ends of which is connected together, and this common wire is called Zero. The remaining three free ends of the windings are called phases.

Colors and designation of wires

In order to find the phase, neutral and ground wires of the electrical wiring without devices, they, in accordance with the rules of the PUE, are covered with insulation of different colors.

The photo shows the color coding of the electric cable for single-phase electrical wiring with a voltage of alternating current 220 V.

This photo shows the color coding of an electrical cable for 3-phase AC 380V wiring.

According to the presented schemes, wires have been marked in Russia since 2011. In the USSR, the color marking was different, which must be taken into account when searching for phase and zero when connecting installation electrical products to old electrical wiring.

Wire color chart before and after 2011

The table shows the color marking of electrical wiring wires adopted in the USSR and Russia.
In some other countries, the color coding is different, except yellow - green wires. There is no international standard yet.

The designation L1, L2 and L3 do not represent the same phase conductor. The voltage between these wires is 380 V. Between any of the phase and neutral wires, the voltage is 220 V, and it is supplied to the electrical wiring of a house or apartment.

What is the difference between N and PE wires in electrical wiring

According to the modern requirements of the PUE, in addition to the phase and neutral wires, a ground wire must also be supplied to the apartment yellow - green.

Zero N and ground wires PE are connected to one grounded shield bus in the entrance of the house. But they perform a different function. The neutral wire is designed for electrical wiring, and the ground wire is designed to protect a person from electric shock and is connected to the housings of electrical appliances through the third contact of the electrical plug. If an insulation breakdown occurs and the phase enters the body of the electrical appliance, then all the current will flow through the ground wire, the fuses will blow out or the circuit breaker will trip, and the person will not be harmed.

If the wiring is laid indoors with a cable without color marking, then it is impossible to determine where the zero conductor is and where the ground conductor is with devices, since the resistance between the wires is hundredths of an ohm. The only clue may be the fact that the neutral wire is wound into an electric meter, and the ground wire passes by the meter.

Attention! Touching exposed parts of a circuit connected to an electrical outlet may result in electric shock.

Probe indicators for searching for phase and zero

A device designed to search for zero and phase is called an indicator. Light indicators for determining the phase on neon bulbs have been widely used. Low price, high reliability, long service life. Recently, indicators have also appeared on LEDs. They are more expensive and additionally require batteries.

On a neon light

It is a dielectric case, inside of which there is a resistor and a neon light bulb. Touching in turn to the wires of the electrical wiring with the screwdriver end of the indicator, you find the phase by the glow of the neon bulb. If the light bulb lit up from touch, then this is a phase wire. If it does not glow, then this is a neutral wire.

Cases of indicators come in different shapes, colors, but the filling is the same for all. To prevent accidental shorting, I advise you to put a tube of insulating material on the screwdriver shaft. Do not use the indicator to unscrew or tighten the screws with great force. The indicator body is made of soft plastic, the screwdriver shaft is pressed in shallowly and the body breaks under heavy load.

Probe LED indicator

A probe indicator for determining the phase on LEDs appeared relatively recently and are gaining more and more popularity, as they allow not only to find the phase, but also to ring the circuits, check the health of incandescent bulbs, heating elements of household appliances, switches, network wires and much more. There are models with which you can locate the electrical wire in the walls (so as not to damage when drilling) and find, if necessary, the place of their damage.

The design of the LED indicator-probe is the same as on the neon light bulb. Only instead of it, active elements are used (a field-effect transistor or a microcircuit), an LED and several small-sized DC batteries. Batteries last for several years.

To find the phase with the LED indicator-probe, its screwdriver end is touched sequentially to the conductors, while you can’t touch the metal platform at the end with your hand. This site is used only when checking the integrity of electrical circuits. If, when searching for a phase, you touch this site, the LED will also shine when the indicator touches the neutral wire!

A brightly lit LED will indicate the presence of a phase. According to the rules, the phase wire should be on the right side of the outlet. How to check contacts and circuits with such a probe indicator is described in detail in the instructions attached to it.

How to make a test indicator yourself
to search for phase and zero on a neon light bulb

If necessary, you can make a probe indicator with your own hands to search and determine the phase.

To do this, you need to one of the conclusions of any neon light bulb, even a starter from a fluorescent lamp, solder a resistor with a nominal value of 1.5-2 MΩ and put an insulating tube on it.

A light bulb with a resistor can be placed in a screwdriver handle or a ballpoint pen case. Then the appearance of a home-made indicator-probe will differ little from the industrial design.

The search or phase determination is performed in the same way as with an industrial probe indicator. Holding the light bulb by the base, touch the conductor with the end of the resistor.

When choosing a resistor, sometimes it is difficult to determine its value if colored rings are applied to the resistor body instead of a number. An online calculator will help you with this task.

Why is the indicator glowing
when touching the neutral wire

I have been asked this question many times. One of the reasons is the incorrect use of the LED indicator. How to properly hold the LED indicator-probe when searching for a phase is written in the article above.

The second possible reason for this behavior of the indicator is a break in the neutral wire. For example, the circuit breaker, installed after the meter on the neutral wire, worked. In old apartments, this is not uncommon and is a gross violation of the arrangement of electrical wiring. It is mandatory to remove the machine from the neutral wire or short-circuit its outputs with a jumper.

When the neutral wire breaks, a phase enters it through the devices connected to the mains, for example, through the switch backlight indicator, TV in standby mode, any charger that is turned off only by the start button, the computer and other electrical appliances, the phase arrives. The indicator shows this. In this case, the neutral wire can be dangerous and touching it is unacceptable. It is necessary to find and eliminate a break in the neutral wire, which can also be located in junction boxes.

How to find phase and zero using an electrician's control

To check the presence of supply voltage in the electrical network, earlier electricians used a home-made control, which is a low-power incandescent bulb screwed into an electric cartridge. Two conductors of stranded wire about 50 cm long are connected to the cartridge.

In order to check the presence of voltage, you need to touch the conductors of the control to the wires of the electrical wiring. If the light is on, there is voltage.

Checking an electrician on a light bulb requires careful handling and takes up a lot of space. It is much more convenient to make an electrician's control on the LED according to the diagram below.

The circuit is simple, in series with any LED, a current-limiting resistance is switched on. LED of any type and color of glow. Use it in the same way as an electrician's control on a light bulb.

The LED and resistor can be housed in a suitably sized ballpoint pen case. In the photo is a control for a motorist. The scheme of such control is the same. Only depending on the type of LED used, the resistor R1 is set to a value of about 1 kOhm.

It is easy to check the presence of voltage on the wires in the vehicle's on-board network with such a control, the right end is connected to ground according to the diagram, and the left end touches any contact. If there is voltage on the contact, the LED will light up. If you touch the positive terminal of the battery with one end of the fuse, and touch the other with the control, then if the LED does not light, then the fuse is open. So you can check both incandescent bulbs and the presence of contact in the switches.

Phase search in the presence of neutral and ground conductors

If you want to find a phase in the wiring, which has phase, neutral and ground wires, then using the control it is easy to do. It is enough to perform three touches with the control wires. It is necessary to assign a conditional number to each wire, for example 1, 2 and 3, and in turn touch the pairs of wires 1 - 2, 2 - 3, 3 - 1.

The following behavior of the light bulb is possible. If, when you touch 1 - 2, the light does not light up, then the wire is 3-phase. If it shines when you touch 2 - 3 and 3 - 1, then it is 3-phase. The meaning is simple, when you touch the neutral and ground conductors, the light bulb will not shine, since in practice these are conductors connected together on the shield.

Instead of control, you can turn on any AC voltmeter, designed to measure voltages of at least 300 V. If you touch the phase wire with one voltmeter probe and the zero or ground wire with the other, the voltmeter will show the mains voltage.

Search for phase and zero by control

Attention, touching any bare conductors while searching for a phase with a control can result in electric shock.

Everything is done very simply, one end of the control wire is connected to a central heating or plumbing pipe stripped to metal, and the other in turn touches the wires or electrical wiring contacts. When you touch the phase wire, the bulb will light up.

If the metal of the pipe cannot be reached, then you can use the water flowing from the mixer. To do this, turn on the water and place one control wire under the stream of water as close as possible to the mixer. The second end of the wire touches the wires of the electrical wiring. The weak light of the bulb will tell you where the phase is.

It is best to screw the smallest light bulb into the control box, I used a 7.5 W refrigerator light bulb. In order to reach the water, you can use a piece of any wire or a standard extension cord.

Search for phase and zero with a voltmeter or multimeter

Finding the phase with a voltmeter or multimeter is carried out in the same way as with an electrician's control, only the probes of the device are connected instead of the ends of the control.

To determine zero in a three-phase network using a tester or multimeter, it is enough to measure the voltage between the wires, which will be 380 V between the phases, and 220 V between zero and any of the phases. That is, the wire relative to which the voltmeter will show 220 V on the other three and there is zero.

Finding phase and zero with potatoes

If you don’t have the technical means to find the phase at hand, then you can successfully use an exotic or folk, you can’t call it otherwise, method for determining the phase, using potatoes. Don't think this is a joke. For some, this may be the only available method that can be successfully applied in practice.

The end of one conductor must be connected to a water pipe (if it is not plastic) or a radiator. If the pipe is painted, then the connection point must be cleaned to metal in order to ensure electrical contact. Insert the opposite end into the potato slice. The other conductor is also stuck with one end at the maximum distance from the previous one into the potato, with the second end through a resistor with a nominal value of at least 1 MΩ, they touch the electrical wires in turn. Some time to wait. If there is no reaction on the cut of the potato, this is zero, if there is, it is a phase. I do not recommend using this method if you do not know the safety rules for working with electrical installations.

As you can see, in the photo around the wires, when the electrical wiring was connected to the phase wire, changes occurred on the cut surface of the potato. When you touch the neutral wire, there will be no reaction.

In every house there are electrical appliances and electrical wiring, in the operation of which there are some difficulties. Calling a professional electrician for every little reason will cost a pretty penny, it's much easier to solve the problem yourself. For these purposes, you may need a multimeter that measures network parameters. However, the tool is expensive, and it is not always advisable to purchase it for use at home. Its functions can be replaced by an indicator screwdriver. What is it and how to use it? How to determine where the phase is, and where is zero?

Principle of operation

How does an indicator screwdriver work? The appearance of the device is similar to an ordinary screwdriver, but it has an indicator built into the cavity of the handle. The metal part of the screwdriver acts as a probe, while it is able to reduce the strength of the supplied electricity so that the use of the device is as safe as possible. Also, the device has an LED, which is located at the top of the handle. In addition, the screwdriver has a metal plate of the contact type.

The principle of operation is quite simple - the probe of the screwdriver touches the conductor of electricity, then, passing through it, the current strength decreases significantly, after which the person touches the contact plate with his finger. The circuit is closed, causing the light to turn on. A screwdriver is needed in order to show the presence of direct or alternating current in the network.

Varieties of screwdrivers

To date, the assortment of any hardware store includes the following types of indicator screwdrivers:

1. Safeline multifunctional screwdriver.
2. MS 18.
3. Lek OP 1.
4. Lek OP 2E.
5. VM 1141 220 250V.
6. Indicator screwdriver with battery.

The presented modifications of the device have some difference in functionality.

Screwdriver options

The standard device is designed for the following purposes:

1. The indicator screwdriver shows phase or zero.
2. Determination of hidden wiring in a non-contact way.
3. Determining the location of the cable break.
4. Determining the polarity of the batteries.
5. Checking the integrity of the electrical circuit.

Depending on the modification of the screwdriver, it may have other additional functions.

Definition of zero and phase

Many novice electricians and people who decide to repair electrical appliances on their own are interested in how to find the phase and zero with an indicator screwdriver. To do this, follow the following algorithm of work:

• first, the wiring is de-energized;
• the wires to be tested must be stripped from the insulating winding;
• after which it is necessary to turn on the electricity;
• the probe must alternately touch the wires, while remembering that the circuit must be closed with a finger on the contact plate;
• the wire, when touched, to which the light bulb lights up, is the phase of the electrical circuit.

How to find phase and zero with an indicator screwdriver in a socket? To do this, you need to alternately place the probe into the holes of the outlet. When a phase is detected, the light will turn on. There will be no glow if the screwdriver shows zero. If, when touching both holes of the socket, the light does not light up, this indicates a break in the zero.

In addition to using an indicator screwdriver, you can determine the phase by the color of the wire:

• yellow-green wire is ground;
• phase wire color - black;
• zero has a blue wire color.

If the color distribution is not respected, you will need an indicator screwdriver to determine.

Checking the health of incandescent lamps

When buying another incandescent light bulb, it is important to check its performance right in the store. If there is no corresponding stand, this can be done using an ordinary indicator screwdriver. To do this, you need to take the lamp with one hand by the metal base, and with the probe of the indicator screwdriver in the other hand, touch the central contact on the bulb. If it is correct, the LED on the device will light up.

Although the method is effective, the result may be a failure if the light bulb is depressurized. In this case, the electrical circuit is maintained, but the lamp still does not light up. However, this happens quite rarely.

Checking the heating element

You can check the performance of the heating element of the washing machine without even removing it. It is enough to provide access to the contacts, while the remaining wires must be disconnected. To check, you need to touch one of the contacts of the heating element with your hand, with a screwdriver probe - to the other. In this case, the circuit is closed by touching the metal plate on the device. If the lamp lights up, the heating element is OK.

Checking the voltage in an insulated wire

How does an indicator screwdriver work? Its functionality allows not only to determine the phase and zero, but also to check the voltage in wires with insulation. It is not recommended to bite an unknown wire, as it is often not clear whether it is energized or not. In this case, the following manipulations are carried out:

• take the indicator screwdriver directly by the probe;
• a metal plate must be attached to the wire;
• if the cable is live, then the indicator on the screwdriver will show this.

This method of determination is suitable even for wires that are under plaster, however, the glow may be less bright.

Finding a broken wire

The instruction for the indicator screwdriver notes the versatility of the device. It is very important and convenient for home use. Having figured out how to find the phase and zero with an indicator screwdriver, you can also find a wire break with it. If the carrier suddenly stops working, then the first step is to check the integrity of the electrical circuit:

Similarly, a wire break is searched for in the wiring of the house.

Electronic indicator screwdriver

You can find the phase and zero with both an indicator screwdriver with an LED and an electronic one. The only difference is in their design. An electronic indicator screwdriver can be either with or without a liquid crystal screen.

Instead of a light signal, such a device notifies you of the presence of voltage with an audible signal. In addition, a great advantage of such a device is the output of information about the voltage on the liquid crystal screen, if any. The principle of operation of the electronic device is the same as that of a conventional indicator screwdriver.

Health check

Before you determine where the phase is and where is zero, you need to check the performance of the screwdriver itself, since it, like any other device, may be faulty. To do this, you should pay attention to such nuances:

1. The body of the device must maintain its integrity. Working with electricity requires good insulation without damage.
2. For accurate readings, check the screwdriver. To do this, touch the probe with the probe to the conductor, which is 100% energized.
3. If you use a battery-powered product, you need to replace them in time.

Safety when using a screwdriver is extremely important, so if a problem is found, it is recommended to purchase a new device. The cost varies from 50 to 1000 rubles. depending on modification.

Security measures

When working with the device, the following safety precautions must be observed:

1. Do not disassemble the screwdriver, replace only the batteries, if any.
2. The use of a damaged screwdriver is strictly prohibited.
3. Do not use the device without a screw.
4. When the probe comes into contact with electricity, do not touch the bare part of the device with your hands.
5. Do not use the device at voltages higher than indicated in the technical specifications.

In order to find out whether the phase or zero on the indicator screwdriver is lit, you need to follow all the recommendations outlined above. At the same time, it is important to monitor the health of the device and not neglect the rules for the safe use of an indicator screwdriver.

When connecting various electrical devices (socket or switch), it is not necessary to take into account the polarity of the conductors. But what if the wiring used in the house is three-core and does not have a color marking, and the devices must be connected with a grounding conductor. To do this, there are several ways to check which of the wires is phase, zero or ground.

Determination of phase and zero without instruments

There are situations when, for the correct connection, it is necessary to find out which wire is the phase and which is zero. For example, to ensure the normal operation of the lighting device, a phase wire is cut into the gap (through the switch), and the zero wire is laid directly to the lighting device. Currently, wiring in houses and apartments is laid with three-core wires, which are divided into three types.

Types of conductors:

• Phase;
• Zero;
• Grounding.

It is possible to distinguish the phase from zero in the wiring visually. But for this, one important condition must be met. Wiring in a house or apartment should be made using multi-colored conductors.

The phase conductor according to the GOST rules must be marked with the following colors: black, white, brown, purple, turquoise, red, gray, pink and orange.

Note! The most common colors found for marking phase wires are white, brown and pink.

The neutral conductor is easy to find, as it is always marked in blue. The ground wire is yellow-green.

It is worth noting that the electric current that is supplied to the residential sectors is variable, so the polarity of connecting electrical appliances does not matter. Proper connection is only important for DC equipment.

Phase and zero in the socket: how to determine with an indicator screwdriver

The easiest way to determine the phase conductor is to use a conventional indicator screwdriver. Currently, there are a huge number of these devices on the market.

Indicator types:

• With neon indicator;
• With the use of LEDs.

An indicator using a neon bulb is made in the form of a dielectric case, inside of which there is a neon lamp with a resistor connected to it.

The design of LED indicators is presented in the form of a conventional screwdriver, inside which there is an LED, a microcircuit and several small batteries. These devices, having different characteristics, are similar in principle of operation.

It is important to know! It is possible to determine the phase conductor only if there is voltage in the electrical network.

In order to find the phase in the wiring, you must do the following. The voltage is removed from the conductor. This is done by turning off the circuit breaker in the electrical panel.

After that, the wires are stripped of insulation to a length of about 1 - 2 cm. The ends of the wire are pulled apart, this will help to avoid a short circuit between these conductors.

Voltage is applied to the wire by turning on the circuit breaker. Then, the metal part of the indicator is applied in turn to each and wires. The illuminated indicator will indicate the working phase in the wiring.

It is worth noting that some devices, due to their design features, can be equipped with a metal plate in the upper part. To correctly determine the phase conductor, it is not necessary to touch it.

How to find the phase, zero and ground with a multimeter

If the phase conductor is easy to detect using an indicator screwdriver, then it is not possible to determine zero and ground with its help. Since these conductors do not affect the operation of the indicator in any way. In this case, it makes sense to use a multimeter.

To determine you need:

• Multimeter (tester);
• The presence of voltage 220 V.

The definition of each of the conductors should begin with the preparation of the device. Probes are connected to the plugs under the name COM and V.

If you need to find a phase wire, then for this, by turning the switch, on the multimeter, you must select the value of the measurement of alternating current in the range of more than 220 volts. After that, the probe that is connected to the socket with the name V, we touch all the conductors in turn. When touching the phase conductor, the display of the device will show values ​​​​from 8 to 15 Volts. The neutral and ground conductor will not change these readings.

Note! When working on energized wiring, be sure to follow the safety rules.

After the phase conductor is found, you can start searching for the zero one. To do this, with any probe of the multimeter we touch the phase conductor, with the other we close the contact with any of the other conductors. The neutral conductor will be indicated by the value of 220 Volts that appears on the display of the device.

The third conductor will be the ground conductor. The readings on the display when touching the phase and ground wires are always lower than 220V.

Non-standard ways: how to determine the phase in the wiring

It should be borne in mind that these methods are unsafe. It is recommended to use them only if all necessary safety measures are observed.

Definition methods:

• Homemade control light;
• Potato.

To make a control light, you will need an ordinary cartridge, an incandescent lamp of any fashion and a meter wire. First of all, we clean the wire from insulation by about 1 cm. Next, we disassemble the cartridge and connect the ends of the wire to its terminals.

Then, in order not to damage the light bulb, it is necessary to strip the remaining ends of the wire to a length of 3 cm. We screw the light bulb into the prepared device. After that, turning off the voltage, we clean the ends of the conductor on which it is necessary to find the phase wire.

It is not necessary to twist the contacts of the control bulb with the wire, since free access to the conductor contacts is required.

Next, using any metal object, we clean a small area on the metal surface of the water pipe. We apply voltage to the conductor and with one contact of the control we touch the stripped area on the pipe, and with the second one of the contacts of the wire. When touching the phase conductor, the lamp will light up.

Using a potato, check which of the phase wires is presented as follows. The device will require two meter-long wires and a 1 mΩ resistor. One of the wires must be mounted in a potato and attached to the pipe. The other wire is mounted in a potato with one of the ends, and the phase wire is searched for with the other. The appearance of browning on the potato will indicate the phase wire.

Understanding how to determine the phase and zero (video)

As practice shows, in most cases, the search for phase and neutral conductors in the AC electrical network is not necessary, since the polarity does not matter when connecting various household devices.

How to determine the phase? Most often, this question is asked when it is necessary to determine the phase in a home outlet or in wiring. The mains voltage that enters your house comes through two wires, one of which is phase and the other is zero. In this article, you will find two ways to determine the phase in your home wiring or outlet.

Using an indicator screwdriver

On the market or in a radio store you can often see phase-indicating screwdrivers. Most often they are called probes. In appearance, the probe is a flat screwdriver, which consists of an iron probe, high-resistance a and a neon light bulb. They are all connected in series.

Let's try to determine the phase in practice using our phase-indicating screwdriver. In order to do this, we need to touch the tip of the screwdriver with our finger, thereby closing the phase-probe-we-ground circuit if we poke on the phase. A current will flow through, but it will be so weak that you won't even feel anything. Meanwhile, the neon light on the screwdriver will light up. So we are in a phase.

We stick a probe and get to "zero". The neon light is off. This means that the other contact of the socket is definitely a phase.

We check and make sure. The neon light is on, so this is our phase.

Using a multimeter

What if we don't have an indicator screwdriver? How to be in this case? For these purposes, you can use an ordinary. We put the twist on the measurement of alternating voltage and take any multimeter in our hands.

We plug the second probe into the socket and see what our multimeter will show on the display. If we touch zero, then zeros or a few volts will appear on the multimeter display. If we touch the phase, then a decent voltage will appear on the display of the multimeter - this is the phase. Below in the photo we have determined the phase.

If it also shows zeros, then grasp the battery with one hand and the multimeter probe with the other. It is possible that your floor is very well insulated from the ground. When you measure in this way, the main thing is not to confuse the mode of measuring voltage and current. If you accidentally put the multimeter's knob into current measurement mode and touch the battery, it can even be fatal! Be very careful if you use this method.

All the same operations apply to a three-phase network, where we have three phase wires and one zero.

Modern indicator screwdrivers will relieve the headache of a person trying to figure out how to determine the phase, zero, ground. Difficulties noted below. For testing, a signal generated by a screwdriver is used. Of course, there are batteries inside. The old Soviet indicator screwdriver based on a single gas-discharge light bulb is unusable. Allows you to accurately determine the phase. Therefore, the other circuit is zero or ground.

Correctly determine the phase

Three-core wires

Let's start with terms. The Russian language is deprived of the word zero. But it was used in everyday life due to easy pronunciation. Zero is a distorted zero, originating from the Latin language. The programmer knows: the term NULL is used to mean empty, undefined variables (devoid of a type). Sometimes the type of data is convenient for compiling algorithms (when passing function values).

Now let's try to find the phase. A typical indicator screwdriver is formed by a steel probe, followed by a high-resistance resistance (for example, carbon), which limits the current, a small gas discharge lamp acts as a light source. Little things, but those who do not know the term contact button, are powerless to define zero. At the end of the indicator screwdriver handle there is a metal platform. This is a contact button that you bother to touch with your finger. Otherwise, the light bulb will refuse to glow when touching the phase.

Let's explain what's going on. The human body is endowed with capacity. Not so great, enough to pass a meager current. The phase begins to oscillate, the electrons go to the network and back. A small current is generated. The size is highly limited by the resistor; It is impossible to detect the ground directly with the instrument.

Phase detection is fundamental, no voltage should be applied to the chandelier socket when the switch is off. Otherwise, the usual process of changing a light bulb can become dangerous, the last. According to the regulations, the socket phase is on the left. If the switches are set as usual (turned on by pressing up), the methods for determining the phase degenerate by the ability to find the left hand, to understand where the bottom is:

Determining the position of the phase by the color of the insulation of the wire cores

The zero working wire is provided with blue insulation, the earth is yellow-green. Accordingly, the red (brown) color falls on the phase. The rule can be grossly violated. Houses of old buildings were often equipped with wires of two cores. The color of the insulation is in each case white. Individual devices, such as light or motion sensors, have a different layout. For example, the neutral wire is black. Here, get ready to look at the instruction manual, there are countless layout options.

Find a neutral wire in the apartment

According to the rules, the body of the access shield is grounded. It is carried out using a solid-sized terminal, tightened with a powerful bolt in old-built houses, it is easier for residents of modern buildings to navigate the number of cores. The zero bus has the largest number of connections, the phases are divided into apartments (good electricians hang stickers A, B, C; evil ones do not hang them). We can easily trace the layout of circuit breakers, counters.

230 volt UK plug

In each case, the common wire will be zero. Color does not play a decisive role. Although according to the norms, modern cables are equipped with painted insulation. Please note - if the house is equipped with grounding, lived at the entrance at least 5. The body of the shield is planted on yellow-green. The neutral wire will serve to drain the operating current from the devices (closes the circuit). Merging branches on the consumer side is not allowed. Here are three rules that help you figure out the access shield (note, according to the rules, the tenant should not show his nose there at all - they warned):

• The circuit breaker breaks the phase. There are two-pole models, they are used relatively rarely for rooms with special danger (bathroom). Therefore, by the position of the wire, it will be possible to say: this is a phase. Then it’s worth turning off the machine, ringing the vein on the side of the apartment. Definitely gives the position of the phase.
• The voltage between the neutral wire, any phase is 230 volts. Based on the key feature, we select a vein that gives the indicated difference to another. The spread between the phases is 400 volts. Percentage values ​​are 10 higher, Russian chains are trying to meet European standards.
• With current clamps, we measure the values ​​​​on the conductors. For each phase, a value will appear, the sum of which (by three) must flow back into the network along the zero (or suitable phase) one. Grounding is rarely used, the current here is close to zero with a uniform loading of the branches. The place where the value is the most is traditionally the null conductor.
• The ground terminal of the switchboard is visible. The sign will help to find the neutral wire in houses with NT-C-S. In other cases, grounding is supplied here.

Additional information about finding the ground, phase, neutral wire

We remind you that cases were considered when there is no indicator screwdriver at hand, but there are current clamps, a multimeter. Then, before entering the apartment, they find the ground, phase, neutral wire, the home network is called. There are three cores, the technique lies on the surface: between the phase and the other wire, the potential difference will be 230 volts. Please note that the technique is not suitable in other cases. For example, the voltage difference between two identical phase cores is round zero. It is difficult to measure and determine with a tester.

Let's add another way - the industry is prohibited. Bulb in a socket with two bare wires. Using a tool, they find a phase, it is possible to close the core to ground. Do not use water, gas, sewer pipes, other engineering structures. According to the rules, the braid of the cable antenna is equipped with grounding (grounding). Relative to it, it is permissible for a tester (a light bulb in a cartridge prohibited by standards) to find a phase.

For determined people, we recommend fire escapes, steel tires for lightning rods. It is necessary to clean the metal to a shine, call the phase site. Please note that not all fire escapes are grounded (although they must be), lightning rod tires are 100%. If you find such a flagrant arbitrariness, contact the governing organizations, if there is no reaction, inform the state authorities. Indicate violation of the rules of protective zeroing of buildings.

Modern screwdriver-indicators for determining the phase, neutral wire, earth

When it is impossible to understand what color the wires are, it is useful to use an indicator screwdriver. The instruction of the curiosity on batteries says: it will be possible to find the ground with the help of a probe. We hasten to disappoint readers - any long conductor is defined falsely. A phase broken in the area of ​​traffic jams, a neutral wire, a real earth - there is only one answer. Not every indicator screwdriver is able to perform the functions equally effectively. The meaning of the operation is as follows:

Screwdriver indicator

• An active indicator screwdriver is able to detect a long conductor by emitting a signal there, catching a response.
• In practice, if the quality of the contacts is poor, the wave quickly decays. An indicator screwdriver shows the presence of earth on an open phase plug.
• To determine the ground, there is a condition - you need to touch the contact pad with your finger. This is the difference between active and passive indicator screwdrivers. In the first one, it is possible to find the phase according to this principle, in the second, the correct determination occurs if there is no contact with this area.

A modern screwdriver-indicator at a distance will allow you to judge whether current flows through the wire. There is a special remote mode. Usually even two: increased and decreased sensitivity. Allows you to weed out the unused part of the wiring. Suppose there are known cases: builders brought two phases into the house instead of one, they confused them in places. Wiring must be used with great care.

I would like to note that in practice it is not easy to measure the resistance of the wiring. It is much more convenient to determine the presence of a phase. There is no danger of burning the Chinese tester (it happens at times when trying to measure the resistance of a live conductor). You should also be aware that low-resistance circuits are determined with an error. For example, most testers with a direct circuit of the probes do not give a zero scale. But if you can’t determine the ground using an active indicator screwdriver, bad contacts are easy. If, when the plugs are turned off, the light burns with a finger pressed to the contact pad, it's time to think about buying a new junction box machine, replace the twists with modern caps.

1. Red - phase.
2. Blue - neutral wire.
3. Yellow is earth.

Usually water-soluble paint is washed off with difficulty. The colors of the electrical wires can be put down with the colors of the printers. The above system is not alone, often occurs. On sale we will find black color. You can use it however you like. Wire marking is done once and for all. It is easier to wash off the marking with concentrated acetic acid, the substance will be needed by those who intend to clean their hands (it is not always easy in practice). Finally, try not to stain your clothes.