What color wire goes to the phase. Marking electrical wires by color: expert advice

The color marking of wires is far from being an advertising "chip" of manufacturers, as some novice electricians believe. This is a special designation that allows the electrician to determine zero, ground and phase without the use of additional measuring instruments.

If the contacts are connected incorrectly, unpleasant consequences can occur in the form of a short circuit and electric shock to a person.

The main purpose of applying color coding is a reduction in the timing of connecting contacts and creating safe conditions during the electrical work. At the moment, in accordance with the PUE and European standards, each core has its own clearly defined color.

We will talk about the color of the neutral wire, grounding and phase.

Ground wire

By standards, the insulation of the "earth" is painted in a yellow-green hue. Some manufacturers apply yellow-green stripes to the ground conductor in the longitudinal and transverse directions. Rarely, but still found, shells are pure green or pure yellow.

On the electrical diagrams"earth" is denoted by two Latin letters "PE". Grounding is often called zero protection, but this is not a working zero, not to be confused.

Neutral wire

As in single phase electrical network, and three-phase, the neutral is painted in blue or blue. On the wiring diagram, zero is indicated Latin letter"N". Neutral is also called zero or neutral working contact.

phase wire

This wire, depending on the manufacturer, is marked with the following colors:

• white;
• turquoise;
• black;
• brown;
• pink;
• red;
• Violet;
• orange.

The most common phase colors are black, white and brown.

Despite its apparent simplicity, color coding has a number of features that raise the following questions for beginners:

1.What is PEN?

2. How to determine the phase, grounding and zero if the insulation has a non-standard color or is completely colorless?

Let's deal with each point.

What is PEN?

The TN-C type grounding system, which is outdated today, assumes the combination of grounding and neutral. Its main advantage is the speed of electrical work. The disadvantage of TN-C is the high probability of electric shock during wiring in an apartment or house.

The main color for designating a combined wire is yellow-green, but there is a blue color at the ends of the insulation, which is characteristic of neutral wire.

On the wiring diagram, such a contact is indicated by three Latin letters "PEN".

How to find phase, ground and zero?

There are cases when, when repairing a household electrical network, it turns out that all conductors have the same color. In this case, how to determine which wire is which.

In a single-phase network, where there are only two cores, without grounding, you just need to have a special indicator screwdriver with you. First you need to turn off the electricity at the switchboard. Then the wires are stripped and bred to the sides. Now we turn on the electricity again and alternately bring the indicator to each of the wires. If, upon contact, the light on the screwdriver lights up, then this is a phase, and the second core, therefore, zero.

If the electrical network is three-phase, then more sophisticated equipment is needed - a multimeter with measuring probes. First, set the device to a value above 220 volts. We fix one probe in phase, and the second we determine grounding and zero. Upon contact with zero, the tester should show a voltage of 220 volts. The ground wire will show a slightly lower voltage.

If you don’t have an indicator screwdriver or a multitester at hand, then you can determine the ownership of the wire by insulation. The important thing to know here is that the blue shell is always the neutral. Even in the most non-standard markings, its color does not change. The other two cores are more difficult to install.

The first way is based on associations. For example, you have a colored and white or black contact in front of you. Usually the earth is indicated in white or black. Therefore, the remaining wire is a phase.

The second way. We discard the neutral again. Left red and black. According to the PUE, white insulation is a phase. Then the red conductor is ground.

In circuits with direct current, the color marking of minus and plus is represented by black and red insulation, respectively. In a three-phase transformer network, each phase is painted in an individual color:

• A-yellow;
• B-green;
• S-red.

Zero, as always, is blue, and ground is yellow-green. In cables designed for a voltage of 380 volts, the wires are designated as follows:

• A-white;
• B-black;
• S-red.

The protective and neutral conductors do not differ in marking from the previous version.

We designate the wires ourselves

In the absence of a visual indication, after repair work you need to specify the ownership of the wires yourself. For this, a bright insulating tape or heat shrink tubing.

According to GOST, the marking of the cores must be carried out at the ends of the conductors - at the points of their contact with the bus.

Such notes will greatly facilitate future repairs and maintenance.

The vast majority of cables different colors lived insulation. This was done in accordance with GOST R 50462-2009, which establishes the l n marking standard in electrics (phase and neutral wires in electrical installations). Compliance with this rule guarantees fast and safe work masters at the big industrial facility, and also avoids electrical injury when self repair.

Variety of colors for electrical cable insulation

The color coding of wires is diverse and varies greatly for grounding, phase and neutral conductors. To avoid confusion PUE requirements regulate what color of the ground wire to use in the power panel, what colors must be used for zero and phase.

If a installation work carried out by a highly qualified electrician who knows modern standards for working with electrical wires, you do not have to resort to help indicator screwdriver or multimeter. The purpose of each cable core is deciphered by knowing its color designation.

Ground wire color

From 01/01/2011, the color of the ground (or neutral) conductor can only be yellow-green. This color marking of wires is also observed when drawing up diagrams on which such cores are signed in Latin letters PE. Not always on cables, the coloring of one of the cores is intended for grounding - usually it is done if there are three, five or more cores in the cable.

PEN-wires with combined "ground" and "zero" deserve special attention. Connections of this type are still often found in old buildings, in which electrification was carried out according to outdated standards and has not yet been updated. If the cable was laid according to the rules, then the blue color of the insulation was used, and yellow-green cambric was put on the ends and joints. Although, you can also find the color of the ground wire (grounding) exactly the opposite - yellow-green with blue tips.

The ground and neutral conductors may differ in thickness, often it is thinner than the phase ones, especially on cables that are used to connect portable devices.

Protective grounding is mandatory when laying lines in residential and industrial premises and is regulated by the PUE and GOST 18714-81 standards. The zero ground wire should have as little resistance as possible, the same applies to the ground loop. If all installation work is done correctly, then grounding will be a reliable protector of human life and health in the event of a power line malfunction. As a result, the correct marking of cables for grounding has crucial, and zeroing should not be applied at all. All new houses are wired according to the new rules, and the old ones are queued for replacement.

Colors for neutral wire

For "zero" (or zero working contact), only certain colors wires are also strictly defined by electrical standards. It can be blue, blue or blue with a white stripe, and regardless of the number of cores in the cable: a three-core wire in this regard will not differ in any way from a five-core one or with more large quantity conductors. In electrical circuits, “zero” corresponds to the Latin letter N - it participates in closing the power supply circuit, and in circuits it can be read as “minus” (phase, respectively, is “plus”).

Colors for phase conductors

These electrical wires require special care and "respectful" handling, as they are current-carrying, and careless contact can cause severe electric shock. The color marking of wires for connecting the phase is quite diverse - you cannot use only colors adjacent to blue, yellow and green. To some extent, it is much more convenient to remember what the color of the phase wire can be - NOT blue or blue, NOT yellow or green.

On electrical diagrams, the phase is denoted by the Latin letter L. The same marking is used on wires if color marking is not used on them. If the cable is designed to connect three phases, then the phase conductors are marked with the letter L with a number. For example, to draw up a diagram for a three-phase 380 V network, L1, L2, L3 were used. Even in electrics, an alternative designation is accepted: A, B, C.

Before starting work, you need to decide how the combination of wires will look in color and strictly adhere to the chosen color.

If this question was thought out at the stage preparatory work and taken into account when drawing up wiring diagrams, you should purchase required amount cables with conductors of the required colors. If, nevertheless, the desired wire is over, then you can mark the cores manually:

• ordinary cambric;
• shrink tubes;
• tape.

About wire color marking standards in Europe and Russia, see also in this video:

Manual color marking

It is used in cases where during installation it is necessary to use wires with conductors of the same color. It also often happens when working in old houses, in which the wiring was done long before the advent of standards.

Experienced electricians, so that there is no confusion during further maintenance of the electrical circuit, used kits that allow you to mark the phase wires. This is allowed and modern rules, because some cables are made without color-letter designations. The place of use of manual marking is regulated by the norms of the PUE, GOST and generally accepted recommendations. It is attached to the ends of the conductor, where it connects to the bus.

Marking two-wire wires

If the cable is already connected to the network, then to search phase wires in electricians, a special indicator screwdriver is used - in its case there is an LED that glows when the sting of the device touches the phase.

True, it will be effective only for two-wire wires, because if there are several phases, then it will not be able to determine where which indicator is. In this case, you will have to disconnect the wires and use a continuity.

Standards do not oblige to make such markings on electrical conductors along their entire length. It is allowed to mark it only at the joints and connections of the necessary contacts. Therefore, if it becomes necessary to apply labels on electrical cables without designations, you need to purchase materials in advance for marking them manually.

The number of colors used depends on the applied scheme, but main recommendation yet there is - it is desirable to use colors that exclude the possibility of confusion. Those. do not use blue, yellow or green labels for phase wires. In a single-phase network, for example, the phase is usually indicated in red.

Three-core wire marking

If you need to determine the phase, zero and ground in three-wire wires, then you can try to do this with a multimeter. The device is set to measure alternating voltage, and then gently touch the phase with the probes (it can also be found with an indicator screwdriver) and the two remaining wires in series. Next, you should remember the indicators and compare them with each other - the “phase-zero” combination usually shows a greater voltage than “phase-ground”.

When the phase, zero and earth are determined, then marking can be applied. According to the rules, a yellow-green colored wire is used for grounding, or rather a core with such a color, so it is marked with electrical tape suitable colors. Zero is marked, respectively, with blue electrical tape, and the phase is any other.

If, during preventive work, it turned out that the marking was outdated, it is not necessary to change the cables. Replacement, in accordance with modern standards, is subject only to electrical equipment that has failed.

As a result

Proper wiring is a must. quality installation electrical wiring during work of any complexity. It greatly facilitates both the installation itself and the subsequent maintenance of the electrical network. In order for electricians to “speak the same language”, mandatory standards for color-letter marking have been created, which are similar to each other even in different countries. In accordance with them, L is the designation of the phase, and N is zero.

There is a funny opinion among newbies in electrics, they say various colors cables and wires are just an advertising "chip" of manufacturing companies. Of course, this is not true. Conductors differing in color are needed for convenience - in order to immediately determine: where is the phase in the wiring, where is zero and where is the ground.

At the same time, incorrect connection of incompatible types of wires is fraught not only with a short circuit, but also with electric shock to a person.

The main task of the tsyetovoy is to ensure safe conditions for electrical work. Insulation colors that differ from each other can significantly reduce the time it takes to find and connect certain contacts.

If you look at the PUE or the same European standards, you can find out that each individual core has its own special color of the insulating layer. The main objective of this article is to help the reader understand: what color are the phase, zero and ground wires.

Appearance of the ground wire

According to the rules for the installation of electrical installations, insulating layer The ground wire must be colored yellow-green. Sometimes manufacturing companies also apply a green insulating layer with longitudinal and transverse yellow stripes to the wire. There are also shells entirely painted in yellow or green. On the wiring diagram, the “earth” is marked with the abbreviation “PE”. What is important - the ground wire can be called "zero protection" and do not confuse this definition with "neutral wire".

Example appearance"grounding":

Appearance of the neutral wire

Both in a single-phase and in a three-phase electrical network, the color marking of the neutral wire must always be blue or blue color. On the diagram, it is designated as "N". Also, zero is often called zero or neutral working contact.

An example of the appearance of "neutral":

The appearance of the wire "phase"

Unlike the previous versions of the conductors, the phase wire (aka “L”) can be painted in one of the following colors:

• black;
• white;
• grey;
• red;
• brown;
• orange;
• Violet;
• pink;
• turquoise.

It is worth noting that often the “phase” is black, white or Brown:

Important information

The color marking of electrical wires has many features. Often beginners are faced with huge amount various questions. The most frequent among them:

1. What does the abbreviation "PEN" mean?
2. How to determine where the ground, zero and phase are, if the wires do not differ in insulation colors or have a non-standard color?
3. How to specify zero, phase and ground yourself?
4. What other wire color coding standards might exist?

Well, let's find answers to these important questions together.

Abbreviation "PEN"

The system that has become irrelevant at the present time grounding TN-C involves connecting earth to neutral. This has its own plus, which is to increase the ease of installation work. However, it also has its drawback, namely, the risk of electric shock when installing wiring in a house or apartment. In this case, such a combined wire is painted yellow-green, but the ends of the insulation are blue (which is typical for neutral). Just this combined contact is indicated on the diagrams as "PEN":

Search for PE, L and N

Suppose, in the process of repairing an electrical network, you find that all the wires are painted the same color. How to figure out what each of the conductors means?

If a single-phase network does not imply the presence of grounding (there are only two wires in the network), then an indicator screwdriver is needed. It will help to determine which of the wires is “phase” and which is “zero”.

Before the procedure, do not forget to turn off the power supply at the input panel. Next, you will need to carefully strip both wires of the network and separate them away from each other, after which, turn on the current supply again. Now it remains to distinguish the “phase” from “zero” using the indicator: upon contact with the “phase” wire, the light on the screwdriver handle will light up (from which it follows that the second wire is the desired “zero”).

In the same situation, when the wiring also has a third ground wire, you need to use a multimeter. In short, it is applied as follows. To get started, set the AC measurement range on the device to above 220 volts. Next, lean one of the two tentacles against the phase core, and with the second tentacle, find “zero” / “ground”. In this case, in case of contact with the neutral conductor, the voltage value within 220 Volts will appear on the display of the multimeter. In the case of contact with the ground wire, the voltage will be slightly lower.

There is another way to determine the types of conductors. It will help you when there is neither an indicator screwdriver nor a multimeter at hand. The logic and color of the insulation will help out here. Remember that the blue shell is absolutely always "zero". Determining the remaining two wires will be a little more difficult. The first option is this: you are left with a colored and black / white contact, among which the colored one is most likely the “phase”, and the last white or black wire is the “ground”. A second scenario is also possible: you are left with a red and black / white wire, where white insulation (according to the PUE) means “phase”, and the remaining red one means “ground”.

Be careful! The described method is only advisory nature and is quite dangerous. In case you decide to use it, make appropriate notes for yourself that will save you from electric shock when replacing a chandelier or socket.

What else I would like to say is that in the chain direct current color marking of plus and minus is represented by black and red color of the insulating layer. In a three-phase network, each “phase” will have its own color (A is yellow, B is green, and C is red). In this case, “zero” will be blue, and “ground” will be yellow-green. In a 380 volt cable, wire A will be white, B will be black, and C will be red. Zero working and protective wires will be the same as in the previous version.

How to specify L, N and PE by yourself?

When the designation does not exist at all, or it is radically different from the standard one, it is recommended to designate all the elements on your own. Colored electrical tape or special heat shrink tubing (also known as cambric) will help in this matter. According to regulatory documents indication of the types of wires must be carried out at their ends - in those places where the conductors are connected to the bus:


The marks made will help in the future both the owner of the house or apartment, and the invited electrician. And this is really worth taking care of in advance.

Currently, the industry produces electrical wires different section with alphanumeric and color-coded cores along the entire length of the wire. The main function of any type of marking is the visual recognition of each individual wire core for its intended purpose, as well as facilitating (accelerating) the installation and operation of wires.

In addition, the division of cores by colors in the power electrical circuit- it is also one of modern requirements safety regulations, regulated by GOST.

electrical wire It is widely used in production and in everyday life both in AC power circuits (single-phase 220V network or three-phase 380V network) and in DC circuits. Electric wire is single-core and multi-core. The cores of the wire can be single-wire or multi-wire.

Single-phase two-wire network 220V

A two-wire electrical network is an electrical network with two electrical conductors. One conductor is phase, the second is zero. The two-wire electrical network is still found today in older homes in the form of conventional electrical wiring. old electrical wiring is a two-wire aluminum wire("noodles") with white insulation.

A two-wire wire is used to connect switches, conventional sockets, lamps.

Because since both cores of such a wire have the same color, it is rather problematic to visually distinguish the phase from zero. Therefore, in order to determine where the phase is and where it is zero, they use an indicator screwdriver, a probe, a “continuity”, a tester, a multimeter or other electrical measuring device.

Today, in order to distinguish the phase from zero during operation, either a two-core wire with cores is used during installation different color, or two single-core wires.

As a two-core wire, a flexible wire with a brown and blue (light blue, blue) core is often used. It is strongly recommended to use a brown conductor as a phase conductor, and a conductor as a neutral conductor. of blue color.

Often there are two-core wires with a different color of the cores. For example, in such wires, the phase wire may not be brown, but red, black, gray or another color.

In the case of using two separate solid wires, there are two marking options. The first is the use of wires of different colors. For example, you can use a red wire as a phase, and a blue wire as a zero.

If wires of the same color are used, then the phase and neutral cores can be marked either with colored electrical tape or by using colored heat shrink tubing. When using colored electrical tape, red electrical tape is wound on the phase wire at the beginning and at the end, and blue electrical tape is wound on the neutral wire.

When using heat shrink, marking single-color wires is almost the same as marking with electrical tape. Red heat shrink is put on the phase wire, and blue heat shrink is put on the neutral wire.

At home, you can mark wire cores with other colors.

Color marking in a single-phase three-wire network 220V

A three-wire electrical network is a network with three electrical conductors. Currently, a three-wire network is becoming more and more common, especially for new wiring.

As in a two-wire network, one conductor is phase, the second is zero, but the third conductor is a protective ground wire that serves to protect against electric shock. In a three-wire network, a three-wire wire is used, usually with a brown, blue and yellow-green core.

The brown wire is a phase, the blue wire is the neutral conductor, the yellow-green wire is the conductor protective earth. To avoid confusion, it is not recommended to use a core with a yellow-green color as a phase or neutral conductor.

A three-core wire with colored wires is used to connect modern European-style sockets that, in addition to phase and zero contacts, also have a contact for connecting a ground conductor. Three-wire wires are also used to connect fixtures.

Color designations of wires in a three-phase network 380V

A three-phase electrical network can be four-wire or five-wire, i.e. with four or five wire cores. The only difference is the presence or absence of a protective earth conductor. Those. a four-wire network is three phase conductors, a zero working conductor and the absence of a protective earth conductor. A five-wire network consists of three phase conductors, a zero working conductor and the presence of a ground conductor.

In both the four-wire and five-wire networks, a blue conductor is used for the zero working conductor, and a yellow-green conductor is used for the ground conductor. As for the three phases A, B and C, the brown, black and gray cores are most often used for them, respectively. But there are also other colors of wire cores.

A four-core and five-core wire is used to connect a three-phase load or to separate a single-phase load into groups.

DC network

In a DC electrical network, two conductors are usually used. The first conductor is the plus and the second conductor is the minus. The red conductor is used as the positive conductor, and the blue conductor is used as the negative conductor.

As a result of all of the above, it is worth noting the following: despite certain standard requirements according to the color marking of wires, it is not recommended to rely on the color of one or another wire core without a preliminary check.

Separate wire-cores that make up electrical cables, have insulation of certain colors. GOST R 50462-2009 regulates the color of insulation, this document shows the features of n and l marking in electrics in order to simplify the work of craftsmen at large facilities and ensure safety during the repair process. Those who decide to repair electrical appliances on their own or do other similar work should also know what color the ground, phase and zero wires are.

Features of the color of the cores

To avoid errors, the requirements of the PUE describe the colors of all the main electrical wires. If an experienced electrician was engaged in commissioning work, following the rules of the PUE and the corresponding GOSTs, for self-repair, neither an indicator screwdriver nor other devices that determine the purpose of a particular core will be needed.

Color marking in electrics according to GOST

grounding

The yellow/green wire is ground. AT circuit diagrams neutral conductors are marked with the letters PE. In some houses of old buildings, there are PEN wires in which grounding is combined with a zero core. If the cable was pulled according to the rules, wires with blue insulation were selected, and only the ends and places of twists were yellow-green (thermotubes were put on them). The thickness of the "zero" and grounding can be different. Often the thickness of these two cores is less than the thickness of the phase core, this occurs when connecting portable devices.

When it comes to wiring high-rise buildings and in industrial premises, come into force PUE norms and GOST 18714-81, which prescribe the mandatory arrangement of protective grounding. Grounding must have a minimum resistance in order to compensate for the consequences of faults on the line and prevent harm to human health. That is, compliance with the color marking standards for PUE wires is of paramount importance.

"Zero"

What color is the neutral wire? Electrical standards dictate that its insulation may be blue, blue with a white stripe, or light blue. Such a marking will be present in a cable with any number of cores. In circuit diagrams, "zero" is marked with the letter N, the circuit is closed on it. Sometimes it is called "minus", and phase - "plus".

"Phase"

The color of the phase is something that is of paramount importance for an electrician: handling conductors requires care and knowledge. The slightest touch of the phase can lead to injury. There are a lot of colors for phase wires marked in the form of the letter L in the wiring, the ban applies only to the use of blue, yellow and green colors. If the cable is three-phase, the serial number of the core is added to the letter L.

When a single-phase circuit is separated from a three-phase circuit, electricians use cables with exactly the same color, watching the color of the phase and zero in the wire. Before starting work, they determine for themselves how different cores will be connected, and in the future they follow the chosen color. Sometimes thermocambrics are fused on them or several turns of colored corresponding electrical tape are wound.

According to GOST:

• black phase wires are used in power circuits operating with direct and alternating current;
• red color - used in control circuits designed for alternating current;
• with Orange color- meet with interlock control circuits powered from external sources.

How to determine the purpose of the wire - neutral or ground?

L N marking in electrics is not always observed in old buildings, so the question arises of independently distinguishing between the neutral wire and the ground wire. When the circuit is closed, "zero" passes electricity. The grounding wire has only a protective function, and in the "normal" mode, the current does not flow through it.

You can find out whether it is “zero” or “ground” like this:

• Use an ohmmeter, having previously turned off the voltage between the measuring points. On the ground wire, the resistance will not exceed 4 ohms.
• Use a voltmeter and measure the voltage between the "phase" and other wires in series (the method is suitable for three-core cables). The ground wire will give the highest value.
• If the colors of the “phase”, “zero” and “ground” wires are unknown, and you need to find out the voltage between the ground wire and some obviously grounded object (for example, a heating radiator), a voltmeter will also come in handy. True, when connecting the "ground" and a grounded object, it will not show anything. But a small voltage will be reflected on its indicator if you do the same with the "zero" wire.

In a two-core cable, only the phase and neutral wires will always be present.

What to do if all the cores in the cable have the same color insulation

The question of marking wires by color does not make sense when you have to work with single-color wires - for example, when repairing wiring in old houses. For such cases, there are kits that make it possible to mark the cores. Areas for fixing marking devices are prescribed by the requirements of GOST, usually they are fixed next to the connection to the bus.

How to mark a wire with two cores

If all the wires in the cable have the same insulation, and the appliance is already connected to the network, the masters use indicator screwdrivers. The latter glow when the metal part touches phase wire. To mark a two-core cable, in addition to such a screwdriver, you will need thermocambrics or multi-colored electrical tape. The designation of colors will be made only at the joints - it is not necessary to wrap the core with colored tubes or electrical tape along the entire length.

Probe screwdriver-indicator

Phase wires can be marked with any color except blue, yellow and green. If a two-core cable is connected to a single-phase network, it is customary to mark the phase wire in red.

How to mark a wire with three cores

What is the color of the ground wire in a three-wire wire? If the answer to the question is not immediately determined, all the insulation on the cores of the same color will help out the multimeter. The device is set to alternating current, and the master sequentially touches both probes first with the phase wire, then with the rest of the wires, memorizing the indicators. Touching phase and zero will give more voltage than touching phase and ground.

What color is the ground wire? It has a yellow-green color. It is this thermocambric or electrical tape that must be used to mark the "earth" in a three-core cable. On the “zero” - a blue tape should be wound, on the phase - not blue and not yellow-green thermocambric.

Letter designation of phase, zero and ground

Usage different colors wires in electrical wiring is a convenient and logical measure that simplifies repair and installation work. If wires with multi-colored conductors are laid in the house, during the repair you will not have to spend time “ringing” each of them, and, for example, a break in the phase conductor will be detected quickly. The presence of a phase and zero also matters, but working with letters and numbers is still longer than with color: just look at the cable and the purpose of the wires immediately becomes clear.