The basics of the craft for a novice electrician: the color of the wires, phase, zero, earth - what each of them means. Color of wires according to purpose: phase, zero and "earth" Yellow wire in electrics

Electric current is especially dangerous for humans, besides it is not visible. When installing wiring, wires of different colors are used for safe and fast work, letters and numbers indicate the cross section of the wire. Color and symbol designations or, in other words, markings are prescribed in the standards, you should not violate them so as not to endanger your own and others' lives.

Core insulation color code

Visually, the wires differ from each other not only in color and diameter, but also in the number and type of cores. Depending on this characteristic, single-core and multi-core electric wires are distinguished. Their diversity finds its application in AC circuits both in industrial three-phase networks with a voltage of 380V, and in a single-phase home network of 220V. DC power circuits use the same electrical wire standard.

Single-phase two-wire network 220V

Such a network includes an outdated type of wiring, where aluminum wires in a single white braid are used as cores, popularly known as “noodles”. One core of an electric wire is a phase conductor, the second core is a zero one. A single-phase two-wire network is used for ordinary household needs: simple sockets and switches.

How to properly equip the house electrical network,.

The problem with the installation of single-color wiring is the difficulty in determining the phase and neutral wires. The presence of additional measuring equipment will help to cope with the task, you can use a multimeter or a special screwdriver with an indicator, a probe, a tester, a "continuity".

The design of a single-phase two-wire network is allowed by GOST for premises with a small load on the electrical network and low safety requirements. In such cases, two single-core wires or one two-core wire with wires of different colors are used.

In the case of using a solid wire, one core is brown, the other is blue or blue. According to the generally accepted marking, the brown core is the phase, and the blue one is the neutral conductor, it is strictly not recommended to violate this order. In practice, there are phase wires other than brown: black, gray, red, turquoise, white, pink, orange, but not blue.

The use of two independent solid wires also requires marking. You can use a colored wire along the entire length, for example, blue for zero, red for phase. It is permissible to mark wires of the same color with electrical tape or heat shrink tubes of different colors, placing the marking at both ends of each core.

The use of the tube does not involve wrapping the ends, but putting it on the wire and exposing it to hot air in order to fix the heat shrink on the wire. For home use, you can use any color of marking materials that are accessible and understandable to the wiring installer.

Single-phase three-wire network 220V and the marking used in it

Modern requirements for the installation of electrical wiring dictate the presence of a third wire - grounding. This is the difference and the main advantage of a single-phase three-wire network.

Three electrical conductors perform the corresponding functions: phase, zero and ground, protection against injury by alternating current. The marking of the phase wire remains brown, zero - blue or blue, and the ground wire must be used in a yellow-green braid.

Household appliances that comply with European safety standards require connection to sockets with grounding. Such sockets have a special contact to which a yellow-green wire is connected. It is strictly not recommended to use this color to mark the wire phase and zero in order to avoid possible unpleasant consequences.

Three-phase network 380V

A three-phase network, like a single-phase network, can be with or without grounding. Depending on this, a three-phase four-wire electrical network with a voltage of 380V and a three-phase five-wire network are divided.

A four-wire network consists of three phase conductors and one neutral working conductor; there is no protective earth conductor here. In a five-wire network, in addition to three phase conductors and one zero, there is also a ground conductor.

Similarly with two-phase marking of cores, a blue or blue core is used for the neutral conductor, yellow-green for the ground conductor. Phase A is marked in brown, phase B is black, and phase C is marked in grey. There may be exceptions to the rules for phase conductors, their color marking allows the use of other colors, but not blue and yellow-green, which already have their own function.

Single-phase load grouping or three-phase load connection uses four-core and five-core wires.

DC network

A DC network differs from an AC network in that it contains two conductors: plus and minus. The positive conductor conductor is marked in red, and the negative conductor conductor is marked in blue.

The practice of color separation of wires is familiar to professionals and amateurs in their field, is actively used in electrics, but still you should not blindly trust the markings. Safety with a measuring device is a deliberate and balanced move when installing electrical networks, you should not neglect it.

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In electrical installations and household electrical networks, conductors are used for various purposes. The main ones used for the transmission of electrical energy are phase voltage conductors, zero working and zero protective.

All of them must be identified. Otherwise, even if there are circuit, wiring or single-line diagrams explaining which contacts of electrical devices they are connected to, it will be impossible to figure it out. And the need for this arises constantly.

Another important reason requiring the identification of conductors is electrical safety. Touching any live parts, even those not under a life-threatening potential, is prohibited without checking the absence of voltage on them. But sections of the circuit containing both dangerous and safe potentials must be clearly marked. This is one of the many components of the organization of the safe operation of electrical installations.

Identification of conductors of power electrical circuits is carried out by two methods:

• conductors are painted in colors corresponding to their purpose;
• at the ends of the conductors or along their entire length, letter designations are applied that unambiguously determine the functional purpose.

The rules for applying color and letter marking to conductors used in power electrical circuits are detailed in GOST R 50462-2009. Despite the fact that it has the status of the national standard of the Russian Federation, it completely repeats the IEC 60446-2007 standard. Thus, the rules for marking wires in Russia are brought into line with European standards. The relevance of this is dictated by the fact that Western equipment is supplied to Russia, manufactured according to European standards, and therefore, for its proper operation, our own rules must be brought into line with IEC.

So, now let's figure out what colors the wires and cable cores are for use in various circuits.

Marking of phase conductors

All electrical networks can be divided into:

• single-phase;
• three-phase;
• DC networks.

Each of them has its own rules for marking conductors. Let's start with phase.

In single-phase circuits, all phase conductors according to GOST must be brown. However, this does not mean at all that such wires should be used when installing a single-phase switchboard. Their color may not necessarily be brown, but any, but not blue or yellow-green. Additionally, the ends of the conductors can be marked with the letter L1, L2 or L3, indicating which phase of the three-phase network this shield is connected to.

However, if this single-phase circuit branches off from a three-phase one as part of a device or shield, then the color of its conductors must match the color of the wires of the phase to which it is connected: brown, black or gray.

Brown, blue and yellow-green colors are used for the cores of cables intended for the installation of single-phase networks.

Phase wires in three-phase networks were previously marked with letters: A, B and C. In addition, tires were painted in the appropriate colors for identification:

• phase A - yellow;
• phase B - green;
• phase C - red.

Now GOST prohibits the use of green and yellow for marking, as they can be confused with yellow-green, which has a different purpose, which will be discussed later.

It was not customary to mark the wires at all. A good example of this is the access switchboards. All the wires in them: both phase and zero are the same. An attempt to determine their purpose is fraught with some difficulties: after all, even to conclude that the conductor is connected to the phase of the mains, it is possible with certainty only when there is voltage on it, and you have an indicator in your hands. You can never be sure that the conductor is zero.

Therefore, GOST for phase conductors prescribes the following marking.

phase wire	Letter	Colour
Phase A (Phase 1)	L1	brown
Phase B (phase 2)	L2	black
Phase C (Phase 2)	L3	grey

It is allowed to mark wires in any of two ways or both at once. In the first case, tags with a letter designation are attached to the ends of the wires, in the second, the corresponding coloring of the current-carrying parts is used. Strictly speaking, it is not at all necessary to use wires that have brown, black and gray colors in switchboards during installation. Color binding is more relevant for cable lines, as their cores are painted in brown, black, gray, blue and yellow-green. When connecting cables to terminal blocks, consumers or to the outputs of electrical devices, it is necessary to comply with the requirements of GOST.

For the assembly of panel products, the installation of phase circuits is allowed to be carried out with single-color wires, while observing the conditions:

• blue color cannot be used;
• yellow-green color cannot be used;
• marking with letters applied to the beginning and end of the wire is required.

Western manufacturers do not paint tires in brown, black, gray, as well as blue and yellow-green, marking them with letter markings. At the same time, the cost of assembling panel products and complete switchgears is slightly reduced. But in return, there is a drawback: in order to find out the purpose of the tire, you need to find the nearest marking plate on it or use the knowledge of the Electrical Installation Code, which indicates the requirements for the relative position of the tires. But there are electrical installations in which the phase sequence cannot comply with the PUE. Therefore, when marking tires, it is necessary to stick the plates as often as possible. GOST prescribes marking at least twice within a panel or shield: at the bus inlet to the panel and at the output, or at its beginning and end.

Marking conductors "ground" and zero

Here, the labeling requirements are much more stringent, as this is directly related to electrical safety.

Protective zero (or ground), as well as live parts intended for the potential equalization system, are marked with alternating yellow and green stripes. For tires, this is a uniform alternation of yellow and green stripes, while wires and cable cores are colored appropriately at the factory.

It is prohibited to use yellow-green, as well as blue for marking other circuits, as well as marking the protective zero with other colors.

For the letter marking of the “ground” wire, the designation PE is provided, for the potential equalization conductor - GNYE.

Working zero is marked using only blue. Other markings, as well as the use of blue for other purposes, are prohibited. Working zero is denoted by the letter N.

It is a little more difficult to mark the zero combined, which is assigned the designation PEN. Since it combines the functions of a ground conductor and a working zero, this is also taken into account when marking. It is permissible to use two methods similar to each other: either take a wire that has a blue color and apply yellow-green markings at its ends, or apply blue markings at the ends of a yellow-green wire. This can be done either with insulating tape or heat shrink tubing.

Busbars for identification do not need to be painted over the entire length, since this method is difficult for these chains. On the tires designed to connect the conductors "ground" and zero, many holes are made for their connection, which makes solid coloring difficult, and at times impossible. It is allowed to apply colored stripes that have blue or yellow-green colors along the edges of the tire.

Anyone who has ever dealt with wires and electrics noticed that conductors always have a different color of insulation. It's not just done. The colors of the wires in electrics are designed to make it easier to recognize the phase, neutral wire and ground. All of them have a certain color and are easily distinguished during operation. What is the color of the wires phase, zero, ground and will be discussed further.

How phase wires are painted

When working with wiring, the phase wires are the most dangerous. Touching the phase, under certain circumstances, can become lethal, which is probably why bright colors are chosen for them. In general, the colors of wires in electrics allow you to quickly determine which of the wire bundles are the most dangerous and work with them very carefully.

Most often, phase conductors are red or black, but there is also another color: brown, lilac, orange, pink, purple, white, gray. Here in all these colors phases can be painted. It will be easier to deal with them if we exclude the neutral wire and ground.

In the diagrams, phase wires are indicated by the Latin (English) letter L. If there are several phases, a numerical designation is added to the letter: L1, L2, L3 for a three-phase 380 V network. In another version, the first phase is indicated by the letter A, the second - B, the third - C .

Ground wire color

By modern standards, the ground conductor is yellow-green. It usually looks like yellow insulation with one or two longitudinal bright green stripes. But there are also coloring of transverse yellow-green stripes.

In some cases, only yellow or bright green conductors may be in the cable. In this case, the "earth" has exactly this color. It is displayed in the same colors on the diagrams - more often bright green, but it can also be yellow. Signed on the diagrams or on the equipment "earth" in Latin (English) letters PE. The contacts to which the "earth" wire must be connected are also marked.

Sometimes professionals call the ground wire "zero protective", but do not confuse. It is earth, and it is protective because it reduces the risk of electric shock.

What color is the neutral wire

Zero or neutral is blue or blue, sometimes blue with a white stripe. Other colors in electrics are not used to indicate zero. So it will be in any cable: three-core, five-core or with a large number of conductors.

In blue, they usually draw "zero" on the diagrams, and sign it with the Latin letter N. Experts call it the working zero, since, unlike grounding, it participates in the formation of the power supply circuit. When reading a circuit, it is often defined as "minus", while the phase is considered "plus".

How to check the correct marking and wiring

The colors of wires in electrics are designed to speed up the identification of conductors, but relying only on colors is dangerous - they could be connected incorrectly. Therefore, before starting work, it is worth making sure that you have correctly identified their belonging.

We take a multimeter and / or an indicator screwdriver. It is easy to work with a screwdriver: when you touch the phase, the LED mounted in the case lights up. So it will be easy to determine the phase conductors. If the cable is two-core, there are no problems - the second conductor is zero. But if the wire is three-core, you need a multimeter or tester - with their help we will determine which of the remaining two phases, which is zero.

We set the switch on the device so that the jackal is more than 220 V. Then we take two probes, hold them by the plastic handles, gently touch the metal rod of one probe to the found phase wire, the second to the supposed zero. The screen should show 220 V or the current voltage. In fact, it can be much lower - these are our realities.

If 220 V or a little more is displayed, this is zero, and the other wire is presumably “ground”. If the value is less, we continue the check. With one probe, we again touch the phase, with the second - to the intended ground. If the meter reading is lower than the first measurement, you have the "ground" in front of you and it should be green. If the readings turned out to be higher, then somewhere they messed up with and in front of you “zero”. In such a situation, there are two options: look for exactly where the wires were connected incorrectly (preferably) or simply move on, remembering or noting the existing situation.

So, remember that when the phase-zero pair rings, the multimeter readings are always higher than when the phase-ground pair rings.

And, in conclusion, let me give you advice: when laying wiring and connecting wires, always connect conductors of the same color, do not confuse them. This can lead to disastrous results - at best, to the failure of the equipment, but there may be injuries and fires.

Carrying out electrical work is almost impossible without the presence of cables with insulation of different shades. This is not a manufacturer's advertising move or a fashion trend, but a necessity for professional electricians.

According to the requirements, the color of the wires: phase zero earth must be different from each other and have an appropriate option.

In contact with

The concepts of phase, zero and ground

To answer the question: “Phase, zero, earth - what is it?”, You need to understand how the wiring is connected in the house. Electricity enters the housing from a transformer distributor. Zero is a wire connected to the ground loop at the substation. It is needed to create a load on the phase that is connected to the other end of the transformer winding. Grounding is not included in the power circuit, it provides protection in case of an accident.

The use of insulation of different shades makes it possible to determine whether the wires belong to a certain group.

In addition, this eliminates errors during the installation of electricians, which will protect against short circuits and electric shocks during network repairs.

The choice of wire colors in a three-core cable is carried out according to a single standard.

The cores have letter and color designations. Most often, insulation of a certain shade of the entire wire is used, sometimes you can specify a certain color on the connections and its ends.

This is done using multi-colored electrical tape or a special tube. To do everything right, you need to know how the phase and zero are indicated.

Varieties of shades of insulation

To make it convenient for electricians to work and not have to constantly check where the phase is and where– zero using special testers, and some rules have been adopted for the designation of phase and zero (PUE).

How do phase wires differ in color

According to the accepted standard, phase cores come in the following shades:

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

Important! The wires, which are marked with the letters L, N, in the electrician belong to the phase and zero, respectively, the protection core is signed by PE.

If a single-phase network is a branch of a three-phase circuit, then the color of the core insulation must be the same as that of the conductor to which it is connected.

An important point is the obligatory mismatch of the colors of the phase designation with the tone of grounding and zero.

Attention! If a cable is used that does not have markings, multi-colored marks are placed on it at the junctions and at the ends.

It is advisable, when laying wiring throughout the apartment, to use the same cable so that the colors of the wires in the electrician are the same everywhere.

The color of the working zero and ground

The color of the neutral wire is usually blue, and the protective earth conductor is made in yellow-green color with stripes that are applied longitudinally or transversely. If the functions of the neutral and protective conductor are combined, then its color is blue with yellow-green stripes at the junctions.

If you do not know what color the phase is, in order to determine if the conductors are connected correctly, you need to determine the phase and neutral wire: this will require special tools.

This is the easiest option for finding the phase. Without an indicator screwdriver, you should not start replacing fixtures, installing switches or sockets.

It is very easy to work with the tool. You need to touch the wire with a screwdriver, and if it is energized, then when you press the contact on the back of the tool, the lamp will light up.

A light signal means that a phase has been detected. This is the easiest and often recommended by electricians way to find the phase wire. The cost of a screwdriver is low, so anyone can afford to have one. However, there are drawbacks, for example, it can show voltage where it is absent.

The multimeter does not have a separate special mode that will help determine the phase or zero: you can find out only by the presence of numbers on the display or their absence.

When measuring the mains voltage with the tester, you need to select the mode for determining the voltage in the variable network. Before proceeding with the determination of the phase, check the device on any working outlet. After that, you can search for the phase with a red probe. If, having installed it on the phase, you start touching the rest of the wires with another probe, you will find zero (the device will show 220V) or ground.

But it will be difficult to establish where the ground is and where the zero is. If it is necessary to do this, then it is worth disconnecting the ground wire on the electrical panel, then when checking with the device, it will not show 220V on this conductor.

Multimeters modern industry produces two types: analog and digital. Each of them has its own advantages and disadvantages.

For example, analog instruments will help you make measurements in the presence of noise and waves. The digital device is used more often, it is used by construction organizations and manufacturers of radio equipment.

In everyday life, digital models of appliances are also more common.

If we talk about the technical characteristics of the multimeter, then digital models have more accurate measurement readings, but they differ significantly in cost, which depends on the built-in functions of the equipment. The indicator can be digital or pointer, the latter is considered more accurate. There are options that can be connected to a computer for data transfer.

Attention! In order for the device to serve for a long time, it is worth paying attention to its manufacture. The housing must be protected from shock and moisture penetration. It is better if the set includes a special case for storing and carrying equipment.

If the rules for color-coding wires were not used when creating the electrical wiring in the house, then it is difficult for other electricians to work with such a network. It will be necessary to check the phase and zero only with the help of special instruments.

If it is not possible to purchase wires of the appropriate shades during the network installation, then the connections can be marked with colored tape. This is allowed by the rules. In addition, during installation, you should adhere to the following recommendations:

• It is worth choosing cables from one manufacturer: in this case, the colors of the cores will be identical, this will eliminate errors when working with them;
• If you still had to use products from different manufacturers or different shades, then it is worth marking the cores with electrical tape of the appropriate colors. Do not rely on memory, so as not to guess later whether the blue wire is a phase or zero.
• If you had to lengthen the cable, take wires with the same color options as on the main one.
• Do not use cables without grounding (yellow-green core).

By applying these simple tips, you can avoid mistakes when creating electrical wiring or repairing it. This will keep you out of trouble. If another electrician has to maintain or repair the network, he will quickly figure it out, and he will not have to check each wire with instruments.

To facilitate the installation of electrical wiring, the cables are made with multi-colored wire markings. Installation of a lighting network and power supply to sockets involves the use of a cable with three wires.

The use of this color system significantly reduces the time for repairs, connecting sockets and. Also, this scheme minimizes the requirements for the qualification of the installer. This means that almost any adult man is able to carry out, for example, the installation of a lamp.

In this article, we will look at how ground, zero and phase are designated. As well as other color markings of wires.

Ground Color

The color of the ground wire, "ground" - almost always marked in yellow-green, less often there are windings both completely yellow and light green. The wire may be marked "PE". You can also find green-yellow wires marked "PEN" and with a blue braid at the ends of the wire at the attachment points - this is grounding combined with neutral.

In the switchboard (RSH) it is worth connecting to the ground bus, to the body and the metal door of the shield. As for the junction box, there the connection goes to the ground wires from the lamps and from the ground contacts of the sockets. The "ground" wire does not need to be connected to the RCD (residual current device), in connection with this, the RCD is installed in houses and apartments, since usually the wiring is done with only two wires. Grounding designation on the diagrams:

Conventional ground(1) Clear ground(2) Safety ground(3) Chassis ground(4) DC ground(5)

Color zero, neutral

Zero wire - must be of blue color. In the switchboard, it must be connected to the zero bus, which is indicated by the Latin letter N. All blue wires must be connected to it. The bus is connected to the input by means of a meter or directly, without additional installation of the machine. In the distribution box, all wires (except for the wire from the switch) of blue color (neutral) are connected and do not participate in switching. To the sockets, the blue “zero” wires are connected to the contact, which is indicated by the letter N, which is marked on the back of the sockets.

Phase color

The designation of the phase wire is not so clear. It can be either brown, or black, or red, or other colors. Besides blue, green and yellow. In the apartment switchboard, the phase wire coming from the load consumer is connected to the lower contact of the circuit breaker or to the RCD. In the switches, the phase wire is switched, during shutdown, the contact closes and voltage is supplied to consumers. In phase sockets, the black wire must be connected to the contact, which is marked with the letter L.

How to find ground, neutral and phase in the absence of a designation

If there is no color marking of the wires, then it is possible to determine the phase, upon contact with it, the screwdriver indicator will light up, but not on the neutral and ground wires. You can use a multimeter to find ground and neutral. We find the phase with a screwdriver, fix one contact of the multimeter on it and “probe” the other contact of the wire, if the multimeter showed 220 volts, this is neutral, if the values ​​\u200b\u200bare below 220, then grounding.

Letter and number wire markings

The first letter "A" denotes aluminum as the core material, in the absence of this letter, the core is copper.

The letters "AA" denote a multi-core cable with an aluminum core and an additional braid of it.

"AC" is indicated in the case of an additional lead braid.

The letter "B" is present if the cable is waterproof and it has an additional double-layer steel braid.

"Bn" cable braid does not support combustion.

"B" PVC sheath.

"G" does not have a protective shell.

"g" (lowercase) naked waterproof.

"K" control cable wrapped with wire under the top sheath.

"R" rubber sheath.

"HP" non-flammable rubber sheath.

Wire colors abroad

The color marking of wires in Ukraine, Russia, Belarus, Singapore, Kazakhstan, China, Hong Kong and in the countries of the European Union is the same: Ground wire - Green-yellow

Neutral wire - blue

phases are marked with different colors

The neutral designation is black in South Africa, India, Pakistan, England, but this is the case with old wiring.

currently neutral blue.

In Australia, it can be blue and black.

In the USA and Canada it is designated as white. Also in the USA you can find gray markings.

The ground wire is yellow, green, yellow-green everywhere, and in some countries it may be without insulation.

Other wire colors are used for phases and may be different, except for the colors indicating other wires.