Designation 0 and phase. Schematic designation of phase and zero in English. Separate color for the neutral wire and a variety of colors for the phase wire

In most modern cables, the conductors are insulated different colors. These colors have a certain meaning and are chosen for a reason. What is color marking of wires and how to use it to determine where the zero and ground are, and where the phase is, and we will talk further.

In electrical engineering, it is customary to distinguish wires by color. This makes the work much easier and faster: you see a set of wires of different colors and, based on the color, you can guess which one is intended for what. But, if the wiring is not factory-made and you did not do it, before starting work you should definitely check whether the colors correspond to the intended purpose.

To do this, take a multimeter or tester, check the presence of voltage on each conductor, its magnitude and polarity (this is when checking the power supply network) or simply call where and where the wires come from and whether the color changes “along the way.” So knowing the color coding of wires is one of the essential skills of a home craftsman.

Ground wire color coding

According to the latest rules, wiring in a house or apartment must be grounded. Last years all household and construction equipment Available with a grounding wire. Moreover, the factory warranty is maintained only if the power supply is supplied with a working grounding.

To avoid confusion, it is customary to use a yellow-green color for the ground wire. The hard solid wire has a green base color with a yellow stripe, while the soft stranded wire has a base color yellow color with a green longitudinal stripe. Occasionally there may be specimens with horizontal stripes or just green, but this is not standard.

Ground wire color - single-core and stranded

Sometimes the cable only has a bright green or yellow wire. In this case, they are used as “earthen”. On diagrams, “ground” is usually drawn green. On the equipment, the corresponding contacts are signed in Latin letters PE or in the Russian version they write “earth”. A graphic image is often added to the inscriptions (in the figure below).

In some cases, in the diagrams, the ground bus and the connection to it are indicated in green

Neutral color

Another conductor that is highlighted in a certain color is neutral or “zero”. The color blue is allocated for it (bright blue or dark blue, occasionally blue). On color diagrams, this circuit is also drawn in blue and signed with the Latin letter N. The contacts to which the neutral must be connected are also signed.

Neutral color - blue or light blue

In cables with flexible stranded wires, as a rule, is used more light shades, and single-core rigid conductors have a sheath of darker, richer tones.

Coloring phase

With phase conductors it is somewhat more complicated. They are painted in different colors. Already used ones - green, yellow and blue - are excluded, and all others can be present. When working with these wires, you need to be especially careful and attentive, because they are the ones where voltage is present.

Color coding wires: what color is the phase - possible options

So, the most common color markings for phase wires are red, white and black. There may also be brown, turquoise orange, pink, purple, gray.

On diagrams and terminals, phase wires are signed with the Latin letter L; in multiphase networks, the phase number is next to it (L1, L2, L3). On cables with several phases, they have different colors. This makes wiring easier.

How to determine if the wires are connected correctly

When trying to install an additional outlet, connect a chandelier, or household appliances, you need to know which wire is phase, which is neutral, and which is ground. If the connection is incorrect, the equipment will fail, and careless touching of live wires can end sadly.

You need to make sure that the colors of the wires - ground, phase, zero - match their wiring

The easiest way to navigate is by color coding of the wires. But things are not always simple. Firstly, in old houses the wiring is usually monochromatic - two or three white or black wires stick out. In this case, you need to understand it specifically, and then hang tags or leave colored marks. Secondly, even if the conductors in the cable are painted in different colors, and you can visually find the neutral and ground, you need to check the correctness of your assumptions. It happens that during installation the colors are mixed up. Therefore, first we double-check the correctness of the assumptions, then we begin work.

To check you will need special tools or measuring instruments:

• indicator screwdriver;
• multimeter or tester.

Find phase wire possible using indicator screwdriver, to determine zero and neutral you will need a tester or multimeter.

Checking with indicator

Indicator screwdrivers come in several types. There are models on which the LED lights up when a metal part touches live parts. In other models, checking requires an additional button press. In any case, when voltage is present, the LED lights up.

Using an indicator screwdriver you can find the phases. Metal part touch the exposed conductor (press the button if necessary) and see if the LED lights up. Lit - this is a phase. Does not light - neutral or ground.

We work carefully, with one hand. Second to the walls or metal objects(pipes, for example) we don’t touch. If the wires in the cable you are testing are long and flexible, you can hold the insulation with your other hand (stay away from bare ends).

Checking with a multimeter or tester

We set the scale on the device, which is slightly higher than the expected voltage in the network, and connect the probes. If we call the household single-phase network 220V, set the switch to the 250V position. With one probe we touch the exposed part of the phase wire, with the second - to the supposed neutral ( of blue color). If at the same time the arrow on the device deviates (remember its position) or a number close to 220 V lights up on the indicator. We perform the same operation with the second conductor - which is identified by its color as “ground”. If everything is correct, the readings of the device should be lower - less than those that were before.

If there is no color marking of the wires, you will have to go through all the pairs, determining the purpose of the conductors according to the indications. We use the same rule: when testing a phase-ground pair, the readings are lower than when testing a phase-zero pair.

World manufacturers household appliances When assembling their equipment, they use color coding for the mounting wires. It represents the designation in electrics L and N. Thanks to a strictly defined color, the master can quickly determine which of the wires is phase, neutral or ground. This is important when connecting or disconnecting equipment from power.

Types of wires

When connecting electrical equipment, installing various systems you cannot do without special conductors. They are made of aluminum or copper. These materials conduct electricity well.

Important! Aluminum wires must only be connected to aluminum wires. They are chemically active. If they are connected to copper, the current transmission circuit will quickly collapse. They are usually connected using nuts and bolts. Copper - through a terminal. It is worth considering that the latter type of conductors has significant drawback- oxidizes quickly when exposed to air.

Advice in case the current stops flowing at the site of oxidation: To restore the power supply, the wire must be insulated from external influences using electrical tape.

Wire classification

The conductor consists of one uninsulated or one or more insulated conductors. The second type of conductors is covered with a special non-metallic sheath. This can be a winding with insulating tape or a braid made of fibrous raw materials. Bare wires have no protective coatings. They are used in the construction of power lines.

Based on the above, we conclude that the wires are:

• protected;
• unprotected;
• power;
• installation.

They must be used strictly for their intended purpose. The slightest deviation from operating requirements leads to a breakdown of the power supply network. As a result of the short circuit, fires occur.

Designations of phase, neutral and ground wires

When installing electrical networks for domestic and industrial purposes, insulated cables are used. They consist of many conductive wires. Each of them is painted in a corresponding color. The designations LO, L, N in electrics allow you to reduce the time for installation and, if necessary, repair work.

The electrical designation L and N described below fully complies with the requirements of GOST R 50462 and is used in electrical installations in which the voltage reaches 1000 V. They have This group includes electrical equipment of all residential, administrative buildings, economic facilities. Which color designations phases L, zero, N and grounding must be observed when installing electrical networks? Let's figure it out.

Phase conductors

Online alternating current There are conductors that are energized. They are called phase wires. Translated from English, the term “phase” means “line”, “ active wire", or "live wire".

Human contact with a phase wire exposed from insulation can result in serious burns or even death. What does the electrical designation L and N mean? On electrical diagrams phase wires are marked with the Latin letter “L”, and in multi-core cables The phase wire insulation will be painted in one of the following colors:

• white;
• black;
• brown;
• red.

Recommendations! If for any reason an electrician doubts the veracity of the information displaying the color marking of the cable wires, a low-voltage tester must be used to determine which wire is live.

Neutral conductors

These electrical wires are divided into three categories:

• zero working conductors.
• neutral protective (ground) conductors.
• combining protective and working functions.

To determine which of the conductors is phase and which is neutral using an indicator screwdriver, you need to touch the uninsulated part of the wire with its tip. If the LED lights up, it means that a phase conductor has been touched. After touching the neutral wire with a screwdriver, there will be no glowing effect.

The importance of color marking of conductors and strict adherence to the rules of its use will significantly reduce the time of conducting installation work and troubleshooting electrical equipment, while ignoring these basic requirements results in a health risk.

Any electrical cable For ease of installation, it is manufactured with multi-colored insulation on the cores. When installing standard electrical wiring, three-core cables are usually used (phase, neutral, ground).

Phase ("L", "Line")

The main wire in the cable is always the phase. The word "phase" itself means "live wire", "active wire" and "line". Most often it comes in strictly defined colors. In the distribution panel, the phase wire, before going to the consumer, is connected through the device protective shutdown(RCD, fuse), phase switching occurs in it. Attention! The bare phase is no joke, so in order not to confuse the phase with anything else, remember: the phase contacts are always marked with the Latin symbol “L”, and the phase wire can be red, brown, white or black! If you are not sure about this or the wiring is arranged differently, then purchase a screwdriver with simple indicator phases. By touching the bare conductor with its tip, you can always find out whether it is a phase or not by the characteristic glow of the indicator. It’s better to immediately contact a qualified specialist.

Zero ("N", "Neutre", "Neutral", "Neutral" "Zero")

The second important wire is the neutral, popularly known as the “wire without current”, “passive wire” and “neutral”. It only happens blue. In apartment distribution panels it must be connected to the zero bus, it is marked with the symbol “N”. At the socket, the neutral wire is connected to the contacts, also marked with the sign “N”.

Ground ("G", "T", "Terre" "Ground", "gnd" and "Earth")

Ground wire insulation can only be yellow with green stripe. In the distribution panel it is connected to the grounding bus, to the door and body of the panel. In sockets, grounding is connected to contacts marked with the Latin symbol “G” or with a sign in the form of an inverted and briefly underlined letter “T”. Typically, grounding contacts are visible and can protrude from sockets, becoming accessible to children, which sometimes causes shock to many parents; however, these contacts are not dangerous, although sticking your fingers there is still not recommended.


Attention! When working with electrical networks under voltage there is always a high probability of injury to a person electric shock or fire. Even if an RCD is installed, it is strongly recommended to follow all safety precautions! It is known that the special design of such a switch checks the synchronism of the phase and zero operation, and if the RCD detects a phase current leak without returning some of its percent to zero, it will immediately break the contact, which will save a person’s life; however, if you touch not only the phase, but also zero, then the RCD will not save you. Touching both wires is deadly!!!

Wiring in buildings consists of insulated aluminum and copper wires. For convenient installation of electrical wiring, as well as for further maintenance of cables, manufacturers use different colors to mark current-carrying conductors in an electrical cable.

Mounting wire

What colors are found?

According to the Electrical Installation Rules (ELR), the insulating material of the wiring must be colored and easily recognizable by the technician. An electrical cable usually has a three-wire structure (phase, neutral, ground), each wire is painted a specific color. Now it’s hard to believe that not so long ago cable insulation had only two colors: black and white. But fortunately, with the introduction of new rules, color design has changed dramatically. Basically, the following colors are used for electrical wiring: white, black, red, light blue (blue), yellow-green, brown shades. Let's take a closer look at which conductor this or that color corresponds to.

A visual example of colors for electrical conductors.

Neutral

The neutral core is usually blue or blue color. In the distribution box, this wire is connected to the zero bus, which is marked with the Latin letter N. Everything is connected to this bus blue wires. It should be noted that the zero wire combines two functions: working and protective zero. The protective wire zero is also blue, and at the ends, i.e. at the junctions there are yellow-green stripes. Connects to a bus designated REN. It should be noted that generally accepted rules allow green stripes along the entire wire with blue endings.

Closed circuit diagram.

Ground wire

The grounding conductor is yellow or green color or marked with stripes of that color throughout the cable. Such a conductor is connected in the distribution panel to the grounding plate. In the junction box, the earth conductor is connected to the ground wires coming from outlets and electrical appliances, such as lamps, for example. The ground conductor is not connected to the residual current device.

What does a ground wire look like?

Wire phase

The vein responsible for the phase in electric wire, painted in different colors. It can be: black, brown, red, gray, purple, pink, white, orange, turquoise. Each manufacturer of electrical wires has the right to designate the phase conductor in one of these shades. Simply put, the main task of an electrician when installing the electrical wiring of a room is to first determine the neutral and ground wires, and the remaining wire will be the phase. To avoid electric shock, an electrician must check the wires using a special tester, most often in the form of a screwdriver.

What color can the wires in the cable be?

How to color code your wires yourself

There are cases when the wires have a non-standard color, different from those listed in the PUE. In such situations, you can independently color-code the cable cores. To do this, we use colored electrical tape, which we use to mark the ends of the wires in the distribution panel. There is also a special heat-shrinkable tube for such purposes, it is sometimes called cambric. After this, do not forget to write down your designations so that there is no confusion in the future.

Colored electrical tape to mark wires.
Heat-shrink tubing for insulating wires.

Video. What does it look like junction box in a residential area. How the color marking of wires has changed since the times of the USSR

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IN modern life Marking wires by color is not an advertising ploy by the manufacturer to stand out from others. This is a necessity and requirement, without which rapid and high-quality installation electrical wiring. How does this color help?

• quick identification of wire purpose (phase, neutral or ground)
• reducing the number of erroneous connections during the installation process
• no need to test the wire for phasing

Manufacturers choose conductor colors not according to their own wishes, but according to the rules. Moreover, not only color can be applied to the conductor, but also digital letter designation.

The color is applied along the entire length of the core insulation. But in some areas you can also use multi-colored cambrics for heat shrink. They are mainly widely used in cable terminations.

Coloring for 220V and 380V single-phase and three-phase voltage

IN three-phase network wires and buses were previously painted as follows:

Yellow color

Green color

Of red color

To make it easier to remember the order of colors, electricians used the abbreviation ZH-Z-K.

From 01/01/2011, new standards were introduced in accordance with GOST R 50462-2009 ():

Brown

Now it's time to switch to abbreviations - K-H-S! Subjectively speaking, this marking is inferior in clarity to the previous color scheme Zh-Z-K.

Imagine that in a switchboard or indoors bad light, dust on the wires? Which do you think your eye is better at distinguishing between yellow and green or brown and black? The rules in this case stipulate the need for letter designation and marking of the cores, in addition to color.

Letter designation of wires

What should be the letter designation of wires according to GOST is presented in the following tables:

It is best to apply these letters using special tag rings.

They are a PVC tube, pre-cut, with letters and numbers printed on it.

According to the new rules, marking phase conductors yellow or green is prohibited. Precisely because of their similarity with the yellow-green grounding conductor.

It is also worth noting that the brown color is precisely phase A or L1 (simply L in a single-phase 220V network), and black is phase B or L2. When you conduct wiring for yourself, you may unwittingly miss this moment. But if the electrical work is done at industrial facility, then here you will be required to strictly comply international standard and correct phasing.

White color is the cheapest option when making core insulation, as it does not require the use of dyes. Therefore, it is most often used by manufacturers of cheap cable brands. There are no special labeling guidelines for this color.

Coloring in a DC network

DC networks use 3 buses. The usual zero and phase are missing here. There is a positive conductor or bus (with a plus sign) and a negative conductor (with a minus sign). According to the old rules, the positive tire should be red, the negative tire should be blue. Zero operating bus - blue.

According to new standards from 01/01/2011:

Plus

Brown

Minus

Gray color

Middle conductor

Of blue color

Errors and color options for phase, neutral and ground wires

The issue of marking wires by color becomes acute when the wiring is installed by one electrician and then serviced by another. If you follow all the color rules, you will save a lot of time and money on troubleshooting.

Unfortunately, in old Soviet wiring, most of the conductors are single-colored and there is no way to do this without a probe or multimeter.

If color marking exists and is observed, then the neutral and protective wires should be:

Neutral wire N should be blue.
Zero protective PE – yellow-green.
The conductor combining the protective zero and the working zero PEN is yellow-green along the entire length of the wire, but at the end at the junction it is blue.

When coloring phase wires The manufacturer is given a choice of many color options. Here are the main ones:

Non-standard wire color options

Sometimes, due to incorrect labeling of colors by manufacturers, GOST standards have to be ignored. For example, you have 3 wires in a cable of different colors:

• blue
• brown
• black

In this case, you do the phase according to the rules, namely - brown. The neutral wire will be blue. But the black core will become grounding. In this version, the colors will at least resemble the Soviet standard.

Another of the “inconvenient” options for combining colors of cable cores:

• black
• blue
• red

To violate GOST as little as possible and be close to its requirements, make the phase black. Blue is zero, but red will be protective conductor P.E.

Just be sure to mark it at the end with yellow and green electrical tape.

What to do if the cable does not have a single color that resembles a phase wire? That is, the colors black, brown and gray are missing. Then choose for the phase the wire that corresponds as closely as possible to established by the rules brown color. For example, red.

At the ends of the wires, according to the phasing, you can put on multi-colored insulating thermal tubes or multi-colored electrical tape.
To avoid resorting to such methods, at the stage of purchasing and selecting a cable, pay attention to its color in advance.

What to do if the cable has already been laid without observing color markings?

Most often, you may encounter a situation where the wiring has already been laid, and the electrician who did it, as a rule, did not bother to familiarize himself with the rules of color marking and GOST. What to do in this case?

There is nothing left to do but pick up the instruments - a probe, an indicator, a dialer, and spend time looking for the necessary conductors.
After each definition of a particular conductor, use colored cambrics to designate them according to GOST and move on to the next one. It is enough to make this designation only at the end and beginning of the cable, and not along its entire length.

It is easy to distinguish phase conductors from neutral conductors. How to distinguish a zero worker from a protective one can be found in the article "".

Tips related to wire colors that should be followed during installation:

• try not to use cables different manufacturers. As a rule, their colors are not the same, which can lead to installation errors in the future.
• if you still have to work with cables of different manufacturers and colors, at the very beginning, ring all the cores and mark them in advance with multi-colored electrical tape so as not to confuse them in the future. Don't rely on your memory
• when you have to increase short cable, then use wires of the same colors as in the main section.
• try not to use cables that do not have yellow-green cores ( protective zero)
• If the cable does not have a yellow-green core, then use the closest related color as the ground.