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What color is the phase wire? What is color coding of buses and wires and why is it needed? Non-standard wire color options

There are, in fact, not many different types of conductors and their connections. In the electrical power industry, a distinction is made between supply and protective conductors. Some have heard words such as “neutral” and “phase” wire. However, this is where questions arise. How to determine zero and phase in a real network?

What kind of conductors are there in a socket?

You can understand the question “what is phase and zero” without delving into the jungle of clarifying the structure, advantages and negative aspects of three-phase or five-phase circuits. You can practically disassemble everything on your fingers by opening the most ordinary household outlet, which is installed in an apartment or a private house ten to fifteen years ago. As you can see, this outlet connects to two wires. How to determine zero and phase?

How do the wires in a socket work and why are they needed?

As you can see, there are certain differences between workers and zeros. What is the symbol for phase and zero? A bluish or blue color is the color of the phase wire, while zero is indicated by any other colors, with the exception, of course, of blue colors. It can be yellow, green, black and striped. There is no current flowing. If you take it and do not touch the worker, then nothing will happen - there is no potential difference on it (in essence, the network is not ideal, and there may still be a small voltage, but it will be measured in millivolts at best). But this will not work with a phase conductor. Touching it may result in an electric shock, even fatal. This wire is always energized; current flows to it from generators and transformers and stations. You must always remember that you should never touch the working conductor, since voltage of even a hundred volts can be fatal. And in the outlet it is two hundred and twenty.

How to determine zero and phase in this case? The socket, designed in accordance with European standards, contains three conductors at once. The first is phase, which is energized and painted in a variety of colors (with the exception of blue shades). The second is zero, which is absolutely safe to touch and is colored. But the third wire is called neutral protective. It is usually colored yellow or green. It is located in the sockets on the left, in the switches - at the bottom. The phase wire is located on the right and top, respectively. Given these colors and features, it is easy to determine where the phase is, where the zero is, and where the protective neutral wire is. But what is it for?

Why is a protective conductor needed in European sockets?

If the phase wire is intended to supply current to the socket, and the neutral wire is intended to lead to the source, then why do European standards regulate another wire? If the equipment that is connected is working properly, and all wiring is in working condition, then the protective zero will not take part, it is inactive. But if suddenly an overvoltage occurs somewhere, or a short circuit occurs on some parts of the devices, then the current enters places that are usually without its influence, that is, not connected to either a phase or a zero. A person will simply be able to feel the electric shock on himself. In the worst situation, you can even die from this, as the heart muscle can stop. This is where the protective neutral wire is needed. It "takes" the short circuit current and directs it to the ground or to the source. Such subtleties depend on the wiring design and the characteristics of the room. Therefore, you can safely touch the equipment - there will be no electric shock. The thing is that current always flows along the path of least resistance. In the human body, the value of this parameter is more than one kiloohm. The resistance of the protective conductor does not exceed a few tenths of one Ohm.

Determining the purpose of conductors

How to determine zero and phase? Any person has encountered these concepts in one way or another. Especially when you need to fix an outlet or do some wiring. Therefore, it is necessary to understand exactly where each conductor is. But how to determine zero and phase? It must be remembered that all manipulations of this kind with electricity are dangerous. Therefore, if you are unsure of your actions, it is better to contact a specialist. If you are already approaching the outlet and the wires in it, then you must first completely turn off the power to the entire apartment. At a minimum, this can save health and life. As mentioned earlier, usually the designation of phase and zero is done using coloring. With proper labeling, distinguishing them will not be difficult. Black (or brown) is the color of the phase wire; neutral usually has a bluish or bluish tint. If a European standard socket is installed, then the third (protective zero) is green or yellow. What to do if the wiring is one color? As a rule, in this case, at the ends of the wires there are usually special insulating tubes that have the necessary color markings. They are called "cambrics".

Identifying conductors using a special screwdriver

How to determine zero and phase? To do this, it is most convenient to buy a special indicator screwdriver. The handle of such a device is made of translucent or transparent plastic. There is a built-in diode - a luminous light bulb - inside. Top part This screwdriver has a metal one. How to determine zero and phase using this method?

The procedure for performing measurements using an indicator screwdriver:

• de-energize the apartment;
• lightly strip the ends of the wires;
• we move them apart so as not to accidentally cause a short circuit by contacting the phase and zero;
• turn on the switch and supply current to the apartment;
• We take the screwdriver by the handle, which has a dielectric coating;
• place your finger (thumb or forefinger) on the contact, which is located on the back of the socket;
• touch the working end of the indicator to one exposed conductor;
• carefully observe the reaction of the screwdriver;
• if the diode lights up, then we can confidently state that;
• By method of elimination we understand that the remaining conductor is zero.

The indicator screwdriver reacts to the presence of voltage. Naturally, it is not in the neutral wire. However, there is significant drawback such a method. By using indicator screwdriver It is impossible to understand how to determine: phase, zero, ground - where is what in the case of a European socket.

Method for determining phase and zero using a voltmeter

If the wires are not painted in the appropriate colors, and you don’t have an indicator screwdriver at hand, then you can go another way. We need a voltmeter (multimeter, tester). It is necessary to set it to the required range - over two hundred volts alternating current. How to determine the phase with a tester? We take one conductor that extends from the device (labeled V). We attach it to a previously de-energized conductor (any). Then we apply current (turn on the switch). And we simply record what the device display shows. After all of the above, turn off the power again and transfer the tester clamp to another conductor. If there is nothing on the display, this means that in front of us there is either a zero or a grounding protective neutral wire. However, you can use another method that answers the question: “How to determine zero and phase, as well as grounding.” To do this, we turn off the power to the apartment again and fix the V clamp on one of the wires. We also throw the second one onto any of the three conductors. The voltage turns on. If the arrow does not move, then you have chosen zero and protective. Accordingly, the voltage must be turned off again and the position of terminal V must be changed (place it on another previously unused conductor). We turn on the current again and take the appropriate measurements. Then we perform the same operation, but change the conductor again. Now you need to compare the results. If the first digit turned out to be larger, it means that we measured the voltage between the phase conductor (on which terminal V hung) and the zero one. Accordingly, the second wire will be a protective grounding wire. This method is based on measuring the potential difference.

Exotic ways to determine phase and zero in wiring

There are also " traditional methods", which do not imply the presence of any special devices. They can be used only in the most extreme cases, since they are associated with an increased danger to health and life. For example, the potato method. To do this, put a freshly cut piece of potato on the previously de-energized conductors. It is necessary to prevent the wires from touching each other so that there is no short circuit between them. Then literally apply voltage for a couple of seconds and look at the potatoes. If one section near the wire turns blue, then a phase is connected to it.

In electrical installations and household electrical networks, conductors with various purposes. The main ones used for transmitting electrical energy are phase voltage conductors, zero operating and zero protective.

They all must be identified. Otherwise, even if there are schematic, 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 conductor identification is electrical safety. Touching any live parts, even those not at a life-threatening potential, is prohibited without checking that there is no 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 organizing the safe operation of electrical installations.

Identification of conductors of power electrical circuits is carried out using 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 markings to conductors used in power electrical circuits are described in detail in GOST R 50462-2009. Despite the fact that it has the status of a 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 manufactured according to European standards is supplied to Russia, and therefore, for its correct operation, our own rules must be brought into line with the IEC.

So, let’s now 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 ones.

In single-phase circuits, all phase conductors according to GOST must be brown. However, this does not mean at all that when installing a single-phase distribution panel you need to use exactly these wires. Their color may not necessarily be brown, but any color other than 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 panel is connected to.

However, if this single-phase circuit branches off from a three-phase circuit as part of a device or panel, 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.

The cores of cables intended for installation of single-phase networks are colored brown, blue and yellow-green.

Phase wires in three-phase networks were previously marked with letter designations: A, B and C. In addition, the busbars 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 colors for marking, since they can be confused with yellow-green, which has a different purpose, which will be discussed below.

It was not customary to mark the wires at all. A good example of this is the access distribution boards. All the wires in them: both phase and neutral are the same. An attempt to determine their purpose is fraught with some difficulties: after all, you can even conclude that the conductor is connected to a phase of the supply network with confidence 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 requires the following marking for phase conductors.

It is allowed to mark wires in any of two ways or both at once. In the first case, tags with letter designations are attached to the ends of the wires, in the second, the corresponding coloring of the current-carrying parts is used. Strictly speaking, when installing switchboards, use wires that have brown, black and gray colors not at all necessary. Linking to color is more relevant to cable lines, since their veins are colored brown, black, gray, blue and yellow-green. When connecting cables to terminal blocks, consumers or electrical equipment terminals, it is necessary to comply with GOST requirements.

For the assembly of panel board products, installation of phase circuits may be performed with single-color wires, while observing the following 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 brown, black, gray, as well as blue and yellow-green, denoting them with letter markings. At the same time, the cost of assembling panel board products and complete switchgears is slightly reduced. But in return, a disadvantage arises: 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 PUE, which specifies the requirements for the relative position of the tires. But there are electrical installations in which the phase rotation cannot comply with the PUE. Therefore, when marking tires, you need to stick labels on them as often as possible. GOST requires marking to be carried out at least twice within a panel or shield: at the bus entrance to the panel and at the exit, or at its beginning and end.

Marking of conductors “ground” and zero

Here, the labeling requirements are much stricter, since this is directly related to electrical safety.

The protective zero (or ground), as well as live parts intended for the potential equalization system, are marked with alternating yellow and green stripes. For buses, this is a uniform alternation of stripes of yellow and green colors, while the wires and cable cores are painted accordingly at the factory.

It is prohibited to use yellow-green and blue colors to mark other circuits, as well as to mark 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.

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

It is a little more difficult to mark the combined zero, which is designated PEN. Since it combines the functions of the ground conductor and the working zero, this is taken into account when marking. It is permissible to use two similar methods: either take a blue wire and apply yellow-green markings on its ends, or apply blue markings on the ends of a yellow-green wire. This can be done either using insulating tape or heat-shrinkable tubing.

For identification purposes, the tires do not need to be painted along their entire length, since this method is difficult for these chains. On the busbars intended for connecting the ground and neutral conductors, there are many holes for their connection, which makes continuous painting difficult, and at times impossible. It is allowed to apply colored stripes of blue or yellow-green along the edges of the tire.

To make the work of electricians easier, the production of cable insulation is subject to certain color marking standards. When connecting a multi-core cable, you can identify the core by the color of the polymer sheath and understand which contact it should be connected to.

Different colors of electrical wires, established by GOST provisions, help speed up the installation process and ensure electrical safety. Agree, understanding color coding is useful to every home craftsman.

We suggest you understand the symbols of electrical wiring, learn GOST standards and learn to read the letter codes of wires on diagrams. In addition, we will tell you how to check the compliance of the connected core with its intended purpose using an indicator screwdriver or a multimeter.

The main document that you should rely on when producing or is GOST 31947-2012. Before its appearance, there was no uniformity and order in the field of color designation of electrical wiring.

Until now, in old houses you can find wires in the same sheath, the color of which cannot determine what is connected - “phase”, “zero” or “ground”.

Now it has become much easier to identify veins. Even without using a tester, you can determine which contact a particular core should be connected to - by the color of the polymer insulation

The above-mentioned GOST document states that the insulation of cable products should differ in color. A certain shade should cover the wire with a continuous layer - from beginning to end. It is impossible for one wire at the beginning of the bay to be blue and the end to be white; Intermittent painting is also prohibited.

Electrical cables produced during the USSR period had predominantly black or white insulation, which created difficulties and inconveniences during electrical work, because It was not always possible to quickly identify the purpose of a particular wire. Nowadays there are cables of various colors on the shelves. This diversity has a very specific purpose. Color marking of wires of each type (zero, minus, plus, ground and various phases) is primarily intended to make electrical installation work safer, and finding and connecting contacts easier and faster.

In order to avoid discrepancies in the color scheme, depending on which manufacturer manufactured this product, it is strictly standardized in the PUE (electrical installation rules) and state standards. Until 2009, GOST R 50462-92 was used; in GOST R 50462-2009, which replaced it, changes were made regarding the colors of wires in three-phase networks, the color of plus, minus and zero in DC networks; brown was recommended as the main shade for the phase in a single-phase network, the use of a combination of yellow and green for grounding is approved.
There are different types of cables:

• Black
• Brown
• Red
• Orange
• Yellow
• Green
• Blue
• Purple
• Gray
• White
• Pink
• Turquoise

The cable is marked with the required color at the ends (in other words, in the connection area), as well as along its entire length in the form of solid colored insulation or individual marks.

Coloring of different types of cables

Three-phase networks

In a three-phase network of transformer substations with alternating current, according to GOST 1992, phase A has a yellow wire, B has a green wire, C has a red wire. According to the new GOST, it is preferable to use brown for phase A, black for phase B and gray for phase C. In ordinary household cables, white is used for phase A, black for phase B, and red for C.
The ground wire is usually colored in the form of yellow-green stripes in the longitudinal or transverse direction. Moreover, each color cannot occupy less than 30% and more than 70% of the surface. Less commonly, the ground cable marking may be only yellow or only green. If such a cable is laid in an open way, then it is permissible to use black color, as it improves corrosion protection. Also, the color black was used to indicate the ground wire everywhere before changes were made to regulatory documentation in 2009.
Zero has wire insulation blue or blue color.

Single-phase networks

In this type of AC network, the phase insulation is most often brown, gray or black, but red, purple, pink, white and turquoise shades. At the same time, in a single-phase network powered by a single-phase energy source, wires with brown insulation are usually used. If a single-phase conductor is made as a branch of a three-phase electrical circuit, then it is marked with the same color as the phase of the three-phase circuit.
The ground wires, similar to the previous case, are marked with a combination of yellow and green.
PEN conductors, in which the protective zero and working zero are connected along the entire length, are painted blue and have yellow-green markings at the ends. At the same time, GOST allows another option - yellow-green lines along the entire length of the wire and blue marks at the ends.

DC networks

If a system with a DC network was put into operation before 2009, then the zero should be light blue, the plus should be red, and the negative pole should be dark blue. According to the new GOST, brown should be used for plus, gray for minus, and blue for zero.

Labeling rules

Marking is performed on the ends of the wires, i.e. in places where they are connected to each other or to various equipment.
It is permissible to combine colors permitted for marking, but avoid confusion whenever possible. So, yellow and green can only be used in combination with each other and only for grounding, and not, for example, plus/minus.
If the wires in the system are initially marked incorrectly or not marked at all, this can be corrected:

• By applying letter, symbol or color markings with indelible markers (convenient if the wire is white or at least light)
• Sticker of polyurethane tags with inscriptions
• Using heat shrink tubing or insulating tape desired color

Naturally, you need to first determine which wire is positive, which is negative, etc. the purpose of each wire (in a household electrical network this can be done using an indicator screwdriver or a multimeter).
It is not always possible to create a color circuit diagram in paper version. Then, in black and white copies, letter designations are used to uniquely identify the color of each type of wire. Their complete list is given in GOST R 50462-2009. To mark cables that include several wires of different types, different colors are separated by a plus sign in letter designations.

Conclusion

Color marking of wires depending on the purpose of each of them makes electrical installation work more convenient and reduces the likelihood of errors and emergency situations. Therefore, it is necessary to comply with it even for the individual power supply system of an apartment or house, not to mention larger industrial, commercial, public and other facilities.

Today it is difficult to imagine electrical wiring without the use of colored insulation. And these are not marketing “tricks” of manufacturers seeking to present their goods in colors, and unfashionable innovations that consumers strive for. In fact, this is a simple and practical necessity, which is determined by strict state standards for compliance with correct labeling. What is it for.

Wire colors in electrical connections

Color marking

All the variety of colors and certain colors selected from this palette are reduced to one (single) standard (PUE). Thus, wire cores are identified by color or letter and number designations. Adoption uniform standard color identification of electrical wires greatly facilitated the work associated with their switching. Each vein has specific purpose and is indicated by the corresponding tone (blue, yellow, green, gray, etc.).

Wires are marked by color along their entire length. Additionally, identification is carried out at connection points and at the ends of the cores. To do this, use colored electrical tape or heat-shrinkable tubes (cambrics) of appropriate colors.

Let's look at how electrical wiring is done and wire color coding for three-phase, single-phase and DC networks.

Color marking of wires and buses of three-phase alternating current

Painting of busbars and high-voltage transformer bushings in three-phase networks is done as follows:

• tires with phase “A” are painted yellow;
• buses with phase “B” - green;
• buses with phase “C” - red.

Marking of wires by color. Electrical wire colors (DC buses)

In the national economy, direct current circuits are often used. They find their application in certain areas:

In DC networks there is no phase and neutral contact. For such networks, only two contacts of different polarities are used - plus and minus. To distinguish them, two colors are respectively used. A positive charge turns red and a negative charge turns blue. Blue color indicates the middle contact, which is marked with the letter “M”.

“Old-timers” of electrical installation are probably familiar with the old methods of wiring and color marking of electrical wires. The main colors of the electric cable were white and black. But that time is a thing of the past. Each color now, and there are clearly more than two, has its own purpose and dominant profile.

Contact colors in electrics indicate the purpose and belonging of conductors to a specific group, which facilitates their switching. The likelihood of an error during the installation process, which could lead to a short circuit during a test connection or electric shock during repairs, is significantly reduced.

Marking of wires by color. Color palette of protective zero and working contacts

The zero working contact is indicated by a blue tone and the letter N. The PE marking indicates the zero protective contact, which is painted in yellow-green stripes. A combination of such tones is used when marking pinch conductors.

A blue conductor along its entire length with yellow-green stripes at the connection points indicates a combined zero working and zero protective connection (PEN). However, GOST also allows for the opposite of this color:

1. Working zero contact is designated by the letter N and is blue in color.
2. Protective zero(PE) with a yellow-green color.
3. Combined(PEN) are identified by their yellow-green color and blue markings at the ends.

Single-phase electrical circuit. Coloring of phase wires

According to PUE standards, phase contacts are usually indicated in black, red, purple, white, orange or turquoise.

Single-phase electrical circuits are created by branching off a three-phase electrical network. In this case, the color of the phase contact of a single-phase circuit must match the color of the phase wire of a three-phase connection. In this case, the color marking of the phase contacts should not match the N - PE - PEN colors. On unmarked cables, colored marks are placed at the connection point. To designate them, use colored electrical tape or heat-shrinkable tube (cambric).

What color is the ground wire? Marking of wires by color (phase - zero - ground)

When installing lighting networks and power supply to sockets, use a cable with three wires (three-core cable). The use of a standard color system (color of phase-neutral-ground wires) significantly reduces repair time. Multi-core wiring in standard multi-colored insulation greatly simplifies the laying of electrical circuits and installation work on wiring AC networks with its grounding. This is especially true when wiring and repairing the electrical system, which is done by different craftsmen, but under the general guidance of GOST. Otherwise, each master would have to once again double-check the work of his predecessor.

“Earth” is usually indicated by the color yellow-green and marked PE. Sometimes there is a green-yellow color and the marking “P E N”. In this case, there is a blue braid at the ends of the electrical wire at the attachment points and the grounding is combined with the neutral.

The distribution panel is connected to the grounding bus and to the metal door of the panel. The junction box is usually connected to the grounded wires of fixtures or the grounding pins of outlets.

Marking of wires by color. Designation of zero and neutral

“Zero” is indicated in blue. In the distribution panel it is connected to the zero bus and is designated by the letter N. All blue wires are also connected to the bus. It is connected to the output using a meter or directly, without installing an automatic device.

The distribution box wires (with the exception of the wire from the switch) are indicated by a blue neutral palette. When connected, they do not take part in the switching process. The blue “zero” wires are connected to the sockets and contact N, which is marked on the back of the socket.

Marking of wires by color. Phase color designation

The phase wire is usually indicated in red or black. Although its colors may not be so clear. It can also be brown, but never blue, green or yellow. In automatic switchboards, the “phase” coming from the consumer’s load is connected to the lower contact of the meter. Switching of the phase wire is carried out in switches. In this case, the contact closes during shutdown and voltage is supplied to consumers. The black wire of the phase socket is connected to the contact, which is designated by the letter L.

Alphanumeric designation of wires by color

Knowledge of basic color markings of wires and their purpose will help any amateur electrician in installing home electrical wiring (with grounding). If you wish, you can easily make it according to the required standards in compliance with all technical standards.

Those who have dealt with electrical wires at least once in their lives could not help but notice that the cables always have different insulation colors. It was not invented for beauty and bright colors. Thanks to color scheme When wearing wires, it is easier to recognize phases, grounding and neutral wires. All of them have their own coloring, which makes working with electrical wiring many times more convenient and safe. The most important thing for the master is to know which wire should be marked with which color.

Wire color coding

When working with electrical wiring, the greatest danger is represented by the wires to which the phase is connected. Contact with the phase can be fatal, so the brightest warning colors, for example red, were selected for these electrical wires.

In addition, if the wires are marked with different colors, then when repairing a particular part, you can quickly determine which of the wire bundles need to be checked first, and which of them are the most dangerous.

Most often, the following colors are used for phase wires:

• Red;
• Black;
• Brown;
• Orange;
• Lilac,
• Pink;
• Violet;
• White;
• Gray.

It is these colors that phase wires can be painted. You can deal with them easier if you exclude the neutral wire and ground. For convenience, in the diagram the image of a phase wire is usually denoted by the Latin letter L. If there is not one phase, but several, a numerical designation should be added to the letter, which looks like this: L1, L2 and L3, for three-phase in 380 V networks. In some designs, the first phase (mass) may be designated by the letter A, the second by B, and the third by C.

What color is the ground wire?

According to modern standards, the grounding conductor should be yellow-green in color. In appearance it looks like yellow insulation, on which there are two longitudinal bright green stripes. But sometimes there is also a color of transverse green-yellow stripes.

Sometimes, the cable may only have bright green or yellow conductors. In this case, “earth” will be indicated by this color. It will also be displayed in the corresponding colors on the diagrams. Most often, engineers draw bright green wires, but sometimes you can see yellow conductors. On diagrams or devices, “ground” is designated by the Latin (in English) letters PE. Accordingly, the contacts where the “ground” wire needs to be connected are also marked.

Sometimes experts call the grounding wire “neutral and protective,” but this should not be confused. If you see such a designation, then know that this is an earth wire, and it is called protective because it reduces the risk of electric shock.

The zero or neutral wire is marked in the following color:

• Blue;
• Blue;
• Blue with white stripe.

No colors are used in electrical engineering to mark the neutral wire. This is how you will find it in any, be it three-core, five-wire, or maybe with even more conductors. Blue and its shades are usually used to draw “zero” in various diagrams. Professionals call it a working zero because (which cannot be said about grounding) it is involved in electrical wiring with power. Some, when reading the diagram, call it a minus, while everyone considers the phase “plus”.

How to check wire connections by color

Electrical wire colors are designed to make it easier to identify wires. However, relying only on the color is dangerous, because some newbie, or an irresponsible employee from the housing and communal services complex, could connect them incorrectly. In this regard, before starting work, it is necessary to ensure that they are correctly marked or connected.

In order to check the wires for polarity, take an indicator screwdriver or a multimeter. It is worth noting that it is much easier to work with a screwdriver: when you touch the phase, the LED built into the housing lights up.

If the cable is two-wire, then there are practically no problems - you have eliminated the phase, which means the second conductor that remains is zero. However, three-core wires are also common. Here you will need a tester or multimeter to determine. With their help, it is also not difficult to determine which wires are phase (positive) and which are neutral.

This is done as follows:

• The switch is set on the device in such a way as to select a jackal of more than 220 V.
• Then you need to take two probes in your hands, and holding them by the plastic handles, very carefully touch the rod of one of the probes to the found phase wire, and lean the second one against the supposed zero.
• After this, the screen should display 220 V, or the voltage that actually exists in the network. Today it may be lower.

If the display shows a value of 220 V or something in this range, then the other wire is zero, and the remaining one is presumably ground. If the value that appears on the display is less, you should continue checking. We again touch the phase with one probe, and the supposed ground with the other. If the instrument readings are lower than in the case of the first measurement, then in front of you is “ground”. According to standards, it should be green or yellow. If suddenly the readings turn out to be higher, this means that you have made a mistake somewhere, and you have a “zero” wire in front of you. The way out of this situation is to either look for exactly where the wires were connected incorrectly, or leave everything as is, remembering that the wires are mixed up.

Wire designations in electrical diagrams: connection features

When starting any electrical installation work on lines where a network has already been laid, you need to make sure that the wires are connected correctly. This is done using special testing devices.

It must be remembered that when checking the phase-zero connection, the readings of the indicator multimeter will always be higher than in the case of continuity of the phase-ground pair.

According to the standards, wires in electrical circuits are color coded. This fact allows the electrician to find zero, grounding and phase in a short period of time. If these wires are connected incorrectly to each other, a short circuit will occur. Sometimes such an oversight results in a person receiving an electric shock. Therefore, you cannot neglect the rules (PUE) of connection, and you need to know that the special color marking of wires is intended to ensure safety when working with electrical wiring. In addition, this systematization significantly reduces the electrician’s work time, since he is able to quickly find the contacts he needs.

Features of working with electrical wires different color:

• If you need to install a new one or replace an old outlet, then it is not necessary to determine the phase. It doesn't matter to the plug which side you connect it to.
• In the case when you connect a switch from a chandelier, you need to know that it needs to be supplied with a specific phase, and only zero to the light bulbs.
• If the color of the contacts and phase and zero are exactly the same, then the value of the conductors is determined using an indicator screwdriver, where the handle is made of transparent plastic with a diode inside.
• Before identifying a conductor, the electrical circuit in a house or other room must be de-energized, and the wires at the ends must be cleaned and spread apart. If this is not done, they may accidentally come into contact and result in a short circuit.

The use of color marking in electrical engineering has made people's lives much easier. In addition, thanks to color coding, safety when working with live wires has risen to a high level.

Designations and colors of wires in electrical engineering (video)

Those who work with electrical wiring, whether they are skilled craftsmen or novice electricians, should be careful during the installation of electrical wiring and know which wire is designated as. When laying wiring and connecting contacts, always connect the conductors according to the color coding according to the new rules, and for the sake of your safety and respect for those who will work with them in the future, do not confuse them. Remember that your mistake can lead to negative and disastrous consequences.

When working with electricity, a large number of cables of different sizes and colors are used. To always pick the right product There is color marking of wires. Thus, individual cables are always marked with the same color for convenient use. For example, the color of the ground wire is always green-yellow insulation, and the color of the phase is green. This allows you to determine the purpose of the wire without testing and, if necessary, do it with another branch.

If there are several phases and neutral wires in the network, they are marked with colors according to the set of rules for working with electricity. Usually these are colors close to the main color, but depending on the network they may differ.

electrical safety

Alternating electric current with a voltage of 220 V or 380 V is dangerous for humans. careless touching exposed wires or metal parts of electrical equipment that may be live, causing severe burns or fatal injury!

For this purpose, the PUE gives an answer not only to the questions: what color is the ground wire, or what is PEN, but what is it for.

In order to maximally protect a person from possible exposure to electric current, electrical safety systems have been adopted, characterized by one or more factors, such as:
1. grounding;
2. protective grounding;
3. separation of networks by a transformer.

To provide safe work in existing electrical installations up to 1 kV, five grounding systems are used: TN-C, TN-S, TN-C-S, TT, IT s different ways grounding, grounding and separation of networks.

The PUE defines each of the systems as:
• TN-C, where the working zero N and the grounding PE conductors are combined in one PEN wire. Characterized by: the use of a cable with four cores in a three-phase network and a two-core cable in a single-phase network. This is the oldest device in electrical networks and is still found everywhere for reasons of economy, for example, in street lighting.
• TN-S, where the working N conductor and the grounding PE are separated from the supply transformer to the end consumer. Such networks are made of five-core cables for a three-phase network and three-core wires for a single-phase network.
• TN-C-S, where there is one combined PEN conductor of a four-core cable, from the supply transformer to the group panel at the entrance to the building, which is further divided into N and PE, respectively into five and three-wire wiring. This is the most common system for constructing power supply networks for buildings and structures.
• TT, where there is only one working N conductor, and only the electrical equipment body is grounded. In such a system, four and two-wire wiring are used, respectively. This is how overhead power lines are mainly constructed.
• IT, where the electrical installation is separated from the power supply network by a transformer and completely isolated from the ground. This is the most secure system for humans, used for consumers only for special purposes.

Thus, the color of the wires phase and zero, L and N in electrics will help to clearly determine the security system used in a given electrical network.

Specifics of various types of cable products

Before talking about marking, it is worth determining what the difference is between cable, wire and cord. Various types of cables can be used not only on the surface, but also underground and in water. This is possible because one or more insulated cores are protected by a special sheath, which can be made of various materials that can withstand aggressive environmental conditions.

Concerning electrical wires, then they also contain wires or cores twisted or insulated from each other. They are covered with a protective non-metallic sheath or winding, which does not imply their laying in the ground.

A cord is a wire containing flexible and insulated conductors. Using this type of cable product, various household devices and devices that are mobile or often move from place to place are connected to the network.

The classification of cable products depending on their purpose is as follows:
1. Power products. These include SIP and VVG wires. The latter variety is suitable for installing electrical wiring and lighting indoors, connecting electrical installations. Self-supporting insulated wire(SIP) used in construction air lines power transmission and creation of branches to residential buildings and buildings. The number of conductive cores in products marked VVG varies from 1 to 6. For the SIP variety, this figure ranges from 1 to 4.
2. The purpose of RF cables is to transmit a signal from one device to another.
3. Control products are needed to power devices and are indispensable in systems remote control. GOST allows the number of conductive cores in them from 4 to 37 pcs.
4. In order to coordinate the operation of instruments and devices at a distance, control wires are used along with the control type. Current-carrying cores in such products can be from 3 to 108 pcs.
5. A separate type of communication cable will be required in order for subscribers to be able to exchange information at a distance. Within this group there is a division into high- and low-frequency types of products.

Why is labeling necessary?

Specific colors in electrics were not chosen by chance. Colored wiring is required for safe conduction electro installation work to avoid short circuit and damage electric shock. Previously, the color of conductors was black or white, which resulted in great inconvenience for electricians.

When disconnecting, it was necessary to supply power to the conductors, after which zero and phase were determined using a tester. Using coloring took all that pain away because everything became very clear.

Color coding is almost always applied along the entire length of the conductor. It helps to establish the assignment of each conductor to a specific group in order to facilitate their switching. There are three types of wires in electrics: phase, neutral and ground.

To ensure clarity, simplicity and ease of recognition of individual parts of the electrical network, in accordance with clause 1.1.30 of the PUE, all electrical installations must have an alphanumeric and color designation. Moreover, the presence of one of these designations does not eliminate the need for the other.

Marking by color

Marking wires by color is the most visual and allows you to quickly determine the purpose of any wire. This marking can be done by selecting wires with the appropriate core insulation color, by applying paint to the busbars, or by painting or applying special colored tape at the core junctions.

Moreover, the paint on the tires may not be applied along the entire length, but only at the connection points or at the ends of the tires.

So:
• If we talk about the color designation of wires and cables, then we should start with the phase conductors. According to clause 1.1.30 of the PUE in a three-phase network, phase conductors must be marked in yellow, green and red. This is how phases A, B and C are designated respectively.
• The instructions for a single-phase electrical network suggest the designation of the phase wire in accordance with the color of which it is a continuation. That is, if a phase conductor is connected to phase “B” of a three-phase network, then it should be green.

Note! In a single-phase network in an apartment or house, you often do not know which phase your phase wire is connected to. In order to comply with GOST, you do not have to find out this at all. It is enough to designate the phase conductor with any of the proposed colors. After all, for a single-phase lighting network, it does not matter at all which phase your conductor is connected to. The only exception is the lighting network, which uses two different phase conductors.

• As for the neutral conductors, they should be blue in color. Moreover, the color of the neutral core does not depend on the three-phase, two-phase or single-phase network in front of you. It is always indicated in blue.
• Wire markings with a yellow-green stripe indicate a protective conductor. It is connected to the housing of electrical appliances and provides safety from electric shock if the insulation of electrical equipment is damaged.
• If the neutral and protective conductors are combined, then according to clause 1.1.29 of the PUE, such a wire core should have a blue color with yellow-green stripes at its ends. To make such markings with your own hands, you just need to take a blue wire and mark it with paint on its end seals or use colored electrical tape for this.
• As for DC networks, the positive core of a wire or bus should be indicated in red, and the negative core in blue. In this case, the designation of the neutral and protective conductors corresponds to the markings in alternating current networks.

Letter marking of wires

But color marking of wires is not always convenient. In shields and on diagrams it is much more convenient letter designation. It must be used in conjunction with the color designation.

So:
1. The letter marking of phase wires in a three-phase network corresponds to their colloquial designation - phase “A”, “B” and “C”. For a single-phase network it should be the same, but this is not always convenient. Moreover, it is not always possible to reliably determine which phase exactly. Therefore, the designation “L” is often used.

Clause 1.1.31 of the PUE standardizes not only the letter and color designation of conductors, but also their location. So for a three-phase network with vertical busbars, phase “A” should be the topmost, and phase “C” the bottom. And with a horizontal arrangement of conductors, the phase “C” closest to you should be, and the most distant phase “A”.

2. If the wires are marked in the panel, then the symbol “N” indicates the neutral wire.
3. The letter designation “PE” is used to designate the protective conductor. In addition, the grounding sign is often used, but the fact is that it cannot always accurately indicate the network diagram.
4. The fact is that you may come across the designation “PEN”. It denotes the combination of the neutral and protective conductors. This is possible in the TN-C-S systems which we discussed in one of our previous articles.
5. But the marking of DC electrical wires is carried out with the symbolisms “+” and “¬―”. Which respectively means positive and negative wire. For direct current there is another difference. The zero core is designated by the symbol “M”, which is sometimes misleading.

What do wire colors mean in electrical engineering?

Colored conductor insulation today - essential attribute for a successful and correct installation electrical wiring. This solution is by no means a way to make wires beautiful and attractive to the consumer; it is a convenient color marking, standardized and regulated throughout the civilized world, which is, without exaggeration, a necessity.

Color-coded wires provide precise identification of each conductor. The color of the core insulation determines its purpose in a group of several conductors and facilitates the switching and installation process.

This solution eliminates possible errors that could lead to fatal electric shock or short circuit. Electrical repairs and maintenance are also safer when wires are accurately marked.

The standard set out in the PUE strictly defines the colors of the markings, and thanks to this standard it becomes possible to easily identify each conductor, each cable core in a group by color or alphanumeric code.

As a rule, the entire conductor has a certain color, but it is also permissible to mark only the ends of individual cores at switching points where it is possible to use colored electrical tape or colored cambrics. Next, we will look in more detail at how exactly such marking is carried out for single-phase, three-phase and direct current networks.

Standard color marking of buses and wires for three-phase alternating current networks

In three-phase alternating current networks, inputs high voltage transformers both at stations and substations, as well as buses, are painted in the following colors, according to the phases:
• Phase “A” is colored yellow;
• Phase “B” is colored green;
• Phase “C” is colored red.

Standard color coding for DC wires and buses

DC circuits are characterized by only two buses: positive and negative. Here the positive wire (positive charge bus) is marked in red, and the negative wire (negative charge bus) is marked in blue, because the neutral and phase wires are fundamentally absent here. The middle wire (M) is marked blue.

In the case where a dc network containing two conductors is created by branching from a three-wire dc circuit, the conductors are marked in the same way as the corresponding conductors of the original three-wire circuit.

AC electrical networks are now always laid stranded wire insulated with cores of different colors, this greatly simplifies the installation process. If one installer does it, and in the future other people will carry out maintenance and repair of the network, they will no longer be forced to constantly identify “phase” and “zero”; they will simply be guided by color.

The function of marking is to create the ability to quickly and easily visually determine the purpose of each specific conductor for any section of it; this is one of the main requirements of the PUE. What colors, according to GOST, should conductors have? electrical installations alternating current for voltages up to 1000 volts and with a solidly grounded neutral, which includes almost all residential buildings and administrative buildings?

The neutral working conductor (N) is marked in blue. For the neutral protective conductor (PE) - yellow-green markings in the form of stripes along or across the core. This marking in the named color combination is relevant only for grounding conductors (for neutral protective conductors).

When the neutral working conductor is made combined with the neutral protective conductor (PEN), then along the entire length of the wire the marking is blue, and at the connection points (at the ends of the conductor) there are yellow-green stripes, or vice versa: a yellow-green conductor with blue ends.

So, neutral wires are marked with the following colors:
1. Neutral working wire (N) – blue marking;
2. Neutral protective conductor (PE) – yellow-green marking;
3. Neutral combined wire (PEN) - yellow-green marking with blue marks at the ends or vice versa.

Phase wires, in accordance with the PUE standard, can be marked in one of these colors: red, black, purple, brown, gray, pink, orange, turquoise, or white. If a single-phase electrical circuit is obtained by branching from a three-phase network, then the phase wire of the resulting single-phase circuit must necessarily match the color of the original wire of the three-phase network from which the branch was made.

The wires are marked so that the colors of the phase wires in no way match the color of the neutral conductor. And if an unmarked cable is used, then color marks are made at the ends of the cores, at the joints, using heat-shrink tubes or colored electrical tape. But to prevent unnecessary work on making tags, it is enough to initially choose the right insulation color, choosing a cable of sufficient length for your needs.

Sometimes an electrician at work has to deal with not very pleasant situations when the wiring has already been done, and neither the connections in the panel nor the wires are marked, in this case the person has to waste time and, using a probe, identify “phase”, “zero”, and "grounding".

However, you should always remember that even if it is not possible to purchase a wire of the desired color, you can, of course, use a wire of any color, but then you must definitely mark the ends of the wires with at least colored heat shrink or colored electrical tape. And always remember to be careful when installing electrical wiring and always follow safety precautions.

Marking of aluminum cables

APPV 2x6-380 - aluminum wire, PVC coated, flat, has a separator (about the definition a little below), 2 cores with a cross-section of 6 mm. It should be noted that the letter designation is used mainly for high-voltage options.

Color coding helps determine the purpose of the cable. It is used for telephone cords, household appliances (fan, video camera), vehicles (VAZ and others), etc. It is this data that is most important when installing cables or.

How to determine the purpose and types of wires by color marking, according to PUE 7:
• Blue – working zero;
• Green is zero protective;
• Black – grounding or “earth”;
• White is the color marking of the phase zero wires.

By the way, different manufacturers There may be different types of designations. For example, the phase cable may be white, pink, yellow, orange, gray, red, so be careful when installing or removing the cords. When connecting phase or socket outlets, make sure that the colors of the cables being connected match.

Marking of individual electrical cables

Each household device uses a unique notation system.

For a laptop keyboard or computer power supply:
1. Red – standard USB VDC, connection cable for the Defender Accord km-4810L keyboard and others.
2. White is for the USB D connector, while green indicates D+.
3. Black – intended for the GND input (available in headphones).

Be careful, the black and red wires are also used to connect the cooling cooler for electrical equipment.

What do the radio wires do by color:
• Black – ground or connection to engine ground.
• Red – power cord.
• Yellow – power, connects with red.
• Blue (if available) – control of the antenna and other functions of the magnetic circuits.

Buy wires the desired type(SIP, mounting, flexible and others) can be found in specialized stores, where the marking is also indicated in the certificate and product passport. The price depends on the type of cord.

Wiring inside the house

Wiring inside the house is carried out only with single-phase lines and copper wires. In electrical circuits used for domestic purposes, the working zero should always be blue! According to the PUE, intra-house lines must be laid with a grounding conductor. In all three-core conductors, made according to GOST, suitable for interior work, ground wire – yellow-green.

If the three-core conductor is flexible PVA type, then the phase conductor is usually brown. For indoor wiring, it is better to use wires made of cast copper. If the conductors are marked with stripes, then a conductor with a stripe of any color except blue and yellow-green is phase.

If the cable does not have a yellow-green conductor, use a conductor with a green stripe as the ground wire. The ground wire may be marked in pure yellow. In cables whose cores are entirely painted, the white wire is the phase wire.

Connection to electric stove

A 220 V household electric stove is connected to a special outlet that can withstand high power. The colors of the conductors are red, green, blue, where red is the phase, green is the ground, blue is the neutral conductor.

There is a nuance in electric stoves and cooking surfaces foreign-made, designed for 220/380 V, connection is made with a four-core cable:
1. blue – zero;
2. yellow-green conductor – grounding;
3. black conductor – phase A;
4. brown conductor – phase B.

When connecting to a single phase network, it is allowed to combine the phase conductors on the electric stove under one contact clamp.

Neutral wire

Neutral conductor is a wire connected to the middle (zero) point electrical system. IN standard scheme connection is a combined zero working and zero protective conductor in a three-phase circuit. The color of the neutral wire is all blue with yellow-green ends or all yellow-green with blue ends.

Wires are marked by color, letters and numbers. GOST until 2009 interpreted the possibilities of marking wires more broadly. Since 2009, the standards have been revised towards a more clear classification of colors and have eliminated notes that make it possible not to mark conductors.

IN national standard 2009 terminology was clarified and the alphanumeric classification was expanded. For electrical circuits until 2009, classic conductor colors were used: yellow, green, red.

In the classic version of three-phase circuits up to 1000 volts, conductors are marked in the following combinations:
• Phase A – L1, yellow – brown recommended.
• Black is recommended in phase B – L2, green.
• Phase C – L3, red – gray recommended.
• Neutral conductor – N blue.
• Combined working neutral with grounding conductor - PEN, blue with yellow-green tips - yellow-green with blue tips.
• Grounding conductor – PE, yellow-green.

This combination does not imply either the direction of rotation or phasing.

A three-core or two-core wire is laid from the distribution box to the switch, depending on what type of switch is installed: single-key or. The phase is broken, not the neutral conductor. If there is a white conductor available, it will be the power supply. The main thing is to maintain consistency and consistency in coloring with other electricians, so that it doesn’t turn out like in Krylov’s fable: “The Swan, the Crayfish and the Pike.”

On sockets, the protective conductor (yellow-green) is most often clamped in the middle part of the device. We maintain polarity, zero worker is on the left, phase is on the right.

But there are surprises from manufacturers, for example, one conductor is yellow-green, while the other two may turn out to be black.

Perhaps the manufacturer decided, if there was a shortage of one color, to use what was available. Don't stop production! Failures and errors happen everywhere. If you come across exactly the same one, it’s up to you to decide where the phase is and where the zero is, you just need to run around with the control.

If the cable is already laid, how to apply markings

Very often you have to deal with such situations when you come to the site, open the panel, and there the connection is made in an unclear way. There is no need to talk at all about the compliance of wire markings with the rules. It is not clear what color the phase is laid out, and where the zero and ground are.

You have to become familiar with the wiring in the panel, junction boxes, etc. It all comes down to one drawback: you have to waste time. What to do in this case? Do not make the connection in a new way.

Unfortunately, even today some electricians use outdated standards during installation work. Because of this, other specialists, during work related to the repair and maintenance of electrical networks, have to look for “phase” and “zero” using a probe.

If it is not possible to buy conductors of the desired color, cables of any color will do. The main thing is that the ends of the cores are correctly marked using heat-shrinkable tubing or colored electrical tape.

In accordance with the rules, it is allowed to carry out color marking not along the entire length, but only at the points of connection to the busbars, that is, at the ends of the cable. To do this, you can mark the wires by color using colored electrical tape or put a heat-shrink tube on the ends of the cable.

Of course, there is no need to change the existing markings of conductors, the installation of which was carried out according to the old GOST. But today, when commissioning electrical installations, only new rules should be used.

We remind you: installation work electric cable require forethought and care from the installer. Be careful!