Phase, neutral, ground: wire color code from A to Z. Wire colors - a hint for the correct connection Designation on sockets l and n

Almost everyone who has dealt with electrical wiring, I noticed that wires in insulation can have a different color. But few people know that this action makes it easier to install electrical wiring, and there are even special rules electrical installations, following which you can significantly reduce the risk of tragic consequences when working with electricity. So what is the essence of color designations and what they mean - the answers to these questions will be given below.

The main task of marking wire insulation

First of all, the wires denote certain colors to ensure safety during work. In assigning a color for each wire, PUE standards (rules for electrical installations) and international European standards are applied. Every electrician can special efforts distinguish, what voltage is(or not) each wire, and also determine where the phase, zero and ground are located.

Of course, if we take a network connection as an example single-gang switch, it will not be difficult to determine the purpose of each wire without color marking. But if we consider the connection of the switchboard, then here we cannot do without special designations. Indeed, in the event of an incorrect connection of current-carrying parts, a short circuit may occur, the wiring will begin to heat up (and, as a result, a fire will occur), and in the worst case, defeat electric shock human installer or people in the vicinity.

In the modern edition of the PUE, it is proposed to maintain not only a color designation, but also an alphabetic one, which greatly facilitates work in electrical installations.

The concept of phase and zero in electrics

Before considering color coding, you must first understand the concepts of phase and zero in electrical wiring.

Letter designations are used on electrical diagrams.

For the correct conduct electrical work it is necessary to impeccably follow the rules for connecting current-carrying parts, respectively, all the wires of the circuit must differ markedly from each other. The question becomes reasonable about what color the phase and zero in electricity are indicated. Below are descriptions of each case separately..

Wire colors phase, zero, ground

As mentioned earlier, the coloring of wires in electrics at manufacturing plants is carried out in accordance with the PUE.

Ground wire designation

Ground wire usually denoted by yellow, green and yellow-green colors. Manufacturers can apply stripes of yellow-green color - both in the longitudinal and transverse directions. In addition, it is recommended to apply letter marking. However, the applied letter marking does not exclude color marking. Color designation, according to the PUE, is mandatory. On the example of a switchboard, this wire is connected to the ground bus, housing or metal door.

Zero wire

Speaking of zero, it should not be confused with grounding. Designated in blue or white-blue. But in some cases, the ground wire is aligned with zero. Then it is dyed green-yellow, and there is always a blue braid at the ends. In both single-phase and three-phase circuits, only one neutral wire is used. This is due to the fact that in a three-phase circuit, the maximum shift of one phase can be 120 °, which allows you to use one neutral wire.

Phase wire designation

Depending on the type of wiring, an AC circuit can be either single-phase or have three phases. Let's consider both of these cases separately.

• Single phase wiring

It is used in networks with a voltage of 220 W. Most often, the phase wire is painted black, brown or White color, however, you can also find other wire markings: brown, gray, purple, pink, orange or turquoise. It is also customary to letter L. This is necessary not only on the diagrams, but also in poor lighting conditions or if the wires were covered with dust.

Due to the fact that it is the phase that poses the greatest danger during the work, it is these parts that have the most bright color for quick identification and subsequent more accurate actions with them.

• Three phase wiring

Used in networks with a voltage of 380 W. Previously, all wires and buses in three-phase network were painted in yellow, green and red colors (Ж-З-К), which respectively designated phases A, B, C. These designations presented difficulties due to the similarity of the yellow-green marking of ground wires. Therefore, according to the PUE, from January 1, 2011, new standards were introduced, where the phases are designated L 1, L 2 and L 3, while each has brown, black and gray colors(K-W-S).

On the example of a three-wire wire. Three-core cable wire colors: blue, brown and yellow-green. Brown is phase, blue is zero, and yellow-green is ground.

These were the color options for AC networks.

Coloring of wires in DC networks

In networks with direct current a different color and letter marking of wires and tires is used. The fundamental difference here the absence of zero and phase in the usual sense is considered. This wiring uses a positive conductor, indicated by red and a "+" sign, and a negative conductor of blue color with the sign "-", as well as a zero bus blue color, which is denoted Latin letter M.

Not all people carrying out installation work electrical networks, follow established rules markings. Therefore, before proceeding with the installation, you should first check the presence of current in the wires with a multimeter or a conventional indicator screwdriver. In the future, mark the wires with the required color using colored electrical tape or special heat crimps. Also have special devices allowing letter marking.

Anyone who has ever dealt with wires and electrics noticed that conductors always have different color isolation. 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, therefore, probably, bright colours. 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 large quantity 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 labeling 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.

Get a multimeter and/or 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 plastic handles, gently touch the metal rod of one probe to the found phase wire, the second - to the assumed zero. The screen should show 220 V or 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 touch the phase again, with the second - to the intended ground. If the instrument readings are lower than during the first measurement, the “ground” is 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 in best case equipment failure, but injury and fire may result.

Very few people understand the essence of electricity. Such concepts as "electric current", "voltage", "phase" and "zero" are a dark forest for the majority, although we encounter them every day. Let's get a grain of useful knowledge and figure out what a phase and zero in electricity are. To teach electricity from scratch, we need to understand the fundamental concepts. We are primarily interested in electric current and electric charge.

Electric current and electric charge

Electric charge is a physical scalar quantity that determines the ability of bodies to be a source of electromagnetic fields. The carrier of the smallest or elementary electric charge is an electron. Its charge is approximately -1.6 times 10 to the minus nineteenth power of Coulomb.

Electron charge - the minimum electric charge (quantum, portion of charge) that occurs in nature in free long-lived particles.

Charges are conditionally divided into positive and negative. For example, if we rub an ebonite stick on wool, it will acquire a negative electrical charge (an excess of electrons that were captured by the atoms of the stick upon contact with the wool).

The same nature has static electricity on the hair, only in this case the charge is positive (the hair loses electrons).

main view alternating current is an sinusoidal current . This is such a current that first increases in one direction, reaching a maximum (amplitude) begins to decrease, at some point it becomes zero and rises again, but in a different direction.

Directly about the mysterious phase and zero

We all heard about the phase, three phases, zero and grounding.

The simplest case electrical circuit – single phase circuit . It has only three wires. On one of the wires, the current flows to the consumer (let it be an iron or a hair dryer), and on the other, it returns back. The third wire in a single-phase network is ground (or ground).

The ground wire does not carry a load, but serves as a kind of fuse. In case something gets out of hand, grounding helps prevent electric shock. Through this wire, excess electricity is diverted or "drains" into the ground.

The wire carrying current to the device is called phase , and the wire through which the current returns - zero.

So, why do we need zero in electricity? Yes, for the same as the phase! Through the phase wire, the current flows to the consumer, and through the zero wire, it is diverted to reverse direction. The network through which the alternating current is distributed is three-phase. It consists of three phase wires and one reverse.

It is through such a network that the current goes to our apartments. Approaching directly to the consumer (apartments), the current is divided into phases, and each of the phases is given zero. The frequency of current direction change in the CIS countries is 50 Hz.

AT different countries there are different voltage and frequency standards in the network. For example, a typical household outlet in the United States is supplied with alternating current with a voltage of 100-127 volts and a frequency of 60 hertz.

The phase and zero wires must not be confused. Otherwise, you can arrange a short circuit in the circuit. To prevent this from happening and you do not confuse anything, the wires have acquired a different color.

What color are the phase and zero indicated in electricity? The zero is usually blue or cyan, while the phase is white, black, or brown. The ground wire also has its own color - yellow-green.

So, today we learned what the concepts of “phase” and “zero” mean in electricity. We will be just happy if this information was new and interesting for someone. Now, when you hear something about electricity, phase, zero and earth, you will already know what it is about. Finally, we remind you that if you suddenly need to calculate a three-phase AC circuit, you can safely contact . With the help of our specialists, even the wildest and difficult task will be "too tough" for you.

The ability to read wiring diagrams is an important component, without which it is impossible to become a specialist in the field of electrical work. Every novice electrician must know how sockets, switches, switching devices and even an electricity meter are indicated on the wiring project in accordance with GOST. Next, we will provide readers of the site with the conventions in electrical diagrams both graphic and alphabetic.

Graphic

As for the graphic designation of all the elements used in the diagram, we will provide this overview in the form of tables in which the products will be grouped according to their purpose.

In the first table you can see how electrical boxes, boards, cabinets and panels are marked on the wiring diagrams:

The next thing you should know is the symbol for power sockets and switches (including walk-throughs) on single line diagrams apartments and private houses:

As for lighting elements, fixtures and lamps according to GOST are indicated as follows:

In more complex schemes where electric motors are used, elements such as:

It is also useful to know how transformers and chokes are graphically indicated on circuit diagrams:

Electrical measuring instruments according to GOST have the following graphic designation in the drawings:

And here, by the way, is a table useful for beginner electricians, which shows how the ground loop looks on the wiring plan, as well as the power line itself:

In addition, on the diagrams you can see a wavy or straight line, “+” and “-”, which indicate the type of current, voltage and pulse shape:

In more complex automation schemes, you may encounter incomprehensible graphic symbols like contact connections. Remember how these devices are indicated on the wiring diagrams:

In addition, you should be aware of how radio elements look on projects (diodes, resistors, transistors, etc.):

That's all conditionally graphic designations in electrical circuits of power circuits and lighting. As you yourself have already seen, there are quite a lot of components and you can remember how each is designated only with experience. Therefore, we recommend that you save all these tables for yourself, so that when reading the wiring layout of a house or apartment, you can immediately determine what kind of circuit element is in a certain place.

Interesting video

In order to correctly read and understand what this or that diagram or drawing related to electricity means, you need to know how the icons and symbols depicted on them are deciphered. A large number of information contain letter designations of elements in electrical circuits, determined by various normative documents. All of them are displayed in Latin characters in the form of one or two letters.

Single-letter symbolism of elements

Letter codes corresponding to individual types of elements most widely used in electrical circuits are combined into groups designated by one symbol. Letter designations correspond to GOST 2.710-81. For example, the letter "A" refers to the "Devices" group, which consists of lasers, amplifiers, telecontrol devices, and others.

In the same way, the group denoted by the symbol "B" is deciphered. It consists of devices that convert non-electric quantities into electrical quantities, which do not include generators and power supplies. This group is complemented by analog or multi-digit transducers, as well as sensors for indications or measurements. The components themselves included in the group are represented by microphones, loudspeakers, sound pickups, ionizing radiation detectors, thermoelectric sensing elements, etc.

All letter designations corresponding to the most common elements are combined in a special table for ease of use:

In addition, GOST 2.710-81 defines special symbols to designate each element.

Conventional graphic designations of electronic components in circuits