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Designation L and N in electrics

Each time trying to connect a chandelier or sconce, light sensor or movement, a hob or exhaust fan, a heap thermostat or a LED tape power supply, as well as any other electrical equipment, you can see the following labeling near the connection terminals - L and N.

Let's deal with what the designations of L and N are said in electrics.

As you probably, they yourself guessed this not just arbitrary characters, each of them carries a specific value and performs the role of tips, to properly connect the electrical appliance to the network.

Designation L in electrics

"L" - this labeling came to an electrician from the English language, and it is formed from the first letter of the word "line" (line) - the generally accepted name of the phase wire. Also, if you are more convenient, you can focus on such concepts of English words as Lead (entry wire, lived) or live (under voltage).

Accordingly, the labels and contact connections intended for connecting the phase wire are labeled. In a three-phase network, alphanumeric identification (marking) of phase conductors "L1", "L2" and "L3".

By modern standards (GOST R 50462-2009 (IEC 60446: 2007) acting in Russia, colors phase wires - Brown or black. But often it can occur white, pink, gray or wire of any other color, except blue, white-blue, blue, white and blue or yellow-green.

Designation N in electrician

"N" - marking, formed from the first letter of the word Neutral (neutral) - the generally accepted name of the zero working conductor, in Russia called more often just zero conductor or short zero (zero). In this regard, the English word null (zero) is successful, you can focus on it.

The designation N in the electrician is marked by clamps and contact connections to connect the zero working conductor / zero wire. In this case, this rule acts both in a single-phase and three-phase network.

Wire colors that are labeled zero wire (zero, zero, zero working conductor) Strictly blue (blue) or white-blue (white blue).

Estimation of grounding

If we are talking about the designations of L and N in an electrician, it is impossible not to note yet such a sign - which is also almost always can be seen together with these two labels. This icon marked clamps, terminals or contact connections to connect the wire (PE - Protective Earthing), it is zero protective conductor, grounding, ground.

Generally accepted color marking of zero protective wire - yellow-green. These two colors are reserved only for grounding wires and are not found in the designation of phase or zero.

Unfortunately, often the wiring in our apartments and houses is made with non-compliance with all strict standards and rules of color and alphanumeric labeling for electricians. And know the purpose of marking L and N in electrical equipment, sometimes, not enough, for the correct connection. Therefore, be sure to read our article "How to determine the phase, zero and grounding by yourself, with remedies? ", If you have any doubts, this material will be as impossible by the way.

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The transition to the usual voltage of 220 V was carried out in the years of existence Soviet Union And ended in the late 70s, early 80s. The electrical networks of that time were performed on a two-wire diagram, and the insulation of the wires was used in one-photon, mostly white. In the future, household appliances of increased power, requiring grounding.

The connection circuit gradually changed to the three-wire. GOST 7396.1-89 Standardized the types of force forces by bringing them by European. After the collapse of the USSR, new standards were adopted based on the requirements of the International Electrotechnical Commission. In particular, to improve security when working in electrical networks and simplifying the installation, the color gradation of the wires was introduced.

Normative base

The main document describing the installation requirements of the power grid is GOST R 50462-2009, which is based on the IEC 60446: 2007 standard. It sets out the rules that the color marking of wires must match. They concern the manufacturers of cable products, construction and operating organizations whose activities are related to the installation of electrical networks.

Advanced installation requirements are contained in the rules of the device of electrical installations. They provide the recommended connection order, referring to GOST-P at points related to color gradations.

The need for color separation

The two-wire system implies the presence in the phase and zero network. Fork for such sockets is used flat. The equipment is designed in such a way that the correctness of the connection is not playing. It does not matter to which contact will be supplied by the phase, the instrument will understand independently.

With a three-wire system, the presence of grounding veins is additionally provided. At best, the wrong wire connection will lead to a constant triggering of the protective machine, at worst - damage to equipment and fire. The use of color gradation for lived, eliminates errors when installing and eliminates the need to use special devices designed to measure the resulting voltage.

Three-wire system

Let's look at the incision of the three-core wire, which is used for laying household power grids.

The color of the wires indicates where the phase, zero and earth are located. Additionally, the figure shows typical letters applied in electrical circuits. Taking into your hands such a drawing, you can visually determine the correct connection of the connection.

Let's look at the GOST and see how the color marking shirms in the figure matches the requirements. Paragraph 5.1 of general provisions contains a description of twelve colors to be used for labeling.

Nine colors stand out to designate phase wires, one for zero and two for grounding. The standard provides for the implementation of the grounding wire in the combined yellow-green design. Longitudinal and transverse strokes are allowed, with this preferential color should not occupy more than 70% of the braid area. Separate use of yellow or green in the protective coating is directly prohibited by clause 5.2.1.

The specified scheme is applied with a single-phase connection suitable for most electrical devices. Get confused in it, with a properly labeled wire, almost impossible.

Five-Watering System

For a three-phase connection, five-in-room wires are used. Accordingly, three wires are highlighted for phases, one for neutral or zero and one under protective, grounding. Color marking, as in any AC network, applies similar, in accordance with the requirements of GOST.

In this case will be proper connection Phase conductors. As can be seen in the figure, the protective wire is made in a yellow-green braid, and zero - in blue. For phases used allowed shades.

With the help of five-tier wires, you can connect the 380 V network with a properly performed compaction.

Combined wires

In order to reduce the cost of production and simplify connection, the wires of two or four can also be used, in which the protective core is combined with neutral. In the documentation, they are denoted by PEN abbreviation. As you guessed, it takes shape from alphabetic designations of zero (N) and grounding (PE) wires.

GOST provides for them special color labeling. In length they are painted in the colors of grounding veins, that is, yellow-green. Ends should be necessarily painted in blue, they are also additionally referred to all connectivity.

Because the locations in which the connection is performed in advance is not possible, at these points PEN wires are isolated using an insulating tape or Cambricks. of blue color.

Non-standard wires and marking

By purchasing a new wire, you are of course pay attention to the color marking lived and choose the option where it is applied correctly. What to do in the case when the wiring is already executed, and the colors of the wires do not meet the requirements of the GOST? The output in this case is the same as with the PEN wires. You will have to perform a manual marking, after you decide on the role performed suitable to the equipment by the veins. A simple variant will be the use of color tape of appropriate shades. At a minimum, it is worth identifying a protective and neutral wire.

For professional mounting It is possible to use special cambricks, representing hollow segments insulating material. They are divided into ordinary and heat shrinking. The second does not require the selection of diameter, but do not have the ability to reuse.

Specially made markers are also found, with international alphanumeric designation. They are used on the introductory and distribution shields, For example, in apartment buildings or administrative buildings.

Digital labels, together with the color of the wire, allow you to determine which consumer is supplied.

Additional requirements

Since lines, as well as a layout, can be performed using various cable products, there are a number of rules for their mutual connection. Connecting a three-wire cable to a five-wire routine must be performed in compliance with the color marking from the leading to the slave. Accordingly, the grounding and neutral colors must coincide.

Phase connection, in this case, is performed using the combining bus. On the one hand, three veins are joined to it, on the other hand, one, which is a phase in a new branch.

When installing household power grids, according to safety requirements, it is prohibited to use wiring with aluminum, as well as large conductors. Only cable with solid copper residential should be used.

Three-wire DC system

In DC systems, a three-wire system is also used, but the destination of the wires is different. The separation is performed on the positive, minus and protective. According to GOST in such networks, the following color marking is applied:

• Plus - brown;
• Minus - gray;
• Zero - blue.

Since separately the wires under the DC systems are irrationally, the specified color gradation is used mainly for the color of conductive tires.

Finally

As you can see, the colors of the wires in the electrician are not a whim of the manufacturer, but a measure aimed at ensuring safety requirements. Upon compliance with the installation rules, it is much easier to maintain such networks, and not only an electrician specialist can understand the connection, but we are with you.

Video on the topic

Each time I install a socket or connect some stationary device the question arises about what the color of the wire is the phase? Or is it the Earth? The confusion adds that far from all cables - these are our native VG-3 with white, blue and yellow-green wires. There are both Chinese with combinations of gray + brown + white, there are also complex stranded cables that can only be understood by electrician directory.

In everyday life, all these encodings take it now, so we will focus on the simplest wiring. Simple - this is a cable of three lived and household task, for example, setting the outlet.

Standard Household Wire With White, Blue and Gray-Green Color

Encoding, marking and history

The idea of \u200b\u200bsplitting the wires in colors is not Nova - the first experiments, as old textbooks draw us, were carried out with multi-colored terminals and wires. All the same unmandant simplicity stayed in cars - blue and red wire is hardly confused. True, it sometimes happens black, but this is a completely different story.

When studying the wiring, the most important to determine the color of the wire is not a phase, but the earth and zero, the phase can always be found using a detector dilapidation or (practically) of any diode. But to confuse the color of the earth and zero sometimes it becomes just dangerous, and determine what color the wire of the zero land is necessary in advance.

Phase wire color

As previously specified, it is not necessary to determine the particular phase in color - almost always have access to a particular tool to determine. Some "zoo" in colors are observed due to the fact that there are extended, not household standards for the color differentiation of wires, they are used by real electrics. For example, a brown color says that the wire is designed for sockets, and red - for lighting. The load and permissible work parameters depends on it.

Color wire land

Grounding the most non-alternative wire, it always has a yellow-green color. There are deviations, for example, purely yellow - when the wire is imported. The network is written that there is a yellow-green-blue color of the wire, which denote the combined working zero and land.

Color zero wire

A minus has a small choice of colors - usually it is a blue wire that is practically in any cable, or (very rarely) red / cherry. As it was said about the Earth, it is not recommended to confuse these wires.

Conclusion

Fix the total color scheme:

• Earth - the color of the wires yellow-green or yellow color of the wire;
• Zero - blue color;
• Phase - Wire color white, red, brown and any other unfamiliar.

In order to facilitate the installation of electrical wiring, all cable-conducting products have the appropriate multi-colored labeling. As a rule, in houses or apartments, the lighting device, the connection of the sockets is performed using three wires. Each of them has its own destiny in the home electrical network. Therefore, the designation of the color of the wires of the Earth has great importance. Due to this, installation and subsequent repair is significantly reduced. Thanks to color marking, any type of connection does not represent a special complexity.

Ground wire

To designate the grounding wire in most cases, yellow green color. Sometimes you can meet the conductors with insulation only yellow color. Even less often used light green color. Typically, such wires are marked with the symbols of re. However, if the ground wire is combined with neutral, it is indicated as Pen. It is painted in a green-yellow color, and at the ends there is a blue braid.

In the distribution panel, the ground wire is connected to a special tire, or to the body and metal door. IN distribution box The compound is performed with similar wires provided in luminaires and outlets equipped with special grounding contacts. Grounding wire does not need to connect to a protective disconnection device (UZO), so such safety devices are used where only two wires are used for the wiring.

Zero conductor (neutral)

For zero conductor or neutral, blue color is traditionally used. Connecting in a camshaft is carried out through a special zero tire, denoted by the N symbol. All wires having blue are connected to this tire.

The tire itself is connected to entering through. In some cases, the connection can be carried out directly, without any additional automatic devices.

In the junction box, all neutral wires of blue are connected together and do not take part in switching. The exception is the wire moving from the switch. Connection blue wires It is performed using a special zero contact indicated by the letter N. This marking is affixed on the back of each outlet.

Color phase wire

Phase does not have any accurate designation. Quite often there are black, brown, red and other colors, differing from green, yellow and blue. In the distribution panel installed in the apartment, the connection of the phase wire, which comes from the consumer, is performed with the contact of the circuit breaker located below. In other schemes, this conductor can connect to the protective shutdown device.

In the switches, the phase directly participates in switching. With it, there is a closure and opening of the contact - switching on and off. Thus, the voltage is supplied to consumers, and if necessary, the termination of this feed. In the outlets, the phase conductor connects to the contact with L. marking.

Wiring

Sometimes there are situations when it is required to determine the purpose of this or that wire in the absence of marking on it. The simplest and most common way is. With its help, you can accurately establish which wire will be phase, and which is zero. First you need to turn off the power supply on the shield. After that, the ends of two conductors are cleaned and bred apart from each other. Then you need to turn on the supply of electricity and determine the indicator assignment of each wire. If the bulb caught fire when contacting the residential is a phase. So the other lived will be neutral.

If there is a ground wire in the wiring, it is recommended to use the multimeter. This device is equipped with two tentacles. Initially, the AC measurement is set in the range of more than 220 volts on the corresponding mark. One tental is fixed at the end of the phase wire, and the second is determined earthing or zero. In the case of contact with zero, a 220 volt voltage will be displayed on the instrument display. When touching the grounding wire, the voltage will be noticeably lower.

Marking

There is not only the color of the wires of the phase, zero, land, but also other types of labeling, primarily alphabetic and digital designations. The first letter A indicates the material of the wire - aluminum. In the absence of this letter, the core material will be copper.

Main marking of wires in the electrics:

• Aa - corresponds to stranded aluminum cable With an additional braid from the same material.
• AC is an additional lead braid.
• B - the presence of protection against moisture and additional braid from two-layer steel.
• BN - non-combustible cable braid.
• G - no protective shell.
• P is a shell of rubber.
• HP is a rubber shell of non-combustible material.

In order to correctly read and understand what the same scheme or the drawing associated with electricity means, you need to know how icons and symbols depicted on them are decrypted. A large number of information contain letters of elements in electrical circuitsDefined different regulatory documents. All of them are displayed by Latin characters in the form of one or two letters.

SingleBook symbolism elements

Subscriber codes corresponding to separate species The elements that are most widely used in electrical circuits are combined into groups indicated by one character. Letter notation correspond to GOST 2.710-81. For example, the letter "A" refers to a group of "devices" consisting of lasers, amplifiers, telecommunication devices and others.

Similarly, a group denoted by the "B" symbol is decrypted. It consists of devices that convert non-electrical values \u200b\u200binto electrical, where generators and power supplies do not include. This group is complemented by analog or multi-digit converters, as well as sensors for instructions or measurements. The components included in the group are presented by microphones, loudspeakers, pickups, ionizing radiation detectors, thermoelectric sensitive elements, etc.

All letter notities corresponding to the most common elements are combined into a special table:

In addition, Special characters are defined in GUT 2.710-81 to designate each element.

Conditional graphic designations of electronic components in the schemes

And in everyday life we \u200b\u200buse, as a rule, single-phase. This is achieved by connecting our wiring to one of the three phase wires (Figure 1), with which the phase comes to the apartment to us, for further consideration of the material, deeply indifferent. Since this example is very schematic, one should briefly consider the physical meaning of such a connection (Figure 2).

Electric current occurs in the presence of a closed electrical circuit, which consists of a winding (Lt) of a substation transformer (1), a connecting line (2), the electrical wiring of our apartment (3). (Here is the designation of the phase L, zero - n).

Another moment - for this chain to flow, at least one electricity consumer RN should be included in the apartment. Otherwise, the current will not be, but the phase voltage remains.

One of the ends of the winding Lt on the substation is grounded, that is, has electrical contact with the soil (ZML). The wire that comes from this point is zero, the other - phase.

From here, another obvious practical conclusion: the voltage between the "zero" and "land" will be close to zero value (determined by the resistance of the ground), and the "land" is "phase", in our case 220 volts.

In addition, if hypothetically ( In practice it is impossible to do it!) Ground the zero wire in the apartment, turning it off from the substation (Fig. 3), the voltage "phase" - "zero" we will have the same 220 volts.

What is the phase and zero figured out. Let's talk about grounding. The physical meaning of him, I think already clear, so I propose to look at it from a practical point of view.

If it occurs for any reasons for electrical contact between the phase and conductive (metal, for example), the electrical appliance body appears on the latter.

When touched this body, an electric current flowing through the body can occur. This is due to the presence of electrical contact between the body and the "earth" (Fig. 4). The smaller the resistance of this contact (wet or metal floor, direct contact building construction With natural earthing (heating batteries, metal water pipes) So much danger threatens.

The solution to such a problem is to ground the housing (Figure 5), while the dangerous current "will leave" on the ground chain.

Constructively implementing this method of protection against defeat electric shock For apartments, office premises It consists in the laying of a separate grounding conductor Ree (Fig. 6), which is subsequently grounded in one way or another.

How it is done - the topic for a separate conversation, for example, in a private house you can independently make a grounding contour. Exist various options With its advantages, disadvantages, but for further understanding of this material they are not fundamental, as I propose to consider several purely practical issues.

How to determine the phase and zero

Where is the phase where zero is a question that occurs when connecting any electrical device.

To begin with, let's look at how to find a phase. The easiest way to make it an indicator screwdriver (Figure 7).

Conductive sting indicator screwdriver (1) touch the controlled section of the electrical circuit (during operation the contact of this part of the screwdriver with the body is not allowed!), Turning to the contact site 3, the luminescence of the indicator 2 indicates the presence of a phase.

In addition to the indicator screwdriver, the phase can be checked by a multimeter (tester), though it is more laborious. For this, the multimeter should be translated into the measurement mode of alternating voltage with the limit of more than 220 volts. One multimeter probe (what is indifferent) concern the area of \u200b\u200bthe measured chain, another - natural earthing (heating battery, metal water pipes). In the indications of the multimeter corresponding to the voltage of the network (about 220 V), a phase (Fig.8 scheme) is present on the measured section of the chain).

I draw your attention - if the measurements performed show no phase to argue that this zero is impossible. Example in Figure 9.

1. Now at point 1 phase is not.
2. When the switch is closed, it appears.

Therefore, you should check all possible options.

I want to notice that if there is a grounding wire in the wiring, it is impossible to distinguish it from the zero conductor using the zero conductor using the method of electrical measurements within the apartment. As a rule, the wire that completed grounding is yellow green, but it is better to make sure that it is visually visually, for example, remove the cover of the socket and see which wire is connected to grounding contacts.

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In the process independent installation and connecting electrical equipment (this can be various lamps, ventilation, electric stove, etc.) It can be noted that the switching terminals are indicated by letters L, N, PE. Of particular importance here is marked L and N. In addition to the designation of wires in the electrician according to the letters, they are placed in isolation of various colors.

This greatly simplifies the procedure for determining where the phase, land or zero wire is located. To the installed device is able to work in normal mode, each of these wires must be connected to the appropriate terminal.

Wire designation in electrician by letters

Electrical communications in the household and industrial sphere are organized by insulated cables within which conductive veins are located. They differ from each other with color insulation and marking. Designation L and N in electrics It makes it possible for an order to accelerate the implementation of assembly and repair activities.

Application of this marking regulates a special GOST R 50462.: This applies to the electrical installations where voltage up to 1000 V.

As a rule, they are completed with a deaf-free neutral. Often electrical equipment this type Have residential, administrative and economic objects. During the installation of electrical networks in the buildings of this type, it is necessary to understand well in color and alphabetic directions.

Phase designation (L)

AC network includes wires under voltage. The correct name is "phase". This word has English roots, and translates as "line" or "active wire". Phase veins carry a special danger to human health and property. For safe operation They are covered with reliable insulation.

The use of bare wires under voltage is fraught with the following consequences:

1. 1. The defeat of the current of people. It may be burns, injuries and even death.
2. 2. The emergence of fires.
3. 3. Split equipment.

For hire designation in electrics Phase veins are marked with the letter "L". This is a reduction english term "Line", or "Line" (another name of phase wires).

There are other versions of the origin of this labeling. Some experts believe that the words "LEAD" have become a prototype (linked) and Live (indication of voltage). Such marking is also used to indicate clamps and terminals to which linear wires must be switched. For example, in three-phase networks each of the lines is marked by another corresponding number (L1, L2 and L3).

Existing domestic standards governing the designation of the phase and zero in the electricity (GOST R 50462-2009), prescribe linear veins into brown or black isolation. Although in practice, the phase wires can be white, pink, gray, etc. In this case, it all depends on the manufacturer and insulating material.

Zero notation (N)

For the labeling of neutral or zero working, the network uses the letter "N". This is a reduction in the term neutral (translated - neutral). So around the world, it is customary called a zero conductor. In our country, they mainly use the word "zero".

Most likely, the word NULL is taken as the basis. The letter "n" in the scheme indicates contacts or terminals designed to switch the zero core. Such designation is accepted for single-phase, and for three-phase schemes. As a color designation of the zero wire, a blue or white-blue (white-blue) isolation is used.

Ground designation (PE)

In addition to the designation of the phase and zero, the electrician also uses a special implication of PE (Protective Earthing) for grounding wire. As a rule, they are always part of the cable, along with zero and phase veins. Similarly, contacts and clamps are also marked, intended for switching with grounding zero wire.

For the convenience of mounting veins for grounding placed in yellow-green isolation. House master Must understand that these colors always indicate only grounding wires. To designate the phase and zero in the electrician, yellow and green is never used.

As practice shows, the organization of electrical networks in the buildings of the residential sector is sometimes allowed violations of generally accepted standards for using the color of isolation and the corresponding alphanumeric marking. In this case, it is not always enough to have the ability to decipher the designations L, N or RE.

To connect electrical equipment to be really safe, it is necessary to check the compliance with the labeling of the real position of things. To do this, use special devices (testers) or sweater devices. In the absence of experience of such works for its own security, it is better to invite an experienced electrician with the corresponding tolerance.

Designation L and N in electrics

Phase designation and zero in electrics It introduced so that the electrical networks can be safe and easy to use. For this is used special letter marking (L and N) and isolation of the appropriate color. Veins can also occur with labeling of a yellow-green color: thus marked ground wires.

In addition, the same letter notities are applied on connecting contacts and terminals. All that will be needed to do during the installation of an electrical appliance is to bring each of the wires to the terminal. For reinsurance, each of the wires is desirable to check the tester.