Brown and blue wire - which one is plus, which is minus? Wire marking by color for the domestic sector

Today, the installation of electrical wiring is unthinkable without the use of conductors in colored insulation. Color marking is not a tribute to fashion and not a marketing ploy of a manufacturer who, as it may seem to someone, wants to present their products in a colorful way.

In fact, this is an urgent need. Firstly, color marking allows you to indicate the purpose of each conductor in a particular group to facilitate their switching. Secondly, the probability of an error during the installation of wires is significantly reduced and, as a result, the occurrence of a short circuit during a trial run or an electric shock during the maintenance and repair of networks.

Certain colors are not chosen randomly. All the variety of colors is reduced to a single standard - PUE. They indicate that the cores of the wires should be identified by color or alphanumeric designations.

As part of this publication, the color marking of wires will be considered. With the adoption of a single standard for the color identification of electrical conductors, the work of switching them has been greatly facilitated. Each vein that has a specific purpose is designated by a unique color: brown, gray, yellow, green, blue, etc.

Color marking is usually carried out along the entire length of the conductor. Identification is also allowed at the ends of the cores and at the connection points, for which colored heat-shrinkable tubes (cambric) or colored electrical tape are used.

Consider how it is performed in a three-phase, single-phase and direct current.

Color of wires and tires at alternating three-phase current

In three-phase networks, busbars and high-voltage bushings of transformers at power stations and substations are painted as follows: wires and busbars with the "A" phase are painted yellow, green with the "B" phase, and red with the "C" phase.

DC network - what color are the plus and minus wires

Beyond networks alternating current In the national economy, DC circuits are used, which are used in the following areas:

• in industry, construction, storage of materials (loading equipment, electric carts, electric cranes);
• in electrified transport (trams, trolleybuses, electric locomotives, motor ships, mining dump trucks);
• at electrical substations (for powering automation and operational protection circuits).

The DC network uses only two wires. In such networks, there is no phase or neutral conductor, but there is only a positive bus (+) and a negative bus (-).

By regulation, wires and rails of positive charge (+) must be colored red, and wires and rails of negative charge (-) must be blue. The middle conductor (M) is indicated in blue.

If a two-wire DC electrical network is created by branching off a three-wire DC circuit, then the positive conductor of the two-wire network is indicated by the same color as the positive conductor of the three-wire circuit with which it is connected.

Colors of wires phase zero earth in wiring

For laying AC electrical networks, multi-core wires in multi-colored insulation are used, which greatly simplifies installation work and eliminate confusion.

Designation of wires by color this is especially true when the wiring is done by one person, and the subsequent maintenance or repair will be handled by another. Otherwise, the latter will have to constantly look for either “phase” or “zero” with the help of a probe.

Those who have worked with old wiring know how annoying it is sometimes. After all, earlier the insulation of the electrical cable used in everyday life was one-color - white or black.

Since the times of the USSR, color coding electrical wiring went through a number of changes until a certain standard was developed. Now each color of the current-carrying conductor determines its purpose in the cable.

Nowadays, the normative document regulating color coding insulated or bare conductors - is PUE 7, where, in accordance with GOST R 50462 "Identification of conductors by colors or numerical designations", only certain colors and designations.

Main task wiring markings is the speed and ease of determining the purpose of the conductors along the entire length, which is one of the main requirements of the PUE.

Consider what colors conductors should have today in AC electrical installations with voltages up to 1000V and with a solidly grounded neutral (most office buildings and residential buildings fall into this category).

Color of zero protective and zero working conductors

Blue color indicates zero working conductors (N). Zero protective (PE) conductor must be painted in yellow-green longitudinal or transverse stripes. This combination of colors should only be used for marking pinching conductors (zero protective).

Combined zero working and zero protective (PEN) - Blue colour along the entire length of the conductor with yellow-green stripes at the ends (at the junctions). It is characteristic that GOST today also allows the opposite color option - yellow-green stripes along the entire length with blue at the ends (at the junctions).

Simply put, designation of neutral wires by color should be:

1. 1) zero working (N) - blue color;
2. 2) zero protective (PE) - yellow-green color;
3. 3) combined (PEN) - yellow-green blue marks at the ends.

Phase wire colors

In accordance with the PUE, when designating phase conductors, preference is given to one of the following colors: black, brown, red, gray, purple, pink, white, orange, turquoise.

A single-phase electrical circuit can be created by branching off a three-phase network. In this case, the phase wire of a single-phase circuit must match the color of the phase conductor of the three-phase network with which it is connected.

Wire color coding must be carried out in such a way that the color of the phase conductor does not match the color of the N-, PE- or PEN-conductor. When using an unmarked cable, colored marks are placed at its end (at the junction). In this case, a colored heat shrink tube (cambric) or colored electrical tape is used for designation.

To save yourself from unnecessary work in the form of leaving marks with electrical tape or tubes, it is enough to correctly determine the color marking of the insulation before buying an electrical cable. You should also purchase it in the right quantity to ensure the same wiring markings throughout the apartment or throughout the house.

If the cable is already laid how to mark

Very often you have to deal with such situations when you come to the object, open the shield, and there the connection is not clear how. There is no need to talk about the correspondence of wire marking with the rules. It is not clear where the phase is, and where is zero and ground. You have to familiarize yourself with the wiring in the shield, junction boxes, etc. It all comes down to one drawback, you have to waste time. How to be in that case? Do not reconnect.

Modern installation of electrical wiring is impossible to imagine without the use of wires in insulation of different colors. Color marking is not done for beauty, it is urgently needed in the electrification of objects. Color marking not only indicates the purpose of each individual wire in a common bundle for ease of connection, but also reduces the risk of wiring errors. Allows you to prevent the likelihood of short circuits during test switching or electric shock during service and repair work ah on the net.

A certain choice of color marking is not accidental, but corresponds to the main standard - PUE. They are prescribed to identify wire cores by color or alphanumeric characters.

Color coding of electrical wires

Installation of lighting networks and power distribution to sockets is carried out using a cable with three conductors.

Multi-colored marking is applied to the entire length of the conductor. It is also possible to identify the ends of the cores and switching points using a multi-colored heat-shrinkable tube (cambric) or colored electrical tape.

We propose to consider how the color marking of conductors is carried out in electrical networks single-phase, three-phase and direct current.

The grounding conductor must be marked yellow-green. In switchboards (RShch), the "ground" must be connected to the ground bus, to the body or the metal door of the shield. In junction boxes, the connection is made to the ground wires of the fixtures and to the ground contacts in the sockets. The "ground" conductor does not need to be connected to a residual current device, therefore, the RCD is recommended to be installed only in those in residential premises where the "old-fashioned" electrical wiring is made with two conductors.

Ground conductor

Zero (neutral)

The "zero" conductor is marked in blue. In the RSH, it is always connected to the zero bus, denoted by the Latin letter N. All blue conductors are connected to this terminal. The zero bus is connected to the electrical input through a metering device (electric meter) or directly, without additional use circuit breaker. In the junction box, all conductors (except the conductor from the switch) of blue color (neutral) are connected together and do not take part in switching the voltage. For three-pole sockets, blue conductors are connected to the contacts marked with the Latin letter N, marked on the back of the socket.

Conductor "zero"

Phase

To designate a "phase" wire, brown, black, red or even white are usually used. In the house switchboard, the phase conductor going to the load consumer is connected to the bottom contact of the RCD or circuit breaker. In switches lighting fixtures the phase conductor is switched, when turned on, the contacts close and the voltage is supplied to the consumer. In phase sockets, the black wire must be connected to the contact marked with the Latin letter L.

With regret, it is worth noting the fact that at present, many electricians, when conducting wiring, are guided by old standards. After that, other electricians, when carrying out service or repair work, have to look for "phase" and "zero" using probes.

Phase wire designations

If it is not possible to purchase conductors of the required colors, cables of various colors can be used. It is important that at the ends of the strands they are correctly marked using heat shrink tubing or colored tape.

Watch a video about the types of wires and cables:

For correct connection wires use their color marking, which allows you to quickly find the desired conductor in the bundle. But not everyone knows as indicated by the phase and zero in the electrician, therefore, colors are often confused, which makes it difficult future renovation wiring. In this article, we will analyze the principles of color marking wires and tell you how to properly breed phase, ground and zero.

Wires must be connected to each other only in strict accordance. If mixed up, a short circuit will occur, which can lead to equipment failure or the cable itself, and in some cases even a fire.

Standard wire colors

Marking allows you to connect wires correctly, quickly find the right contacts and work safely with cables of any type and shape. Marking, according to the PUE, is standard, therefore, knowing the principles of connection, you can work in any country in the world.

Note that the old cables produced under the USSR had one conductor color (usually black, blue or white). To find the desired contact, they had to ring or apply a phase to each wire in turn, which led to unreasonable waste of time and common mistakes(many remember the freshly built Khrushchevs, in which, when you press the bell, front door the light in the bathroom turned on, and when the switch in the bedroom was pressed, the power was lost in the outlet in the hallway).

Various greatly simplified the process of creating wiring, and after a few years became the standardin Russia, EU, USA and other countries of the world.

Earth, zero and phase

In total there are three types of wires: ground, zero and phase. The coloring is applied to the entire wire, so even if you cut the cable in the middle, you can still understand where the contact is.Grounding is indicated as follows:

1. Yellow-green color (in the vast majority of cases).
2. Green or yellow.

In the wiring diagram, grounding is abbreviated as PE.

Note:in blueprints and electrician slang, grounding is often referred to as null protection. Do not confuse it with zero, otherwise a short circuit will occur.

Zero in the cable is indicated in blue-white or just blue, the designation in the diagram is the letter N. Sometimes it is called neutral or zero contact, so be careful not to confuse these concepts.

Now let's figure outis used most often. Here you will have a hard time, because there can be a lot of options. We advise you to go the opposite way - first find the yellow-green ground, then the blue zero, and the wires remaining in the cable will be the phase. It is necessary to connect them according to the colors so that there is no confusion. Most often in three-core systems they are marked brown, but there may be other options:

• black;
• red;
• grey;
• white;
• pink.

On schematic representations the phase is displayed with the letter L. You can detect it with a test screwdriver or a multimeter. When connecting wires, use special clamps or solder them offset from each other so that a short circuit or oxidation of contacts does not occur, followed by a loss of voltage.

The difference between zero and ground

Some novice electricians do not knowand why is it even needed. Let's analyze this issue in more detail. Flows through zero and phase electricity so you can't touch them. The ground also serves to drain the voltage if it breaks through the body of the device. This is a kind of protection, which in last years became mandatory - some devices do not work if they are not grounded.

Attention:do not ignore the grounding requirement - accumulated static electricity or breakdown can damage the device or give you an electric shock.

If you are not sure which of the wires is ground and which is zero, then use the following tips. They will help you decide wire colors:

1. Measure the resistance of the wire - it will be less than 4 ohms (check that there is no voltage on it so as not to burn the multimeter).
2. Find the phase, use a voltmeter to measure the voltage between the expected zero and ground. On ground, the value will be higher than at zero.
3. If you measure the voltage between ground and a grounded device (for example, a battery in a multi-storey building) with a multimeter, then the voltmeter will not determine the voltage. If you measure the voltage between zero and ground, then a certain value will be displayed.

All this is true only for three- or more conductor cables. If there are only two wires in the cable, then by default one of them will be ground (blue), the second phase (black or brown).

Looking for a phase

You already know what color of wires phase, zero, ground. Consider the main question - how to find the phase. If you are going to connect an outlet, then you, in fact, do not care about this issue - there is no difference on which contact to apply phase or zero. But the switch is different.

Attention:in the switch, the phase always opens, and zero comes to the light bulb. This is necessary so that during the repair or replacement of the lamp you are not shocked. The phase must be started up on the lower contact of the cartridge, zero - on the side.

If there are two single-color wires in the wiring, then the easiest way is to find the phase with an indicator - when you touch a bare wire, it starts to glow. Before touching the wire, turn off the power, strip the insulation on the wire (1 cm is enough), spread the wires in different directions so that there is no short circuit. Then turn on the power and touch the indicator to the contact. Thumb hands should be placed on the top of the screwdriver, where the pad is located. After that, the LED on the indicator should light up. This will allow you to find the phase, but the device will not help you figure out between zero and ground. To find out what color is the ground wire in a three-wire wire, you will need to use the above methods.

Conclusion

If you are creating a new wiring, then be sure to comply with the PUE electrical wire marking - this will help you in the subsequent repair of the system, because you can easily identify the wires by color. Use green/yellow for ground, blue for neutral, brown/black/white for live. In cables with a large number of phases, connect the contacts only by color, using the appropriate clamps and heat shrink. If you have to work with old wiring, where the colors do not meet the standard, then first of all look for the phase with an indicator screwdriver. The contact that does not glow will be the desired zero.

When laying wires, follow the rules - they should only run horizontally and vertically. No need to try to save money by dragging them down an incline across the entire wall or ceiling - in the future you simply won’t be able to find them or hook / kill them during repairs, which will lead to serious consequences. Once and for all remember colors of wires in a three-core cable - this will help you in life, because any electrician is faced with repairing sockets, switches, electrical panels, laying new lines, etc.

Novice and experienced electricians prepare before starting work necessary materials, including determine the footage Supplies. The marked color of the selected wire for connecting the phase, ground and zero will help those who assemble the circuit for the first time not to get confused when preparing for events.

factory standards

Traditionally, when creating three-phase networks All cables were colored in accordance with the normative documentation of previous years. In the wiring, which is more than 7 years old, according to the PUE, the following marking was strictly observed:

• Phase A is yellow, a greenish longitudinal vein is possible.
• Phase B - a pronounced green color, sometimes a neon hue.
• Phase C is red.
• Zero - a bluish or neutral gray tone was allowed.

Common three-phase wiring was abbreviated Zh-Z-K.

If you are dealing with the old wiring from the times of the USSR, then the color of the conductors will be only monochrome: black or white. Electricians recommend not to take risks - when turning off, you need to give power and determine the type of wires of the electrical wire using the control.

Since 2011, GOST RF 50462-2009 began to function on the territory of the Russian Federation. It provides new colors for industrial conductors. Shades are allowed for phases: A - classic brownish, B - rich black, C - gray, close to "metallic". But the contrast of such materials turned out to be inconvenient, and electricians, when installing standard systems, still prefer formula K-Ch-S old F-G-K gamma. Bright veins are better visible in any light, the contrast of the design gives a quick understanding of the situation.

The letter designation makes it easier to recognize the nuances of the circuits: A is L or L1, B is only L2. C is L3 and zero is N. Therefore, a knowledgeable craftsman will immediately understand what color the phase wire is when compiling the circuit.

According to generally accepted standards when creating electrical circuits alternating or direct current with the use of conductors with protection, all of the above shades are acceptable.

Many colors of conductors can be used when connecting industrial complicated objects. For domestic use, a standard three-phase version is mounted.

The complete set of the euro socket implies the presence of three components: a bright phase (it can be red, purple, brown or another juicy tone), a blue-blue tint that is safe for a person to zero, and protection in yellow or green colors. Wire marking is recognized only as generally accepted.

Wire color coding

Phase wire color

When wiring or checking old circuits, color identification will speed up the process. For correct connection equipment use the appropriate tone option in accordance with regulatory documents.

In the presence of one phase and zero, the phase part is determined by the brown casing. According to the PUE, you can apply: turquoise, shades of red, purple, gray, orange, pink and monochrome (black earth and other options white color). But zero is blue, and protection with alternating stripes of yellow and green.

Letter designations can be refined using special polymer markers. For the phase, all varieties are used, except for the two-color combination of green yellow color. Such accessories are popular in everyday life, when craftsmen do simple work for themselves, and the most budgetary is a cable with white insulation. In production, connecting the units that users use, strict adherence to GOST and international standards is required: this is the only way to avoid emergency situations.

If you work with a DC network, then there are two buses: + and -. Blue is minus, red is +, middle M is blue. If 3 wires go first, and two branch off from this circuit, then + will be the same color as in the previous permanent network.

There is no grounding in old Soviet-era sockets, so opening similar device the craftsman will see a bluish working zero bus and any other conductor. An outdated PEN grounding system is a risk of electric shock.

The European standard already provides for protection - there are 3 wires in a yellow-green color. In sockets, according to the rules, it is on the left, and in the design of the switch, it is on the bottom.

Neutral wire color

The established colors of the ground wire are determined by the standard: a yellow or yellow-green casing is required. Green stripes stretch along the seam or be transverse. Since the initial work could be guided by the standards of previous years, only yellow or only green marking wires.

In the same way, the earth is marked on the drawing, the connection contacts are indicated. Such cores - zero earthen protective - are designed to reduce the likelihood of electric shock.

Insistence "zero", the second name is neutral, only blue, less often - blue, sometimes with alternating blue-blue stripes. Markup advantage: in the drawing, the neutral option can only be of this shade! In the diagram, it is blue with the N mark. The zero working contact as part of flexible stranded plexuses has light tone, otherwise acceptable bright shade. It is needed to equalize the voltage of different phases.

Why wire marking is needed

Marking applied with insulation or control is convenience for an electrician, quick installation and repair, as well as absolute safety for an employee and a simple layman. They have different purposes:

• Phase - this is the supply of current to the equipment, outlet.
• Zero - assignment to the source.
• The protective zero is connected to "pull" the current during a short circuit and send it "to the ground". The person will be out of danger.

If there are doubts about the correctness of the designations, working with monochrome tires, and other non-standard situations in everyday life and at work, it is necessary to use the equipment to find the desired core wire, ring the network.

A probe, an indicator screwdriver will do. The handle of the tool is made of a dielectric material, and a diode is located inside. The device detects the presence of voltage and its absence. For serious events, other equipment with advanced capabilities is needed. After an accurate determination, use PVC cambric to bring it to GOST. Such an insulating innovation is heat shrink tubing, which can be replaced with duct tape.

When performing such activities, it is imperative to de-energize the system, and clean the ends. Only after the measures taken, you can turn on the current again and proceed with the test. The purpose of the circuit components is established by means of color with new PVC markers. Plastic markers with markings - pointers that bring the wiring in line with accepted standards.

For clarification and designation by means of the color of "earth" and "zero" of the cambric, an ohmmeter is used on the "protection" value will not exceed 4 ohms.

Color coding of wires is needed so that each user can accurately determine the type of network, its level of security. Professionals in emergency situations, thanks to the color coding, will cope with emergency situations.

Marking of cable lines, wires

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

What are the conductors in the socket?

You can deal with the question "what is phase and zero" without delving into the wilds of finding out the structure, advantages and disadvantages in three-phase or five-phase circuits. You can actually disassemble everything on your fingers, revealing the most ordinary home socket, which is placed in an apartment or a private house ten or fifteen years ago. As you can see, this socket is connected to two wires. How to determine zero and phase?

How do wires work in an outlet and why are they needed?

As you can see, there are certain differences between workers and zero. What is the designation of phase and zero? A bluish or blue color is the color of the phase wire, zero is indicated by any other colors, except, of course, blue flowers. It can be yellow, green, black and striped. The current does not flow. If you take it and do not touch the worker, then nothing will happen - there is no potential difference on it (in fact, the network is not ideal, and there may still be a small voltage, but it will be measured at best in millivolts). But with a phase conductor, this will not work. Touching it can result in electrical shock, even fatal. This wire is always energized, current flows to it from generators and transformers and stations. You must always remember that in no case should you touch the working conductor, since a voltage of even a hundred volts can be fatal. And in the socket is two hundred and twenty.

How to determine zero and phase in this case? In the socket, designed according to European standards, there are 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 painted in. But the third wire is called zero protective. It is usually colored yellow or green. It is located in sockets on the left, in switches - from below. The phase wire is on the right and top, respectively. Given such colors and features, it is easy to determine where the phase is, and where is zero, and where is the protective neutral wire. But what is it for?

Why do I need a protective conductor in euro sockets?

If the phase is designed to supply current to the outlet, zero - 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 order, then the protective zero will not take part, it is inactive. But if suddenly somewhere there is either an overvoltage or a short circuit on some parts of the devices, then the current enters places that are usually without its influence, that is, not connected either to the phase or to zero. A person can simply feel an 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 design of the wiring 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. At protective conductor resistance does not exceed a few tenths of one ohm.

Determining the purpose of conductors

How to determine zero and phase? Everyone has come across these concepts in one way or another. Especially when you need to fix the outlet or do the wiring. Therefore, it is necessary to understand exactly where which conductor is. But how to determine zero and phase? It must be remembered that all manipulations of this kind with electricity are dangerous. Therefore, in case of uncertainty in their actions, it is better to consult a specialist. If you already approach the outlet and the wires in it, then you must first completely de-energize the entire apartment. At a minimum, it can save health and life. As mentioned earlier, usually the designation of phase and zero is done using coloring. At correct labeling it won't be hard to tell them apart. Black (or brown) - the color of the phase wire, zero usually has a bluish or bluish tint. If a European standard socket is installed, then the third (protective zero) is made in green or yellow. What 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 marking. They are called "cambric".

Determining conductors with 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. Built-in diode glowing light bulb. The top part of this screwdriver is metal. How to determine zero and phase by this method?

The procedure for performing work when measuring with an indicator screwdriver:

• de-energize the apartment;
• we clean slightly the ends of the wires;
• we separate them to the sides in order 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 a screwdriver by the handle, which has a dielectric coating;
• put your finger (thumb or index) on the contact, which is located on the back of the outlet;
• touch the working end of the indicator to one bare conductor;
• carefully observe the reaction of the screwdriver;
• if the diode caught fire, then we can state with confidence that;
• by 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 a significant disadvantage of this method. With the help of an indicator screwdriver, it is impossible to understand how to determine: phase, zero, ground - where is what in the case of a European outlet.

Method for determining phase and zero using a voltmeter

If the wires are not painted in the appropriate colors, and there is no indicator screwdriver at hand, then you can go the other way. We need a voltmeter (multimeter, tester). It is necessary to set it to the required range - over two hundred volts of alternating current. How can a tester determine the phase? We take one conductor that departs from the device (indicated by V). We attach it to a previously de-energized conductor (any). Then we apply current (turn on the switch). And just fix 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, then this means that we have either a zero or a grounding protective neutral wire in front of us. However, you can use another method that answers the question: "How to determine zero and phase, as well as grounding." To do this, we de-energize the apartment again, fix the V clamp on one of the wires. We also throw the second on any of the three conductors. The voltage is turned 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 the V terminal must be changed (throw it onto another previously unused conductor). We turn on the current again and take the appropriate measurements. Then we carry out the same operation, but again we change the conductor. Now we need to check the results. If the first digit turned out to be greater, it means that we measured the voltage between the phase conductor (on which the V terminal hung) and zero. Accordingly, the second wire will be a protective ground. This method is based on measuring the potential difference.

Exotic ways to determine the phase and zero in the wiring

There are also folk methods”, which do not imply the presence of any special devices. They can only be used in the most extreme cases, as they are associated with increased danger to health and life. For example, the potato method. To do this, a freshly cut piece of potato is put on 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 for a couple of seconds, voltage is applied and they look at the potatoes. If one section near the wire turns blue, then a phase is connected to it.