What color is marked phase zero and earth. Schematic designation of phase and zero in English. How to find phase, ground and zero

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

In electrics, it is customary to distinguish wires by color. This greatly simplifies and speeds up the work: you see a set of wires of different colors and, by color, you can guess which one is intended for what. But, if the wiring is not factory and it was not you who did it, before starting work, you must definitely check whether the colors correspond to the intended purpose.

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

Ground wire color code

According to the latest rules, wiring in a house or apartment must be grounded. In recent years, all household and construction equipment has been produced with a ground wire. Moreover, the factory warranty is preserved only if the power supply is supplied with a working ground.

In order not to be confused, it is customary to use a yellow-green color for the ground wire. A rigid single-core wire has a green base color with a yellow stripe, and a soft stranded wire has a main field of yellow color with a green longitudinal stripe. Occasionally there may be instances with horizontal stripes or just green, but this is not a standard.

Ground wire color - solid and stranded

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

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

Neutral color

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

Neutral color - blue or light blue

In cables with flexible stranded wires, as a rule, lighter shades are used, and solid solid conductors have a sheath of darker, saturated tones.

Phase color

With phase conductors, it is somewhat more complicated. They are dyed in different colors. Excluded are already used - green, yellow and blue - and all the rest can be present. When working with these wires, you must be especially careful and attentive, because it is on them that voltage is present.

Wire color coding: what color is the phase - possible options

So, the most common color marking of phase wires is red, white and black. It can also be brown, turquoise orange, pink, purple, gray.

On the diagrams and terminals, phase wires are signed with the Latin letter L, in multi-phase networks there is a phase number next to it (L1, L2, L3). On cables with several phases, they have a different color. It's easier when distributing.

How to determine if the wires are connected correctly

When trying to install an additional outlet, connect a chandelier, household appliances, you need to know which wire is phase, which is zero, and which is grounding. If the connection is incorrect, the equipment fails, and careless touching of current-carrying wires can end sadly.

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

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

To check, you will need special tools or measuring instruments:

• indicator screwdriver;
• multimeter or tester.

You can find the phase wire using an indicator screwdriver; you will need a tester or multimeter to determine zero and neutral.

Checking with an indicator

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

Using an indicator screwdriver, you can find the phases. We touch the bare conductor with the metal part (if necessary, press the button) and see if the LED is on. Lit - this is a phase. Off - neutral or ground.

We work carefully, with one hand. The second one does not touch walls or metal objects (pipes, for example). If the wires in the cable under test are long and flexible, you can hold them with your other hand by the insulation (keep away from the bare ends).

Checking with a multimeter or tester

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

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

To facilitate the installation of electrical wiring, the cables are made with multi-colored wire markings. Installation of a lighting network and power supply to sockets involves the use of a cable with three wires.

The use of this color system significantly reduces the time for repairs, connecting sockets and. Also, this scheme minimizes the requirements for the qualification of the installer. This means that almost any adult man is able to carry out, for example, the installation of a lamp.

In this article, we will look at how ground, zero and phase are designated. As well as other color markings of wires.

Ground Color

The color of the ground wire, "ground" - almost always marked in yellow-green, less often there are windings both completely yellow and light green. The wire may be marked "PE". You can also find green-yellow wires marked "PEN" and with a blue braid at the ends of the wire at the attachment points - this is grounding combined with neutral.

In the switchboard (RSH) it is worth connecting to the ground bus, to the body and the metal door of the shield. As for the junction box, there the connection goes to the ground wires from the lamps and from the ground contacts of the sockets. The "ground" wire does not need to be connected to the RCD (residual current device), in connection with this, the RCD is installed in houses and apartments, since usually the wiring is done with only two wires. Grounding designation on the diagrams:

Conventional ground(1) Clear ground(2) Safety ground(3) Chassis ground(4) DC ground(5)

Color zero, neutral

Zero wire - must be of blue color. In the switchboard, it must be connected to the zero bus, which is indicated by the Latin letter N. All blue wires must be connected to it. The bus is connected to the input by means of a meter or directly, without additional installation of the machine. In the distribution box, all wires (except for the wire from the switch) of blue color (neutral) are connected and do not participate in switching. To the sockets, the blue “zero” wires are connected to the contact, which is indicated by the letter N, which is marked on the back of the sockets.

Phase color

The designation of the phase wire is not so clear. It can be either brown, or black, or red, or other colors. Besides blue, green and yellow. In the apartment switchboard, the phase wire coming from the load consumer is connected to the lower contact of the circuit breaker or to the RCD. In the switches, the phase wire is switched, during shutdown, the contact closes and voltage is supplied to consumers. In phase sockets, the black wire must be connected to the contact, which is marked with the letter L.

How to find ground, neutral and phase in the absence of a designation

If there is no color marking of the wires, then it is possible to determine the phase, upon contact with it, the screwdriver indicator will light up, but not on the neutral and ground wires. You can use a multimeter to find ground and neutral. We find the phase with a screwdriver, fix one contact of the multimeter on it and “probe” the other contact of the wire, if the multimeter showed 220 volts, this is neutral, if the values ​​\u200b\u200bare below 220, then grounding.

Letter and number wire markings

The first letter "A" denotes aluminum as the core material, in the absence of this letter, the core is copper.

The letters "AA" denote a multi-core cable with an aluminum core and an additional braid of it.

"AC" is indicated in the case of an additional lead braid.

The letter "B" is present if the cable is waterproof and it has an additional double-layer steel braid.

"Bn" cable braid does not support combustion.

"B" PVC sheath.

"G" does not have a protective shell.

"g" (lowercase) naked waterproof.

"K" control cable wrapped with wire under the top sheath.

"R" rubber sheath.

"HP" non-flammable rubber sheath.

Wire colors abroad

The color marking of wires in Ukraine, Russia, Belarus, Singapore, Kazakhstan, China, Hong Kong and in the countries of the European Union is the same: Ground wire - Green-yellow

Neutral wire - blue

phases are marked with different colors

The neutral designation is black in South Africa, India, Pakistan, England, but this is the case with old wiring.

currently neutral blue.

In Australia, it can be blue and black.

In the USA and Canada it is designated as white. Also in the USA you can find gray markings.

The ground wire is yellow, green, yellow-green everywhere, and in some countries it may be without insulation.

Other wire colors are used for phases and may be different, except for the colors indicating other wires.

Individual wires-cores that make up electrical cables have insulation of certain colors. GOST R 50462-2009 regulates the color of insulation, this document shows the features of n and l marking in electrics in order to simplify the work of craftsmen at large facilities and ensure safety during the repair process. Those who decide to repair electrical appliances on their own or do other similar work should also know what color the ground, phase and zero wires are.

Features of the color of the cores

To avoid errors, the requirements of the PUE describe the colors of all the main electrical wires. If an experienced electrician was engaged in commissioning work, following the rules of the PUE and the corresponding GOSTs, for self-repair, neither an indicator screwdriver nor other devices that determine the purpose of a particular core will be needed.

Color marking in electrics according to GOST

grounding

The yellow/green wire is ground. In the circuit diagrams, the neutral conductors are marked with the letters PE. In some houses of old buildings, there are PEN wires in which grounding is combined with a zero core. If the cable was pulled according to the rules, wires with blue insulation were selected, and only the ends and places of twists were yellow-green (thermotubes were put on them). The thickness of the "zero" and grounding can be different. Often the thickness of these two cores is less than the thickness of the phase core, this occurs when connecting portable devices.

When it comes to laying electrical wiring in multi-storey buildings and industrial premises, the PUE and GOST 18714-81 standards come into force, prescribing the mandatory arrangement of protective grounding. Grounding must have a minimum resistance in order to compensate for the consequences of faults on the line and prevent harm to human health. That is, compliance with the color marking standards for PUE wires is of paramount importance.

"Zero"

What color is the neutral wire? Electrical standards dictate that its insulation may be blue, blue with a white stripe, or light blue. Such a marking will be present in a cable with any number of cores. In circuit diagrams, "zero" is marked with the letter N, the circuit is closed on it. Sometimes it is called "minus", and phase - "plus".

"Phase"

The color of the phase is something that is of paramount importance for an electrician: handling conductors requires care and knowledge. The slightest touch of the phase can lead to injury. There are a lot of colors for phase wires marked in the form of the letter L in the wiring, the ban applies only to the use of blue, yellow and green colors. If the cable is three-phase, the serial number of the core is added to the letter L.

When a single-phase circuit is separated from a three-phase circuit, electricians use cables with exactly the same color, watching the color of the phase and zero in the wire. Before starting work, they determine for themselves how different cores will be connected, and in the future they follow the chosen color. Sometimes thermocambrics are fused on them or several turns of colored corresponding electrical tape are wound.

According to GOST:

• black phase wires are used in power circuits operating with direct and alternating current;
• red color - used in control circuits designed for alternating current;
• with orange color - found with interlock control circuits powered from external sources.

How to determine the purpose of the wire - neutral or ground?

L N marking in electrics is not always observed in old buildings, so the question arises of independently distinguishing between the neutral wire and the ground wire. When the circuit is closed, an electric current passes through the "zero". The grounding wire has only a protective function, and in the "normal" mode, the current does not flow through it.

You can find out whether it is “zero” or “ground” like this:

• Use an ohmmeter, having previously turned off the voltage between the measurement points. On the ground wire, the resistance will not exceed 4 ohms.
• Use a voltmeter and measure the voltage between the "phase" and other wires in series (the method is suitable for three-core cables). The ground wire will give the highest value.
• If the colors of the “phase”, “zero” and “ground” wires are unknown, and you need to find out the voltage between the ground wire and some obviously grounded object (for example, a heating radiator), a voltmeter will also come in handy. True, when connecting the "ground" and a grounded object, it will not show anything. But a small voltage will be reflected on its indicator if you do the same with the "zero" wire.

In a two-core cable, only the phase and neutral wires will always be present.

What to do if all the cores in the cable have the same color insulation

The question of marking wires by color does not make sense when you have to work with single-color cores - for example, when repairing wiring in old houses. For such cases, there are kits that make it possible to mark the cores. Areas for fixing marking devices are prescribed by the requirements of GOST, usually they are fixed next to the connection to the bus.

How to mark a wire with two cores

If all the wires in the cable have the same insulation, and the appliance is already connected to the network, the craftsmen use indicator screwdrivers. The latter glow when the metal part touches the phase wire. To mark a two-core cable, in addition to such a screwdriver, you will need thermocambrics or multi-colored electrical tape. The designation of colors will be made only at the joints - it is not necessary to wrap the core with colored tubes or electrical tape along the entire length.

Probe screwdriver-indicator

Phase wires can be marked with any color except blue, yellow and green. If a two-core cable is connected to a single-phase network, it is customary to mark the phase wire in red.

How to mark a wire with three cores

What is the color of the ground wire in a three-wire wire? If the answer to the question is not immediately determined, all the insulation on the cores of the same color will help out the multimeter. The device is set to alternating current, and the master sequentially touches both probes first with the phase wire, then with the rest of the wires, remembering the indicators. Touching phase and zero will give more voltage than touching phase and ground.

What color is the ground wire? It has a yellow-green color. It is this thermocambric or electrical tape that must be used to mark the "earth" in a three-core cable. On the “zero” - a blue tape should be wound, on the phase - not blue and not yellow-green thermocambric.

Letter designation of phase, zero and ground

The use of different colors of wires in electrical wiring is a convenient and logical measure that simplifies repair and installation work. If wires with multi-colored conductors are laid in the house, during the repair you will not have to spend time “ringing” each of them, and, for example, a break in the phase conductor will be detected quickly. The presence of a phase and zero also matters, but working with letters and numbers is still longer than with color: just look at the cable - and the purpose of the wires immediately becomes clear.

The color marking of wires is far from being an advertising "chip" of manufacturers, as some novice electricians believe. This is a special designation that allows the electrician to determine zero, ground and phase without the use of additional measuring instruments.

If the contacts are connected incorrectly, unpleasant consequences can occur in the form of a short circuit and electric shock to a person.

The main purpose of color marking is to reduce the time for connecting contacts and create a safe environment during electrical work. At the moment, in accordance with the PUE and European standards, each core has its own clearly defined color.

We will talk about the color of the neutral wire, grounding and phase.

Ground wire

By standards, the insulation of the "earth" is painted in a yellow-green hue. Some manufacturers apply yellow-green stripes to the ground conductor in the longitudinal and transverse directions. Rarely, but still found, shells are pure green or pure yellow.

On electrical circuits, "ground" is denoted by two Latin letters "PE". Grounding is often called zero protection, but this is not a working zero, not to be confused.

Neutral wire

Both in a single-phase electrical network and in a three-phase one, the neutral is painted in blue or blue. On the wiring diagram, zero is indicated by the Latin letter "N". Neutral is also called zero or neutral working contact.

phase wire

This wire, depending on the manufacturer, is marked with the following colors:

• white;
• turquoise;
• black;
• brown;
• pink;
• red;
• Violet;
• orange.

The most common phase colors are black, white and brown.

Despite its apparent simplicity, color coding has a number of features that raise the following questions for beginners:

1.What is PEN?

2. How to determine the phase, grounding and zero if the insulation has a non-standard color or is completely colorless?

Let's deal with each point.

What is PEN?

The TN-C type grounding system, which is outdated today, assumes the combination of grounding and neutral. Its main advantage is the speed of electrical work. The disadvantage of TN-C is the high probability of electric shock during wiring in an apartment or house.

The main color for designating the combined wire is yellow-green, but at the ends of the insulation there is a blue color characteristic of the neutral wire.

On the wiring diagram, such a contact is indicated by three Latin letters "PEN".

How to find phase, ground and zero?

There are cases when, when repairing a household electrical network, it turns out that all conductors have the same color. In this case, how to determine which wire is which.

In a single-phase network, where there are only two cores, without grounding, you just need to have a special indicator screwdriver with you. First you need to turn off the electricity at the switchboard. Then the wires are stripped and bred to the sides. Now we turn on the electricity again and alternately bring the indicator to each of the wires. If, upon contact, the light on the screwdriver lights up, then this is a phase, and the second core, therefore, zero.

If the electrical network is three-phase, then more sophisticated equipment is needed - a multimeter with measuring probes. First, set the device to a value above 220 volts. We fix one probe in phase, and the second we determine grounding and zero. Upon contact with zero, the tester should show a voltage of 220 volts. The ground wire will show a slightly lower voltage.

If you don’t have an indicator screwdriver or a multitester at hand, then you can determine the ownership of the wire by insulation. The important thing to know here is that the blue shell is always the neutral. Even in the most non-standard markings, its color does not change. The other two cores are more difficult to install.

The first way is based on associations. For example, you have a colored and white or black contact in front of you. Usually the earth is indicated in white or black. Therefore, the remaining wire is a phase.

The second way. We discard the neutral again. Left red and black. According to the PUE, white insulation is a phase. Then the red conductor is ground.

In circuits with direct current, the color marking of minus and plus is represented by black and red insulation, respectively. In a three-phase transformer network, each phase is painted in an individual color:

• A-yellow;
• B-green;
• S-red.

Zero, as always, is blue, and ground is yellow-green. In cables designed for a voltage of 380 volts, the wires are designated as follows:

• A-white;
• B-black;
• S-red.

The protective and neutral conductors do not differ in marking from the previous version.

We designate the wires ourselves

In the absence of a visual designation, after repair work, you must independently indicate the ownership of the wires. For this, bright electrical tape or heat shrink tubing is suitable.

According to GOST, the marking of the cores must be carried out at the ends of the conductors - at the points of their contact with the bus.

Such notes will greatly facilitate future repairs and maintenance.

Anyone who has ever dealt with wires and electrics noticed that conductors always have a different color of insulation. 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, which is probably why bright colors are chosen for them. 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 a large number of 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 marking 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.

We take a multimeter and / or an 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 the plastic handles, gently touch the metal rod of one probe to the found phase wire, the second to the supposed zero. The screen should show 220 V or the 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 again touch the phase, with the second - to the intended ground. If the meter reading is lower than the first measurement, you have the "ground" 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 - at best, to the failure of the equipment, but there may be injuries and fires.