Wire color coding
If you incorrectly connect the contacts to each other in color, this can cause adverse effects such as electric shock and short circuit.
The main purpose of color marking is to create safe conditions for electrical work, as well as reducing the time for searching and connecting contacts. Today, according to the PUE and existing European standards, each core has its own isolation color. About what color the wire phase, zero, earth, we will talk further!
What does grounding look like?
According to the PUE, the insulation of the "earth" should be painted in a yellow-green shade. We draw your attention to the fact that the manufacturer also applies the application of yellow-green stripes to the ground wire in the transverse and longitudinal directions. In some cases, the shell may be pure yellow or pure green. On the electrical circuit, grounding is usually denoted by Latin letters "PE". Very often, “land” is called zero protection, do not confuse it with zero working (zero)!
What does neutral look like?
In three-phase and single-phase mains, the color of zero should be blue or blue. On the electrical circuit, "0" is usually denoted by the Latin letter "N". Zero is also called a neutral or zero working contact!
What does the phase look like?
The marking of the phase wire (L) by the manufacturer can be carried out in one of these colors:
- the black;
Most often, the color of the phase wire is brown, black and white.
It's important to know!
The color marking of wires in an electrician has many features and often beginners come across issues such as:
- "What is the abbreviation PEN?";
- “How to find grounding, phase, zero, if the insulation is colorless or has a non-standard color?”;
- "How to independently indicate the phase, grounding, zero?";
- “What other insulation standards exist?”
We will briefly give a simple explanation for all these questions!
What is a PEN?
The outdated TN-C grounding system today involves the use of a combination of neutral and grounding. The advantage of such a system is the ease of electrical work. The disadvantage is the risk of electric shock when installation of electrical wiring in the house or apartment.
The color of the combined wire is yellow-green (like PE), but at the same time the insulation at the ends has a blue color, characteristic of neutral.On the electrical diagram, the combined contact is indicated by three Latin letters - "PEN".
How to find L, N, PE?
So, you are faced with this situation: during the repair of the household electrical network, it turned out that all the conductors are the same color. How in this case to find out which wire means what?
If a single-phase network is presented without a “ground” (2 cores), then all you need is a special indicator screwdriver. With its help, you can easily determine where 0 and where phase. About, how to use an indicator screwdriver we told. First, turn off the electricity on the shield. Next, we clean the two conductors and separate them from each other. After that, turn on the electricity supply and carefully determine the phase / zero using the indicator. If a light comes on when it comes into contact with a wire, this is a phase, so the second wire is zero.
In the event that the wiring has a grounding wire, you must use equipment such as a multimeter. This device has two tentacles. First you need to set the AC current measurement range to over 220 volts. Next, we fix one tentacle on the phase contact, and using the second tentacle we determine zero / ground. In contact with 0, the multimeter displays a voltage value within 220 volts. If you touch the "earth" - the voltage will certainly be slightly lower. More intelligiblemultimeter instructions was provided in the corresponding article, which we recommend that you read!
There is another method of determination. If there is no multimeter and indicator screwdriver at hand, then you can try to determine what color the wires L and N are by their insulation. In this case, you must remember that the blue shell is always ZERO. In any non-standard marking, the color of zero does not change. The other two cores will be a little more difficult to determine.
The first version of the associations. You see the remaining color, black or white contact. In the good old days, the earth was designated black or white insulation. It is quite reasonable to assume that it is she, the remaining color - phase (L).
The second option. Zero, again, immediately fold back, there is a red and black / white wire. If the insulation is white, then according to the PUE it is a phase. So the remaining red is the earth.
We draw your attention to the fact that such a method is extremely dangerous. If you decide to use it, be sure to make notes for yourself so that during chandelier repair or sockets do not get an electric shock!
I would also like to note a very important nuance - in a direct current circuit color marking of plus and minus is represented by black (-) and red (+) insulation color. As for the three-phase network (for example, on transformers), here all three phases have their own individual colors: phase A - yellow, B - green, C - red. Zero, as usual, is blue, and grounding is yellow-green. In the 380 V cable, wire A is white, B is black, C is red. Zero working and protective conductors do not differ from the previous color marking option.
How to specify L, N, PE independently?
In the event that the visual designation is missing or differs from the standard, it is recommended to independently indicate all the elements after repair work. To do this, you can use colored tape or a special product - a heat shrink tube, also called cambric. According to the requirements of the PUE, GOST and generally accepted recommendations, the wires must be indicated at the ends of the conductor - at the places of its connection with the bus (as shown in the photo).
Small color marks will facilitate the repair and maintenance of both you and the electrician, who will be able to carry out repairs of the home electrical network after you! About, how to mark wires in the shield, we told in a separate article.
Existing Factory Standards
The designations of insulation change slightly with each decade, so this information may be useful to you.
Until the year 2000, the following color coding of wires was used:
- white - N;
- black - PE;
- bright - L.
A few years after this standard, a significant change was made: PE was “repainted” in yellow-green (as it is now).
Thus, the products began to look like this:
- yellow-green wire - ground;
- black (and sometimes white) - neutral (N);
- bright is the phase.
If for some reason you get confused between the contacts, we offer you a detailed decoding of the marking of wires and cables by colors, which today complies with European and domestic standards:
Finally, we recommend watching a useful video on the topic: