Colours coding of wires and cables in electrical wiring is not an advertising “feature” of manufacturers, as some novice electricians think, but a special event that allows an electrician to quickly find the phase, zero, and ground during installation.
If the colors are incorrectly connected to each other, this can cause such adverse consequences as electric shock and short circuit.
The main purpose of color coding is to create safe conditions for electrical work, as well as reduce the time it takes to find and connect contacts. Today, each vein has its own insulation color. About what color the wire is phase, zero, ground, we will talk further!
How to identify a grounding wire?
The insulation of the “ground” should be painted in a yellow-green hue. We draw your attention to the fact that the manufacturer also applies yellow-green stripes on the ground wire in the transverse and longitudinal direction. In some cases, the shell may be pure yellow or pure green. In the electrical diagram, grounding is usually denoted by the Latin letters “PE”. Very often, “ground” is called zero protection, it should not be confused with zero working (zero)!
How to identify a neutral wire?
Zero core (neutral) is usually blue or light blue. In the junction box, this wire is connected to the zero bus, which is marked with the Latin letter N. All blue wires are connected to this bus. It should be noted that the zero wire combines two functions: working and protective zero. The protective wire zero is also blue, and at the ends, i.e. at the joints, there are yellow-green stripes. Connects to the bus marked REN. It should be noted that generally accepted rules allow green stripes throughout the wire with blue ends.
How to identify a phase wire?
The vein responsible for the phase in the electrical wire is painted in different colors. It can be: black, brown, red, gray, purple, pink, white, orange, turquoise. Each manufacturer of electrical wires has the right to designate a phase conductor in one of these shades. Simply put, the main task of the electrician during the installation of the electrical wiring of the room is, first of all, to determine the neutral wire and the ground wire, and the remaining wire will be the phase. In order not to get an electric shock, the electrician must check the wires using a special probe, most often it is presented in the form of a screwdriver.
It’s important to know!
The color coding of wires in electrics has many features and often beginners are faced with such questions as:
- “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 standards are there for the color of the insulation?”
We will now briefly give a simple explanation to all these questions!
Both wires are the same color
So, you are faced with the following situation: during the repair of the household electrical network, it turned out that all the conductors were of the same color. How, in this case, do you know which wire means what?
If a single-phase network is presented without “ground” (2 cores), then all you need is a special indicator screwdriver. With its help, you can easily determine where is 0, and where is the phase. We talked about how to use the indicator screwdriver. First, turn off the electricity supply on the dashboard. Next, we clean the two conductors and spread them apart from each other. After that, we turn on the electricity supply and carefully determine the phase/zero using the indicator. If on contact with a core, the light bulb lights up, this is a phase, respectively, the second core is zero.
In the event that the wiring has a ground wire, equipment such as a multimeter must be used. This device has two tentacles. First, you need to set the measuring range of the alternating current to over 220 volts. Next, we fix one tentacle on the phase contact, and with the help of the second tentacle, we determine zero / ground. When in contact with 0, the multimeter will display a voltage value within 220 volts. If you touch the “ground”, the voltage will certainly be slightly lower. A more intelligible instruction for using the multimeter was provided in the corresponding article, which we recommend that you familiarize yourself with!
There is another method for determining. If you do not have a multimeter and an indicator screwdriver at hand, then you can try to determine what color the L and N wires are by their insulation. In this case, it must be remembered that the blue shell is always ZERO. In any non-standard marking, the color of the zero does not change. The other two will be a little more difficult to identify.
The first option is associations. You can see the remaining color and black or white contact. In the good old days, the earth was designated with black or white insulation. It is quite reasonable to assume that this is it, the remaining color is a phase (L).
Second option. Zero, again, immediately fold back, there remains a red and black/white wire. If the insulation is white it is a phase. So the remaining red is earth.
Please note that this method is extremely dangerous. If you decide to use it, be sure to make notes for yourself so that during the repair of the chandelier or outlet you do not get an electric shock!
I would also like to note a very important nuance – in the DC circuit, the color marking of the plus and minus is represented by black (-) and red (+) insulation colors. As for a three-phase network (for example, on transformers), here all three phases have their own individual color: phase A – yellow, B – green, C – red. Zero, as usual, is blue, and the ground is yellow-green. In a 380V cable, wire A is white, B is black, C is red. Zero working and protective conductors do not differ from the previous marking option in colors.
How to color the wires yourself?
In the event that the visual designation is absent or differs from the standard one, it is recommended to independently indicate all the elements after repair work. To do this, you can use colored electrical tape or a special product – heat shrink tubing, also called cambric. According to the requirements and generally accepted recommendations, the indication of the cores must be carried out at the ends of the conductor – at the points of its connection with the bus (as shown in the photo).
Small color marks will make repairs and maintenance easier for both you and the electrician, who may be able to repair your home power grid after you!
Existing factory standards
Insulation designations change slightly every decade, so this information may be useful to you.
Until 2000, the following wire color coding was used:
- white – N;
- black – PE;
- bright – L.
A few years after this standard, a significant change was made: PE was “repainted” in a yellow-green color (as it is now).
Thus, the products began to look like this:
- yellow-green wire – ground;
- black (and sometimes white) – neutral (N);
- bright – phase.