When working with electricity, you can see that the strands of wires are painted in different colors. Interestingly, the colors never repeat, regardless of the number of conductors in one sheath. Why this is done and how not to get confused in the color variety - this is our today's article.
The essence of the color marking of wires
Working with electricity is a serious matter, as there is a risk of electric shock. It is not so easy for a simple person to cope with, because by cutting the cable, you can see that all the cores have a different color. This approach is not an invention of manufacturers in order to distinguish their products from competitors, but is very important when installing electrical wiring. To avoid confusion with the color of the cable cores, all the variety of colors is reduced to one standard - PUE. The electrical installation rules state that wire cores must be differentiated by color or alphanumeric designation.
Color marking allows you to determine the purpose of each wire, which is extremely important when switching. The correct connection of the cores to each other, as well as during the installation of electrical installation products, helps to avoid serious consequences, such as a short circuit, electric shock, or even a fire. Properly connected wires help to subsequently carry out repairs and maintenance without problems.
According to the rules, the color of the wires is present along the entire length. However, in reality, you can find electrical wires painted in one color. Most often this is found in the old housing stock, where aluminum wiring is laid. To solve problems with the color designation of each individual core, a heat-shrinkable tube or electrical tape of different colors is used: black, blue, yellow, brown, red, etc. Multi-colored marking is done at the junction points of the wires and at the ends of the cores.
Before talking about the color difference, it is worth mentioning the designation of wires with letters and numbers. A phase conductor in a single-phase AC network is indicated by the Latin letter "L" (Line). In a three-phase circuit, phases 1, 2 and 3 will be respectively designated "L1", "L2", "L3". The grounding phase conductor is designated by the abbreviation "LE" in a single-phase network and "LE1", "LE2", "LE3" in a three-phase network. The neutral wire is assigned the letter "N" (Neutral). The neutral or protective conductor is designated "PE" (Protect Earth).
Ground wire color code
According to the rules for the use of electrical equipment, all of it must be connected to a network that has a ground wire. It is in this situation that the manufacturer's warranty will apply to the equipment. According to the PUE, the protection is in a yellow-green shell, and the color stripes must be strictly vertical. In a different location, such products are considered non-standard. Often you can find cores with a sheath of bright yellow or green color in the cable. In this case, they are used as grounding.
Interesting! A hard single-core ground wire is colored green with a thin yellow stripe, but in a soft stranded one, on the contrary, yellow is used as the main one, and green acts as an additional one.
In some countries, it is allowed to install a ground conductor without a sheath, but if you come across a green-yellow cable with a blue braid and the PEN designation, then you have ground combined with neutral. You should be aware that the earth is never connected to the residual current devices located in the switchboard. The ground wire is connected to the ground bus, to the housing or the metal door of the switchboard.
On the diagrams, you can see a different designation of grounding, so to avoid confusion, we recommend that you use the following memo:
A separate color for the neutral wire and a variety of colors for the phase
As evidenced by the PUE, for the neutral wire, which is often called zero, a single color designation is allocated. This color is blue, and it can be bright or dark and even blue - it all depends on the manufacturer. Even on color schemes, this wire is always drawn in blue. In the switchboard, the neutral is connected to the neutral bus, which is connected to the meter directly, and not using the machine.
According to GOST, the colors of the phase wires can have any color except for blue, yellow and green, since these colors refer to zero and ground. This approach helps to distinguish the phase wire from the rest, since it is the most dangerous at work. Current flows through it, so it is extremely important to provide the correct designation in order to work safely. Most often, phase cores in a three-core cable are indicated in black or red. The PUE does not prohibit the use of other colors, with the exception of colors intended for zero and earth, therefore, sometimes you can find a phase core in the following shells:
- brown;
- gray;
- purple;
- pink;
- white;
- orange;
- turquoise.
If the colors are mixed up
We have given the basic rules for marking L, N, PE lived in an electrician by color, but it often happens that not all craftsmen follow the rules for installing electrical wiring. Among other things, there is a possibility that the electrical wires with a different color of the phase core or even a single-color cable have changed. How not to make a mistake in such a situation and make the correct designation of zero, phase and ground? The best option in this case would be marking the wires according to their purpose. It is necessary with the help of cambric (heat shrink tubes) to designate all the elements that depart from the switchboard and follow into the dwelling. The work may take a long time, but it's worth it.
To work on identifying the ownership of the cores, an indicator screwdriver is used - this is the simplest tool, which is elementary to use for subsequent marking of the phases. We take the device and with its metal tip we touch the bare (!) Core. The indicator on the screwdriver will only light up if you have found a phase wire. If the cable is two-core, then there should be no more questions, because the second conductor is zero.
Important! Any electrical cable always has L and N cores, regardless of the number of wires inside.
If a three-wire wire is being examined, a multimeter is used to find the ground and neutral wires. As you know, the presence of electricity is possible in the neutral conductor, but its doses will hardly exceed 30V. To measure on the multimeter, you must set the AC voltage measurement mode. After that, with one probe they touch the phase conductor, which was determined with the help of an indicator screwdriver, and with the second - to the remaining ones. The conductor that showed the lowest value on the device will be zero.
If it turned out that the voltage in the remaining wires is the same, you must use the resistance measurement method, which will determine the ground. For work, only cores will be used, the purpose of which is unknown - the phase wire is not involved in the test. The multimeter is switched to the resistance measurement mode, after which one probe touches a deliberately grounded and cleaned to metal element (this can be, for example, a heating battery), and the second probe touches the wires. Ground should not exceed 4 ohms while neutral will be higher.