When we take a look at the cables that make up an electrical installation, one of the things that attracts our attention is its wide variety of colours. Have you ever wondered why? Although at first glance it may seem a purely aesthetic issue, each colour actually tells us something about the cable. If you want to know what the colours of the electric cables mean, we recommend you continue reading, because we will give you all the details.
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Before summarizing what the colors of the electric cables mean, it is worth remembering what the parts of a cable are.
- Isolation. It is the coating that wraps the electrical conductor to prevent the electric current from circulating outside it and harm the person who is handling the cable. It also prevents cables from coming into contact with others and can cause a short circuit. The insulations can be made of plastic or elastomeric materials, or paper impregnated with viscous or fluid oil.
- Driver. It is the element that channels or conducts electricity. While it may be made of various materials, copper is the most common. Aluminum is also used, since, although its conductivity is lower, it is lighter. A driver can have a single filament or several.
- Fill layer. It is an insulating material which wraps electrical conductors to maintain the circular section of the whole assembly.
- Cover. It is made of materials that protect the cable mechanically and serves to protect the insulation of electrical conductors from sun, rain or temperature changes. Therefore, it is the outermost part of the cable.
Before handling electrical cables, it is prudent to know about the color code of the cables, which will help us handle them correctly and with less irrigation. As you know, there are cables of various shades, the most common being the following: yellow, blue, white, gray, brown, orange, black, red, green and violet, each of which performs a certain function. So that you know what each one corresponds to, we will summarize the color code of the different cables and electrical standards. Such information that must be clear before intervening in any installation.
The colors of the electric cables and their functions have been in force in their current forms since 1970. To know what they mean, we must refer to IEC 60446, a standard of the International Electrotechnical Commission that indicates the values or labels to identify each cable according to its color, and that is the one used mostly throughout Europe.
That said, it should be remembered that there are three types of cable: the phase, the neutral and the earth, which has no current and is only a protection element, in case current is derived from an appliance to its housing due to bad contact. In turn, the neutral cable serves to create a potential difference – the potential difference between the phase and neutral cables in Western Europe is about 220 V -, which allows the existence of electric current through the phase conductor . Thus, the neutral causes the current to be grounded through that cable, and not through the body of the person who is handling the wiring. To distinguish the phase wire from the neutral, a pole finder is used.
Now that we know what types of cable exist, let’s see how to identify each one from its color.
Years ago, the most common colors to identify the phase cable were brown or black. However, at present, the current regulations establish that, in single-phase installations – that is, with a single phase and a power of up to 10 kW -, brown, labeled L. should be used. Likewise, brown is also used to identify the first phase (L1) of a three-phase installation – that is, a system of production, distribution and consumption of electrical energy formed by three single-phase alternating currents of identical frequency and amplitude – the second and third color being black (L2) and gray (L3). Therefore, it is not uncommon to find gray wiring to signal the phase in a domestic installation.
Exceptionally, one of the three phases of three-phase installations may have a higher voltage than the rest, which is known as long leg or high leg connections. In this case, this can be indicated with an orange wire, which will be the highest voltage wire.
On the other hand, you should bare in mind that you may run into old installations in which other colours of phase cables have been used: for example, red, in single-phase installations, or a combination of red, yellow and blue for three phase installations.
Returning to IEC 60446, this regulation maintains blue as the color stipulated by previous versions of the standard. Its label is N. In some older installations, it is not uncommon to find black or white wires, which is especially common in America.
The ground wire is usually green-yellow. In most cases, it is a green wire with a yellow line. These drivers are not branded. In some cases, the ground wire may be violet.
If you have doubts despite the details we have mentioned, do not hesitate to use a connected multimeter such as an AC voltmeter to test the electrical wires.