What do the colors of wire insulation mean - according to PUE and in real life

  • Dec 14, 2020

It is very difficult to understand the wiring, especially if you are visiting the facility for the first time. It is even more difficult to do this when electricians ignore such a regulatory document as PUE and determine the purpose of the wires on their own. To prevent this from happening, you just need to look at a specific section.

What document regulates the color of the wire

The main regulatory document of both the power engineer and the regular electrician is the device rules electrical installations, which clearly and clearly describes the processes of electrical installation, as well as its subtleties and nuances.

In clause 2.1.31. indicated that:

  • The zero working conductor should be blue, the ground should be yellow-green, and the phase should be black, brown, red, purple, gray, pink, white, orange or turquoise.
Figure 1: Working "zero"
  • The neutral protective conductor (often used as an unintended earth conductor) is yellow-green in color and is marked with blue marks at the ends of the wire.
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Figure 2: Red is the most popular phase color
  • The purpose of any conductor of the network should be easily determined along its entire length, and not only at certain points, for example, when connected in an electrical room.
Figure 3: Yellow-green - ground color

But there is also an earlier point, namely - 1.1.29, in which all the values ​​of the color indication are repeated, and its main difference from 2.1.31. in the marking of the neutral protective conductor. Here, the opposite is true - blue along the entire length, and at the ends of the mark is yellow-green.

You should also pay attention to GOST 50462, where the wires are not only assigned the corresponding colors, but also digital values.

How marking is used in everyday wiring

In order not to learn the marking according to regulatory documents, it is best to remember a simple rule: the phase is indicated by any “aggressive” color, and “zero” - neutral. Aggressive colors include red, black, dark brown, which are so defined even at a subconscious level. Blue or blue colors do not carry any danger or threat, they are neutral.

In cars, everything is arranged a little differently. The blue color can mean the same "+", which, if screwed to the case, in the safest case will damage the fuse, and in the most unpleasant case, it will cause a fire in the wiring.

How to protect yourself?

If by chance all the colors of the insulation flew out of your head or you want to make sure that the wire is safe, even if it is the accepted blue color, then the best option would be to use an indicator screwdriver.

Even the most inexpensive indicator screwdriver will accurately show the phase wire in 98 cases out of 100. This is evidenced by a special lamp built into the body of the device. It is enough to touch the screwdriver from the opposite side with your finger, and with the sting of the product, touch the current-carrying end of the core.

Indicator screwdrivers are absolutely safe, inexpensive, take up little space, but are an invaluable assistant in electrical installation.