Determining the belonging of the wires (phase, zero, ground) using color identification (the color of the insulation of the conductors) greatly simplifies and speeds up the process of installing switchboards and electrical wiring. But you should immediately make a reservation that you cannot rely only on when determining the ownership of the wire.

Color marking of wires according to GOST

By GOST conductors are marked with insulation color according to the table:

Colors used to designate phase conductors of electrical wiring

But, instead of trying to memorize all the standards, in order to be able to independently perform electrical work efficiently and safely, you need to learn a few mandatory rules:

Most often, phase wires are made with red, brown and black insulation. When installing phases with the same wires of the allowed color, be sure to put colored tubes or coils of colored electrical tape at their end.

In DC circuits, plus is indicated in red, minus in black. Sometimes minus is indicated in blue, but in systems with bipolar power (plus, minus, zero), the zero wire must be blue.

Insufficiency of GOST standards when installing complex circuits

The inaccuracy of the human eye in the correct determination of color shades makes it impossible to reliably decipher the color marking of many wires that differ in their function in complex electrical circuits.

If equipment is assembled in which there are AC and DC circuits, as well as various signal wires, then in addition to GOST, it is stipulated in the terms of reference and other regulatory documents, and is indicated in the wiring diagrams.

Assembling a complex control panel

In addition to color marking, in complex equipment there must be an alphanumeric identification of each wire using tags or PVC (cambric) tubes, heat shrink tubes, dressed at the end of the conductors.

It will not be superfluous to apply this practice when assembling a home electrical panel - that is, to sign the functional affiliation of each wire with conditional abbreviations on tags, tubes or the insulation itself.

Special tags

Causes of possible incorrect color identification

When repairing or upgrading a switchboard, one cannot rely only on the color of the wires, determining their ownership. After all, according to the old GOST, the phases were determined in red, green, yellow, zero - in blue, and grounding - in black.

According to the new standards of GOST and PUE of the seventh edition, grounding is determined by yellow-green color, and the phase wire can be black. The discrepancy between old and new GOST standards can lead to confusion, installation errors and even accidents.

Many electricians of the old school, not wanting to learn the new GOST, or simply following the traditions, continue to install electrical wiring the old fashioned way, thereby exposing younger colleagues to danger.

Installation was done "somehow" without observing color identification

It must be borne in mind that color coding wires and cables cannot always be done according to the rules due to the incompetence of an electrician, the lack of wires of the right color, a manufacturer's defect or an installer's mistake.

In addition, countries from different regions of the world have their own decoding color marking of power and signal wires of alternating and direct current. Therefore, when connecting various products, you should always check the diagram and instructions, not relying only on color coding.

Color identification of wires in different countries of the world

Therefore, given the above arguments, you can rely on the color marking of wires only if the following conditions are met:

In all other cases, experienced professional electricians strongly recommend determining the phase, zero and ground using instruments and visual control of the wires.

Determining the purpose of the wires in the shield and wiring

You can determine the phase in a single-phase shield using a tester, multimeter, indicator, probe in the form of a light bulb. You can determine the belonging of each phase (A, B, C, or L1, L2, L3) by performing phasing using a phase meter.

Digital phase meter for phase detection

Guaranteed determination of zero (in systems with a solidly grounded neutral) is ensured by the absence of voltage on the wire and the presence of almost zero resistance between this conductor and the ground bus.

Carrying out measurements in the shield

Protective conductor PE(grounding), in the absence of color identification in the socket or junction box, you can determine by first turning off the zero in the shield, connecting a light bulb between the phase and the wire under test.

Homemade measuring device electrician - "control"

If it is set in the panel, it will turn off immediately. If the RCD is not installed, then the 220 V lamp should be lit. If the glow is dim, then the grounding is of poor quality, respectively, unreliable.

The culture of wiring

It is important not only to know the decoding of color identification, but also to consistently observe this marking when branching lines and their passage through various devices - circuit breakers, RCDs, contactors, etc.

The execution of each power line along its entire length in one unique color indicates a high culture of wiring. Assembled in this way electrical panel will not only look aesthetically pleasing, but will also allow you to determine the passage of power circuits at a glance.

High culture of electrical installation

Unfortunately, it is not always possible to purchase cable products with the required color of the current-carrying cores. For example, in a five-wire cable, the phase conductors may be marked red, yellow, and green.

Moreover, a cable with single-color cores may be available. In this case, it is imperative to perform, followed by marking the endings.

Special markers for cable endings

If the input to the shield is carried out with a cable with a non-standard coloring, then the ends of the conductors must be marked with the corresponding colors, and the power lines should be continued according to the selected identification.

Possible errors when deciphering color markings

The non-standard color of the wires, the invisibility or fading of colored endings on the same-color cable cores can lead to incorrect interpretation of color identification. Therefore, it is necessary to choose a cable with clearly distinguishable colors, and it is better that the coloring be carried out along the entire length of the cable strands.

When working with such a cable, it is easy to make a mistake.

Sometimes cable manufacturers paint the insulation of current-carrying cores only from the ends of the cable. If the cable is cut into shorter lengths, separate cores are needed.

Occasionally, several conductors in a cable may be insulated with the same color. Very rarely, but a factory marriage happens, and the ends of the conductors are marked incorrectly.

Single color cable

To be sure to avoid trouble, you must definitely develop the habit of checking the cable used during installation - in addition to errors with coloring, there may be a wire break or a short circuit.