Marking of wires and cables in color

Forthe correct connection of electrical panels it is important to follow certain rules. The main document for any electrician who is engaged in the installation of electrical wiring is the EMP "Rules for the installation of electrical installations."It describes how to correctly perform wiring, how to calculate the cross-section of wires, what cable or wire to use.

In addition to PUE it is necessary to know GOST R 50462-2009.The document describes in detail which color and letter symbols can be used for various wires and cables. This document came into force only in 2011.

This is a new standard, which is very different from the previous one. The fact that the color marking of wires in the new GOST in many respects contradicts the requirements of the PUE.The new GOST is developed according to European standards, which differ from domestic ones. This often leads to confusion when installing electrical equipment.

Labeling of wires according to purpose and color

Marking of wires and cables, which is applied by the manufacturer, refers to the factory marking. This is the color of the shell and the letters.

Colored and alphabetic designations allow you to get all the information you need. Where, and in what capacity it is necessary to use this wire.

The color carries information about the purpose of the wire. In most cases, the color marking is applied over the entire length of the wire. If the wire is not insulated, the marking is applied at the joints and at its ends.

In accordance with existing standards, the following colors of wires are allowed:

- black;

- white;

- blue;

- pink;

- purple;

- orange;

- brown;

- red;

- yellow-green;

- the turquoise.

- gray;

Knowledge of color and letter designations greatly shortens the time of installation works, allows eliminating errors when connecting wires. Errors can lead to a short circuit and personnel injury by electric current during commissioning.

Protective conductors.

Yellow and green are used for the marking of protective conductors. They can be applied along or across the conductor. And in GOST even the ratio of colors relative to each other is determined. From 30 to 70 percent of the wire surface is the same color, the rest of the surface of the other( for every 15mm length).In the old standard, these requirements were not mentioned.

The new GOST shall not be used separately for green and yellow colors!

If a non-insulated wire of a different color is used as the protective conductor, it must be identified with a sticky yellow-green tape.

Alphanumeric designation - PE.

Zero conductor

When marking the neutral conductor of AC circuits, blue is used. It is often called "neutral".The letter designation is N. In no case should one confuse the "land" with the worker "0".

PEN or TN-C system

This is a grounding system in which the protective conductor and the "0" working along the entire length are combined. They have a yellow-green marking. The junction points and the ends of the wire are blue. Reverse marking is also allowed: along the entire length - blue, at the ends and at the junctions - yellow-green.

The TN-C system used to be ubiquitous. Simplicity of installation stood in the first place. Now the safety of people has come first. The four-wire system is increasingly being replaced by a five-wire TN-S system. In it, the "zero" and "protective" wires are separated.

In some projects the division into PE and N is performed at substations. The consumer is supplied with a five-wire cable to the consumer. But most often the separation takes place in the central cabinets with an introductory machine( or disconnector).

Phase conductors

The color marking of phase conductors in a three-phase circuit is gray, brown and black. If the chains have a more complex configuration, marking with other colors permitted by GOST is used.

Conventional letter designation of the phase conductor is L. For the three-phase circuit, the designations L1, L2, L3 are used. For direct current circuits, the designation "L +" and "L-".

Marking of wires according to GOST R 50462-2009

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The table shows the main types of conductors with marking.

Technical characteristics marking

Cables and wires are marked not only for their intended purpose. The cable sheath is usually indicated by an alphanumeric designation, by which its technical characteristics can be determined.

Lettering of domestic products:

1 - core material( A - aluminum);

2 - a kind of wire( M - mounting, K - control, etc.);

3 - insulation material( P - rubber, P - polyethylene, etc.);

4 - protective construction( B - armored with metal strips, T - for laying in pipes, etc.).

Numerical designation of domestic products:

1 - number of cores( there is no first digit on single-wire wire);

2 - section;

3 - the maximum voltage.

Designations according to the European standards:

N - VDE standard;

Y - PVC insulation;

M - mounting cable;

RG - armored protection;

C - shielded cable;

SL - control cable;

05 - voltage up to 500 V;

07 - voltage up to 750 V.

This is the most common and well-known marking of cable products.

Marking of cable endings

In industrial production, in telephone, telecommunication networks use one more kind of marking - marking of cable lugs.

When using cables with a large number of cores, marking is applied when connecting to junction boxes, shields, connectors. Otherwise, it will be impossible to find the desired core. This is especially important when assembling electrical panels.

The marking of cable ends can be applied in various ways:

• with an indelible marker( cheap, but not long-lasting);
• using a self-laminating marker;
• using marking elements( not suitable for all cable types);
• using marking equipment( used by professional installation organizations).

Introduction of new GOST designation of wires pros and cons

The introduction of new European standards greatly simplified the installation of new, modern equipment. But, at the same time, a number of problems arose in the maintenance of old electrical installations, mounted even according to the old rules. It is not possible to replace the wiring in all old electrical installations. The new GOST does not require this. It is especially difficult for electricians with experience to adapt to new rules.

Earlier, the phase wires could be yellow, green and red. Now yellow and green are used only for grounding conductors. In existing installations, the black potential equalization bus. Now this color is used only for marking the phase conductor. Problems in determining the appointment of a conductor can lead to an accident. In order to avoid problems, it is of prime importance to give the alphanumeric marking and arrangement of tires. It is also necessary to closely monitor changes in regulatory documents.

Definition of conductors without marking at home

In ordinary life, one often has to deal with a situation where there is no marking of the household electricity network at all. All the conductors in the shield can be the same color.

In all old houses the network is two-wire, i.e.without a protective conductor. Determine what "zero", which is the "phase" can be an indicator screwdriver. This tool can be found in every home. When contacting the neutral conductor, the light on the indicator screwdriver does not light. When touched in the phase conductor - lights up.

If there is a ground wire in the network, a multimeter is required. With its help you can determine the type of wire - earth or zero. It is necessary to set the value of voltage over 220 V. One contact is connected to the phase conductor. The second one in turn is applied to the remaining two wires. The neutral wire will show the value of 220 V, the earth wire will be below this value.

The main thing in carrying out any work related to electricity, observe utmost care and caution.