Color coding of wires. Decoding of cable and wire marking

Conducting electrical work is quite a complicated matter, which is better to entrust to a specialist in this field. However, if you need to purchase cords, wires and various cables for installation, you need to understand their labeling. Indication on the insulation of products of alphanumeric cipher and there is a marking of wires.

At the moment, each manufacturer designates its products with codes so that any consumer, having a look at it, could understand what the product is made of, what is the nominal withstand voltage, type of cross-section, and also features of its design and type of insulation.

To comply with these parameters, all plants and enterprises engaged in the manufacture of electrical products are required to use the international standard - GOST. The marking of the wires also makes it possible to easily determine the location of the phase, zero, and in some cases also of the earth. Let's consider the basic electrotechnical products presented in the market.

Cables

Electrical cables come in several types depending on the purpose of use. They can also consist of copper or aluminum cores, which are assembled by bundles under one or different wrapping materials of plastic or PVC. Also sometimes there is an additional protective shell of steel tape.

Depending on the application, the color coding of the wires can also be different. So, distinguish:

• Radio-frequency cables that transmit radio and video signals.
• Control signals for signal transmission to certain devices.
• Power cables are used in lighting devices for electricity transmission. Can be used in both internal and external electrical wiring.
• For the transfer of communication cables are used that can conduct a current of different frequencies.
• Automation systems use control cables, which are copper conductors located under a protective shield, which removes interference and prevents mechanical damage.

Wires

An article made up of several wires or just one of them is called a wire. In most cases, the winding is plastic, less often wire, but is also found without insulation at all.

At the moment, the preference is given to wires whose cores are made of copper or aluminum. Such products are used not only in electrical work, but also as the winding of electric motors.

Aluminum wires have a low cost, but a huge disadvantage is the impossibility of connecting them with others, for example, copper ones. Copper products can withstand loads well, but they are rapidly oxidized in the open air and are costly.

Marking of electrical wires also depends on their purpose. Installation and power are used both inside and outside the premises. Mounting, in turn, is used when collecting electrical circuits in panels or radio equipment.

Cords

The cord is a few cores with a small cross section, which consist of many interwoven wires. Most often this electrotechnical product is represented by stranded cords, the winding of which is nonmetallic.

The main use of cords is connected to the network of industrial and household appliances.

Letter marking

Any electrical product must be marked in accordance with GOST. The first letter means the material from which the vein is made. If it is copper, the letter is not assigned, if aluminum, it is marked with the letter "A".

The decoding of the cable and wire marking with the second letter characterizes the type or material of insulation. Depending on the type of wire, it can be written as "P", "M", "MH", "K", "U", which corresponds to flat, mounting, mounting with flexible wires, control and installation type of wire. The installation can also be labeled as "P" or "W".

The next, third letter, means the material of the winding of the product:

• "K" - nylon;
• "C" - fiberglass;
• "BP" or "P" is polyvinyl chloride;
• "F" - metal;
• "E" - screened;
• "Р" - rubber;
• "ME" - enameled;
• "T" - winding with a bearing torso;
• "HP" or "H" is a nai- rithic;
• "L" - varnished;
• "G" - winding with a flexible core;
• "O" and "SH" - polyamide silk as a braid or insulation.

The marking of wires can also have a fourth letter that characterizes the structural features of an electrical product:

• "K" - the wire is armored with round wire;
• "A" - asphalt wire;
• "T" - the product is used for conducting in pipes;
• "B" - armored with ribbons;
• "O" - the presence of a protective braid;
• "G" - for the wire - flexible, and for the cable - without protection.

Digital Marking

The marking of electric wires according to the first digit indicates the number of cores, in case it is absent, the conductor has only one core. The second and third digit denote the wire cross section in millimeters square and the rated stand-by voltage of the network.

Earthing

Most of the color marking of the wires is designed to facilitate the conduct of electrical work and the safety of its implementation.

According to the rule of the device of electrical installations, the insulation of the ground conductor must have a green-yellow color. In some cases, the color may be exclusively green or only yellow.

For earthing, the color of the wires is applied either in the longitudinal direction or in the transverse direction. On electrical circuits "ground" is usually denoted by the letters "PE", which is also sometimes called zero protection.

Zero

The zero working contact does not carry a charge of voltage, but is only a conductor. Marking the wires according to the color should be bluish or blue. On the electrical circuit, zero is usually referred to as "N".

Phase

The phase wire is always energized if it is connected to the mains. The color identification of the phase wires can be made in many color shades - brown, black, turquoise, violet, gray and others. But most often the phase conductors are white or black.

PEN-conductor

In any residential building or building, it is always necessary to ground or neutralize the wiring. Currently, it is important to conduct a TN-C grounding system, which includes the interconnection of grounding and neutral wires. The marking of the color of the wires combined in such a system will change from yellow-green to blue.

First, you need to divide the conductor into two buses - PE and N, which are then connected together by a bridge in the middle or two along the edges. Then re-ground the PE bus and check the resistance.

How to determine the ground, neutral and phase?

Sometimes during repair or renovation of the wiring it is necessary to determine which wire that means. But it happens that the color coding of the wires in this is not an ally, because because of the long service life or in the case of a short circuit it is impossible.

This task can be handled using an indicator screwdriver, popularly called "control". This method is suitable for a single-phase network, without a ground wire. First you need to turn off the electricity supply, dilute both conductors to the sides and turn on the electrical shield again . After that, bring the indicator screwdriver to one of the wires. If the lamp on the "control" is lit, respectively, this wire will be the phase, and the remaining wire is zero.

If the wiring is three-wire, you can use a multimeter to determine each wire. This device has two wires. To begin with, it is necessary to install a rated voltage above 220 volts on it. Then one of the wires of the multimeter should be fixed on the contact with the phase, and the other to determine the ground or neutral. If the second wire detects an earth conductor, the readings on the instrument will drop a little below 220, and if zero, the voltage will shift to 220 volts.

The third method of determining the wires can be used if there was not a screwdriver or a multimeter at hand. This can help marking the wires, which in any situation for the isolation of zero will be marked in a blue-blue color scheme. The other two contacts will be more difficult to determine.

If one of the contacts is colored, and the other one is white or black, then, most likely, the color phase will be. According to the old standards, black and white color denoted a grounding conductor.

Also, according to the rules for the installation of electrical equipment, white color marks the ground wire.

Marking in a chain of a direct current

The marking of the wires in the DC network has a red insulator for plus, and black for minus. If the network is three-phase, then each phase will have its own specific color: red, yellow and green. Zero and grounding, as usual, will be blue and yellow-green.

If a 380-volt cable is inserted , the wires of the phases will be matched with black, white and red insulation, and the color of the neutral and earth will remain unchanged, as in the case of a 220-volt network.

Independent designation of wires

Sometimes, in the absence of a suitable color, you can change the color of the same wire used for zero, phase and ground. In this case, decoding the marking of the wires will be very handy.

You can make small notes on the wires, which in the future can be very useful. You can also use colored electrical tape and wind wires according to the marking.

To date, great demand for cambric tubes, which are colored plastic tubes, capable of heat shrinkage. In the case of using tires, it is also necessary to mark at the ends of the conductors.