Carrying out electrical work is a rather complicated matter, which is better to entrust to a specialist in this field. However, if it is necessary to purchase cords, wires and various cables for installation, it is necessary to understand their markings. An indication of the insulation of the alphanumeric code is the marking of the wires.
At the moment, each manufacturer indicates their products with codes so that any consumer, looking at him, can understand what the product is made of, what are the rated withstand voltage, the type of cross-section, as well as the 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. Wire marking also allows you to easily determine the location of the phase, zero, and in some cases, and grounding. Consider the main electrical products on the market.
Cables
Electric cables come in several forms depending on the purpose of use. They can also consist of copper or aluminum cores, which are bundles collected under one or different winding materials of plastic or PVC. Also sometimes there is an additional protective sheath made of steel tape.
Depending on the application, the color coding of the wires may also be different. So, they distinguish:
- Radio frequency cables transmitting radio and video signals.
- Control for signal transmission to one or another device.
- Power cables are used in lighting devices to transmit electricity. They can be used both in internal and external wiring.
- For communication, cables are used that can conduct current of different frequencies.
- In automation systems, control cables are used, which are copper conductors located under a protective shield that removes interference and prevents mechanical damage.
Wires
An article formed from several wires or from only one is called a wire. In most cases, the winding is plastic, less often wire, but also found without insulation at all.
At the moment, more 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 a winding of electric motors.
Aluminum wires have a low cost, but a huge minus is the impossibility of connecting them with others, for example, copper. Copper products can withstand loads well, but in the open air they quickly oxidize and are expensive.
Marking of electric wires also depends on their purpose. Installation and power are used both indoors and outdoors. Mounting, in turn, is used when collecting electrical circuits in switchboards or radio equipment.
Cords
The cord is a few cores with a small cross section, which consist of many intertwined wires. Most often, this electrical product is represented by stranded cords, the winding of which is non-metallic.
The main use of cords is connected to a network of industrial and household appliances.
Letter marking
Any electrical product should be marked in accordance with GOST. The first letter means the material of which the core is made. If it is copper, the letter is not assigned, if it is aluminum, then it is marked with the letter “A”.
The decoding of the marking of the cable and wire with the second letter characterizes the type or material of the insulation. It, depending on the type of wire, can be written as “P”, “M”, “MG”, “K”, “U”, which corresponds to a flat, mounting, mounting with flexible cores, control and installation type of wire. The installation may also be marked as "P" or "W".
The next, third letter means the material of the winding of the product:
- "K" - kapron;
- "C" - fiberglass;
- “BP” or “P” - polyvinyl chloride;
- "F" - metal;
- "E" - shielded;
- "P" - rubber;
- "ME" - enameled;
- "T" - a winding with a bearing torso;
- “” or “” - nayritic;
- "L" - varnished;
- "G" - a winding with a flexible core;
- “O” and “Sh” - polyamide silk as a braid or insulation.
Wire marking may also have a fourth letter, which characterizes the design features of an electrical product:
- “K” - the wire is armored with round wires;
- “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 wire - flexible, and for cable - without protection.
Digital marking
The marking of electrical wires by the first digit indicates the number of cores, if it is absent, the conductor has only one core. The second and third digit means the cross section of the wire in square millimeters and the rated withstand voltage of the network.
Grounding
For the most part, the color marking of the wires is designed to facilitate electrical work and the safety of its implementation.
According to the rule 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 grounding, wire color markings are applied either longitudinally or transversely. On electrical circuits, “ground” is usually denoted by the letters “RE”, which is also sometimes called zero protection.
Zero
The zero working contact does not carry a voltage charge, but is only a conductor. Marking of wires by color should be bluish or blue. On the wiring diagram, zero is usually denoted as "N".
Phase
The phase wire is always energized if it is connected to the network. The color marking of the phase wires can be made in many color shades - brown, black, turquoise, purple, gray and others. But most often phase conductors are white or black.
PEN conductor
In any residential building or building, grounding or grounding of electrical wiring is always necessary. Currently, it is important to carry out a TN-C grounding system, which includes the combination of grounding and neutral wires. The color marking of 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 subsequently connected to each other by a jumper in the middle or two along the edges. Then re-ground the PE bus and check the resistance.
How to determine grounding, neutral and phase?
Sometimes during repair or renewal of wiring it is necessary to determine which wire means what. But it happens that marking the wires by color is not an ally in this, because due to the long service life or in the case of a short circuit, this is impossible.
This problem can be dealt with using an indicator screwdriver, popularly called "control". This method is suitable in the case of a single-phase network, without a ground wire. First you need to turn off the power supply, separate both conductors to the sides and turn on the electrical panel again . After that, bring the indicator screwdriver to one of the wires. If the light on the "control" lights up, respectively, this wire will be the phase, and the remaining core - zero.
If the wiring is three-wire, you can use a multimeter to determine each of the wires. This appliance has two wires. First you need to install on it a rated voltage of over 220 volts. Then fix one of the wires of the multimeter on contact with the phase, and the other determine the grounding or neutral. If the ground wire is detected with the second wire, the readings on the device will drop slightly below 220, and if it is zero, then the voltage will shift to within 220 volts.
The third method for determining the wires can be used if there is no screwdriver or multimeter at hand. This can be helped by marking the wires, which in any situation will be marked in blue and blue to isolate zero. The other two contacts will be more difficult to determine.
If one of the contacts is colored and the other is white or black, then most likely the color will be a phase. According to old standards, a black-and-white color indicated a grounding conductor.
Also, according to the rules for installing electrical equipment, the land wire is marked in white.
DC marking
The marking of wires in the DC voltage network has a red color of insulation 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 ground, as usual, will be blue and yellow-green.
If a cable is inserted at 380 volts, the black, white and red insulation will correspond to the phase wires, and the color of the neutral and ground will remain unchanged, as is the case with the 220 volt network.
Self marking wires
Sometimes, in the absence of a suitable color, you can independently change the color of the same wire used for zero, phase and grounding. In this case, the decoding of the wire marking will be very useful.
You can make small notes on the wires, which in the future can be very useful. You can also use colored electrical tape and wrap the wires in accordance with the marking.
Today, cambrices, which are colored plastic tubes capable of heat shrink, are in great demand. In the case of busbars, it is also necessary to mark the ends of the conductors.