Often the concepts of cable and wire are used as synonyms, and only experts who are knowledgeable in electricity clearly understand that these products are different. Each of them has different technical characteristics, scope and design. In some cases, only one of them can be used. To understand how a cable differs from a wire, it is necessary to consider both products in terms of their structure and purpose.
Content
What is a cable?
A cable is a product in which there are 1 or more insulated conductors. They can be covered with armor protection if the scope of application implies the possibility of mechanical damage.
According to the areas of use, cables can be:
- Power. They are used for the transmission and distribution of electricity by means of lighting and power plants through cable lines.They can have aluminum or copper conductors with a braid of polyethylene, paper, PVC and rubber. Equipped with protective covers.
- control. They are used to power equipment with low voltage and create control lines. The main material for the manufacture of cores with a cross section of 0.75-10 mm² is copper and aluminum.
- Managers. Designed for automatic systems. Manufactured from copper with a plastic sheath. Equipped with a protective shield against damage and electromagnetic interference.
- For transmission high frequency (long distance) and low frequency (local) communication signals.
- RF. Thanks to them, communication between radio engineering devices is carried out. The product consists of a central copper core and an outer conductor. The insulating layer is made of PVC or polyethylene.
What is a wire?
The wire - this is a product of 1 bare or several insulated conductors. Depending on the laying conditions, the braid can be made of fibrous materials or wire. Distinguish naked (without coatings) and isolated (with rubber or plastic insulation) products.
The material of the cores in the wires can be aluminum, copper and other metals. It is recommended to install electrical wiring from 1 material.
Aluminum wiring is lighter in weight and cheaper, it also has high anti-corrosion properties. Copper conducts electricity better. The disadvantage of aluminum is a high degree of oxidation in air, which leads to the destruction of joints, a drop in voltage and a strong heating of the docking point.
Wires are protected and unprotected.In the first case, in addition to electrical insulation, the product is covered with an additional shell. The unprotected do not have one.
According to the scope of application, the wires are classified into:
- Mounting. Used for flexible or fixed mounting in electrical panels. In addition, in the manufacture of radio and electronic devices.
- Power. Used for laying networks.
- Installation. With their help, the installation of the connection of installations, power transmission systems indoors and outdoors is carried out.
There is a separate category of wires - cords. They are designed to create a mobile connection. Wires differ from the cord in the density of core insulation, large cross section and power.
What is the difference between cable and wire?
The main difference between a cable and a wire is its purpose. Cables are used to transmit electric current over long distances between houses, cities, or laying inside a building. They have additional protective layers for this. The wire is usually needed for internal installation indoors or internal installation in electrical cabinets.
Insulation
Since the cable can be laid in various, including aggressive environments, the cable insulation must be designed for this. For strength, additional armor is added - a metal braid, each core, except for insulation, can be covered with an additional film, and the space between the cores is filled with an absorbent (talc) - to absorb moisture and worsen combustion.
The wire does not need all this, it has one layer of PVC insulation.
Marking
All electrical products are labeled, which describes in detail their characteristics and purpose. The inscriptions on cables and wires have their own differences.
The wire marking is deciphered as follows:
- The presence of the letter "A" in the first place indicates that the conductor is aluminum. If the first is not "A" - copper.
- The letter "P" indicates the presence of 1 wire, "PP" - 2 or 3 flat conductors.
- The next letter tells about the core insulation material: “P” - polyethylene, “R” - rubber, “V” - polyvinyl chloride, “L” - cotton yarn braid.
- If after the designation of the shell follows "H", this indicates an additional protective layer of non-combustible nayrite, "B" - PVC.
- If there is a flexible current-carrying core in the wire, it is denoted by the letter "G".
- Stranded products with an anti-rotten coating are marked "TO".
- The numbers in the code indicate the type of polyethylene and the cross section of the conductor.
When marking cables, GOST established the following procedure:
- Core material ("A" - aluminum, the absence of a letter - copper).
- Type ("K" - control, "KG" - flexible).
- Insulation ("P" - polyethylene, "V" - polyvinyl chloride, "R" - rubber, "NG" - non-combustible, "F" - fluoroplastic).
- Armor or outer shell ("A" - aluminum, "C" - lead, "P" - polyethylene, "B" - polyvinyl chloride, "P" - rubber, "O" - coating of all phases, "Pv" - polyethylene vulcanized).
- Protective layer ("B" - armor with anti-corrosion coating, "Bn" - non-combustible armor, "2g" - double polymer tape, "Shv" - polyvinyl chloride hose, "Shp" - polyethylene hose, "Shps" - self-extinguishing polyethylene hose) .
In addition to these designations, there are many others that indicate special characteristics.For example, the letter "E" at the beginning of the code indicates that the cable is electric. The same letter in the middle indicates the presence of a screen.
Immediately after the letter designation, a digital one follows, in which the first number indicates the number of cores, the second - their cross section.
The voltage index “W” must be indicated on the cables. The number behind it is deciphered as follows: 1 - up to 2 kV, 2 - up to 35 kV, 3 - more than 35 kV.
Application conditions
Wires are only used for distribution inside electrical devices. In other cases, a cable is used. This is dictated by the specifics of the equipment, the need to use a large number of cores. In addition, they have increased protection against damage.
Life time
The service life of the cable can reach 30 years or more due to the presence of double protection in the form of insulation and armor. The wire can last about 2 times less.
Supply voltage
Depending on the scope of application and according to the PUE, it is important what current-carrying power a cable or wire has. The first type is equipped with at least double protection and increased resistance of the insulation material. It can be used for high voltage, reaching hundreds of kilovolts.
Wires are used for voltages up to 1 kV. For this reason, all production and high-rise lines are assembled exclusively from cables, and the use of wire is realized for the assembly of electrical appliances.
Choice between cable and wire
It is necessary to choose a cable and wire based on the conditions in which it will be used.
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