Sometimes people who are completely far from electronics and electrical engineering have to independently carry out work directly related to this topic, so it would be completely useful to find out how wire and cable differ.
Description
The wire is an electrical product that has a light insulating sheath of one or several cores. Wires are vulnerable to mechanical impact, and therefore, if there is a risk of damage at the installation site, the wire receives protection in the form of copper or steel braiding. In addition to protection from external influences, the braid also protects the wire from negative influence electromagnetic interference. The insulating shell, which is usually made of vinyl or rubber, also plays an important role.
Wires are divided into two main types - solid and stranded. Different types wires are used for different purposes and under different conditions. Solid or solid wires can be used without insulation and are most often used in applications where high frequency performance is needed. Stranded wires are more flexible and, as a result, have a longer service life and resistance to mechanical stress.
Cable, in fact, is a system of two or more cores isolated from each other. There are four main types of cable - multicore cables, fiber optics, coaxial cables and twisted pair cables. A multicore cable consists of several mutually insulated conductors; cables of this type are used for installation both indoors and outdoors. The function of twisted pair cable is to transmit a signal - this type of cable was originally developed to create telephone networks more than 120 years ago. Twisted pair differs in that the signal transmitted through such a cable is almost always completely free of any interference. Coaxial cable also transmits audio signals, but due to the coaxial conductors and insulation, the transmission quality of coaxial cable is much higher than that of twisted pair cable.
Comparison
The maximum voltage rating of a wire can be no higher than 1000 V, while cables can withstand almost any voltage.
Cables, unlike wires, are not produced without a sheath and sometimes can even have especially strong protection - armor. Therefore, cables are better suited for laying underwater or underground, since they are less susceptible to external influences and have a longer service life.
Conclusions website
- Essentially, a cable consists of several wires under one or more layers of insulation.
- The cable can withstand almost any rated voltage. The maximum rated voltage of the wire is 1000 V.
- By virtue of design features cables are better suited for laying underground and underwater.
The wire- this is one uninsulated, one or more insulated conductors, on top of which, depending on the installation and operating conditions, there may be a non-metallic sheath, winding or braiding with fibrous materials or wire. Wires can be bare and insulated.
Bare wires
Bare wires are those whose conductive cores do not have any protective or insulating coatings. Bare wires (PSO, PS, A, AC, etc.) are mainly used for. Insulated wires are those whose conductive cores are covered with rubber or plastic insulation. These wires have a braid of cotton yarn or a sheath of rubber, plastic or metal tape over the insulation. Insulated wires are divided into protected and unprotected.
Protected wires
Protected are insulated wires that have a electrical insulation shell designed to seal and protect against external influences. These include wires APRN, PRVD, APRF, etc. Unprotected insulated wire called a wire that does not have a sheath over the electrical insulation. These are wires APRTO, PRD, APPR, APPV, PPV, etc.
Cords
A cord is a wire consisting of two or more insulated flexible or especially flexible conductors with a cross-section of up to 1.5 mm2, twisted or laid parallel, covered, depending on the operating conditions, with a non-metallic sheath or other protective covers.
Cables
A cable is one or more insulated cores twisted together, usually enclosed in a common rubber, plastic, or metal sheath (NRG, KG, AVVG, etc.). The sheath serves to protect the insulation of the cores from exposure to light, moisture, and various chemical substances, as well as to protect it from mechanical damage.
Installation wires
Installation wires are intended for installation of power and lighting networks with fixed installation on outdoors and indoors. They are made with single- and multi-core, with rubber and plastic insulation, unprotected and protected from light mechanical damage. The conductors of the wires have standard cross-sections, mm: 0.35; 0.5; 0.75; 1.0; 1.5; 2.5; 4.0; 6.0; 10.0; 16.0, etc.
How to determine the cross-section of a wire, knowing its radius
Depending on the brand, standard wire cross-sections have certain values. If the wire cross-section is unknown, then it is calculated using the following formula:
where S is the wire cross-section, mm2; n - number equal to 3.14; r - wire radius, mm.
The diameter of the current-carrying wire (without insulation) is measured with a micrometer or. Core cross-section stranded wires and cables are determined by the sum of the cross-sections of all wires.
Types of installation wires
Installation wires with plastic insulation APV, PV are made without sheathing or protective covers, since plastic insulation does not need protection from light, moisture and is resistant to light mechanical stress.
To protect rubber-insulated wires from mechanical damage, light and moisture, sheaths with a folded seam made of aluminum alloy AMC or brass (APRF, PRF, PRFl) or sheaths made of PVC plastic (PRVD, etc.) are used.
The insulation of the wires is designed for a certain operating voltage at which they can be operated for a long time and safely. Therefore, when choosing a wire brand, it should be taken into account that the operating voltage for which the wire insulation is designed must be greater than or equal to the nominal standard value of the supply voltage of 380, 220, 127, 42, 12 V.
The installation wires must match the load being connected. For the same brand and the same cross-section of wire, loads of different magnitudes are allowed, which depend on the laying conditions. For example, wires or cables laid openly are cooled better than those laid in pipes or hidden under plaster. Wires with rubber insulation allow long-term heating of their cores, not exceeding 65°C, and wires with plastic insulation -70°C.
How to decipher wire markings
The wires are marked with letters, after which the number and cross-sectional area of the conductive wires are written down in numbers. When designating a wire, the following structure is adopted. The letter P is placed in the center, indicating a wire, or PP - a flat two- or three-core wire. The letters P or PP may be preceded by the letter A, indicating that the wire is made of aluminum conductors; if there is no letter A, then the conductors are made of copper.
Following the letter P or PP is a letter characterizing the material from which the wire insulation is made: P - rubber, B - polyvinyl chloride and P - polyethylene insulation (APRR, PPV, etc.). The rubber insulation of the wire can be protected by various sheaths: B - made of PVC plastic, N - non-flammable chloroprene sheath (Nairit). The letters B and H are placed after the letters of the wire insulation material - APRN, PRI, PRVD.
If the wire has a braid of cotton yarn coated with varnish, then this is indicated by the letter L, and if the yarn is impregnated with an anti-rot compound, then the letter in the wire brand is omitted. The letter L is placed in last place in the designation of the wire brand.
Wires with flexible current-carrying conductors are marked with the letter G, which is placed after the rubber - P or before the polyvinyl chloride - B insulation (PRGI, etc.). Single- and multi-core wires intended for laying in steel pipes and having a braid impregnated with an anti-rot composition, have the letters TO (APRTO, PRTO) at the end of the brand.
The polyvinyl chloride sheath of the rubber-insulated wires is oil-resistant. Flat wires in the dividing base can be perforated with a hole width of up to 4 mm and a length of up to 20 mm. The distance between the edges of the holes is up to 15 mm. The wires may have marks that make it easier to distinguish the wires during installation.
For indoor and outdoor installations of branches from overhead lines into residential buildings and buildings, special wires are produced that have a supporting steel cable, which is located inside the wire, between its insulated cores. Cable wires are available in 2-, 3- and 4-core types and have rubber insulation or PVC insulation. The conductive cores of the AVT wire have insulation in black, blue, brown and other colors. The installation wires are designed for operation at ambient temperatures from -40 to + 50°C and relative humidity 95 ± 3% (at a temperature of + 20°C).
How to decipher cable markings
Just like wires, they are marked with letters, after which the number and cross-sectional area of the current-carrying conductors are written down in numbers. For electrical wiring, you can use unarmored power cables with rubber and plastic insulation. To protect the core insulation from light, moisture, chemicals, and mechanical damage, the cables are covered with sheaths made of various materials. Metal sheaths made of lead, aluminum and steel are not a protective covering for cables (armor). When cable insulation is made of moisture-proof materials (plastic and rubber), instead of a metal sheath, a plastic or rubber sheath can be made.
Brands of rubber insulated cables- ASRG, SRG, WRG, AVRG, ANRG, NWG; with plastic insulation - AVVG, VVG, APVG, PVG, APsVG, PsVG, APvVG, PvVG.
The first letter in the designation of cable brands, with the exception of the letter A, determines the material: B - PVC compound, P - polyethylene, Ps - self-extinguishing polyethylene, Pv - vulcanizing polyethylene, N - nayrite, C - lead. The second letter determines the insulation material B - PVC, P - rubber. The third letter G indicates that the cable is unarmored.
Power cables of the indicated brands are intended for operation in a stationary state at ambient temperatures from - 50 to + 50 degrees. With relative air humidity up to 98%. The cables are designed to withstand a long-term permissible core temperature of up to 70°C.
Cables of the ANRG and NRG brands have a rubber non-flammable sheath. To connect portable lamps, mobile electrified machines and portable electrical appliances to the network, flexible cables with rubber insulation such as KG, KGN, KLG, KPGSN, etc. are used.
According to Wikipedia, a cable is a structure of one or more conductors enclosed in a sheath. For the uninitiated, the differences between a cable and a wire are absolutely not noticeable, but they exist. Sometimes there are moments in life when it is necessary to determine exactly what their differences are.
Cable
In order to understand the difference between a cable and a wire, you need to consider them in detail. We already know what a cable is. For more detailed study It's time to get acquainted with its classification and varieties. First of all, they are divided into application groups:
- power;
- installation;
- communications;
- management;
- radio frequency;
- optical.
Power ones are designed to transmit electricity. They are laid permanently and used when connecting mobile electrical consumers.
The required elements included in the cable are:
- conductor;
- its isolation;
- shell.
Made from copper and aluminum. Supply voltage – up to 750 kV. Have long term operation (30 years). The best insulation is made from cross-linked polyethylene.
Mounting plates are used for inter-device installation electrical devices. Supply voltage – up to 500 V. The main material of the current-carrying conductors is copper. They are stable in performance elevated temperatures.
Communication cables are used in signaling and wire communications. For example, a corrugated cocoon-shaped waveguide is used in radio engineering and radar systems. Widely used for intercity, interregional and city communications.
Control cables are used for control and lighting circuits in machine tools and other mechanisms with voltages up to 600 V.
RF and optical media transmit energy and signals at specific radio frequencies or in the optical range.
In addition to these groups electrical conductors have a number of other characteristics by which they are classified. This includes parameters such as insulation, shielding, the number of current-carrying cores and their material from which they are made. There are a number of other signs of cable division. The classification of electrical products is described in detail in the ISO 11801 2002 standard.
The wire
From GOST 15845-80 it follows that a wire is a cable connection containing one or more wires, or insulated cores, on top of which there is a light non-metallic sheath. The same GOST indicates that the wire is not laid in the ground, which is different from a cable.
Wires are represented by a wide range of classifications:
- by conductivity;
- section (diameter);
- material;
- type of insulation.
There are a number of other characteristics by which these electrical products are classified.
The types of wires mainly determine their area of use. They may differ from each other in many ways. There are winding, assembly, automotive, connecting, insulated and others. They are not isolated, for example, in air lines power transmission lines (power lines). More detailed information this can easily be found on Internet sites and in numerous videos.
Wire and cable appearance have some similarities. But there are differences between them, and they are clearly visible to a specialist.
Difference between cable and wire
To understand the difference between any cable and a wire, it is enough to have basic knowledge in the field of electrical engineering.
Insulation
The first difference is interpreted by GOST 15845-80. It clearly defines that the wire does not have separate insulation for each current-carrying core. A conductor or a twist of several conductors may be enclosed in some kind of insulating sheath, or may not have it at all. The same GOST determines that each current-carrying core in a cable has its own insulation.
Thus, one of the main differences between the products under consideration will be the presence of insulation on each current conductor and a common insulating shell. If each conductor is in separate insulation, then we have a cable. If there is no insulation, or several bare conductors are enclosed in an insulating sheath - a wire.
Marking
Knowing how to read brands of electrical products, you can also determine the difference between them. What is the difference between a cable and a wire in the markings? Visually – in letters and numbers. In reality it looks like this. There is an inscription on the insulation - AVVGng 3*2.5. After decoding it, we see that we have a cable in front of us. It consists of three aluminum cores. Each with a cross-section of 2.5 mm², is in polyvinyl chloride insulation (PVC). All current-carrying conductors are enclosed in a common sheath, also made of PVC. NG means that it does not support combustion.
A varied number of letters in the marking characterizes the product in many of its parameters. The presence of the letter B in the brand means that the cable is armored, Ш means protection in the form of a hose, P means rubber protection, E means the presence of a screen. By the presence of letters in the marking, it is easy to recognize the type of product and determine the possibility of its use in a particular case.
Electrical wires also have their own markings. It is practically no different from cable markings. The fact is that in electrical engineering the marking standards comply with GOST and are identical for all products. If PuGV is written on the insulation of the product, this means that we have an installation wire of increased flexibility in PVC insulation. More detailed information about the marking of wires can also be taken from electrical reference books or from Internet sites.
Conditions of use
Cable, unlike wire, has found more wide application V special conditions. Having increased protection against mechanical and aggressive damage, it is laid under water. All underground communications are carried out only by him. In addition, they are used in mines, fire hazardous areas, areas with increased corrosive activity and other places.
Wires are used only inside electrical distribution devices. Outside these limits, it is recommended to use cables or conductive bars. As an example, consider the PV-3 wire. This is an installation copper wire with a stranded core. Suitable for use in baths and bathrooms. Does not burn. Found widespread use in installation apartment electrical wiring. It has increased flexibility, which makes it different from other wires.
Life time
As a rule, cables are more durable in use than wires. This is primarily due to the presence of at least double insulation. In addition, some of them are manufactured in an armored shell, which also increases service life. It is generally accepted that average term The service life of this product is 30 years. The wire lasts about half as long.
Voltage
Various sources discuss the difference between cable and wire in terms of voltage. Should this parameter be taken into account? The answer is clear - yes, it is worth it. Based on the fact that the cables have at least double insulation of the current-carrying cores, it becomes clear that they can carry large currents and high voltages.
Therefore, the technical characteristics of products indicate what maximum voltage they are designed for. While cables reach hundreds of kilovolts, wires are typically limited to a maximum of just one kilovolt.
The difference between cable and wire is popularly discussed in this video:
Choosing between cable and wire
When planning construction or renovation, you can decide for yourself what you need to buy - wire or cable. It becomes possible to calculate in advance the required footage of electrical communications. This is necessary primarily in order not to overpay extra money. Knowing the differences between a cable and a wire and installing in in the right place exactly what needs to be installed, increasing the safety of the entire electrical system. This means increased safety, primarily fire safety, of the facility as a whole, be it an apartment or a cottage.
Often the concepts of “cable” and “wire” are used as synonyms, and only specialists knowledgeable in electricity clearly understand that these products are different. Each of them has different technical characteristics, scope of application and design. In some cases, it is possible to use only one of them. To understand the difference between a cable and a wire, it is necessary to consider both products from the point of view of their structure and purpose.
What is a cable?
A cable is a product that contains 1 or more insulated conductors. They can be covered with armor protection if the scope of application involves the possibility of mechanical damage.
According to the areas of use, cables can be:
- By force. Used for transmission and distribution of electricity through lighting and power plants via cable lines. They may have aluminum or copper cores with braiding made of polyethylene, paper, PVC and rubber. Equipped with protective shells.
- Controls. Used to power equipment low voltage and creating lines of control. The main material for manufacturing cores with a cross section of 0.75-10 mm² is copper and aluminum.
- Managers. Intended for automatic systems. Made from copper with a plastic shell. Equipped with a protective screen against damage and electromagnetic interference.
- For transmitting high-frequency (long-distance) and low-frequency (local) communication signals.
- Radio frequency. Thanks to them, communication between radio 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?
A wire is a product made from 1 bare or several insulated conductors. Depending on the laying conditions, the braid can be made of fibrous materials or wire. There are bare (without the use of coatings) and insulated (with rubber or plastic insulation) products.
The conductors in the wires can be aluminum or copper. An important aspect use is correct connection these 2 metals in 1 system due to the high activity of the first element. It is recommended to install electrical wiring from 1 material. Can be combined with connection via terminal.
Aluminum wiring is cheaper. It has high strength and anti-corrosion properties. Copper conducts electricity better. The big minus of a copper core is high degree oxidation in air, which leads to destruction of connections, voltage drop and strong heating of the joining point. To prevent this, the surface of the core is tinning with inactive materials.
Wires can be protected or unprotected. In the first case, in addition to electrical insulation, the product is covered with an additional shell. The unprotected do not have one.
They are classified according to the scope of application:
- Assembly. Used for flexible or fixed. In addition, in the manufacture of radios and electronic devices.
- Power. Used for laying networks.
- Installation. With their help, installation of connections of installations, power transmission systems indoors and outdoors is carried out.
What is the difference between cable and wire?
The difference between a cable and a wire lies not only in the number, type and material of the conductors. Products have different application conditions and power capabilities, methods parallel connection and characteristics of the shell, as interpreted by GOST.
Insulation
The definition of a wire refers to the absence of insulation on each conductor carrying current. During the installation process, it can be installed on a separate element or twist.
In a cable, an insulating layer is required for each core, as well as the structure.
It turns out that if the cross-section shows several cores equipped with a coating and enclosed in one common sheath, this is a cable. The presence of 1 or more bare conductors in insulation is a wire.
Marking
All electrical products are provided with markings that describe in detail their characteristics and purpose. The inscriptions on cables and wires have their own differences.
The wire markings are deciphered as follows:
- The presence of the letter “A” in the first place indicates that the conductor is aluminum. If the first “P” is copper.
- The letter “P” indicates the presence of 1 wire, “PP” - 2 or 3 flat wires.
- The next letter tells about the core insulation material: “P” – polyethylene, “P” – rubber, “B” – polyvinyl chloride, “L” – braided cotton yarn.
- If the shell designation is followed by an "H", this indicates an additional protective layer made of non-flammable nayrite, “B” – made of PVC.
- If the wire contains a flexible current-carrying core, it is designated by the letter “G”.
- Multi-core products with anti-rot 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, absence of a letter – copper).
- Type (“K” – control, “KG” – flexible).
- Insulation (“P” – polyethylene, “V” – polyvinyl chloride, “R” – rubber, “NG” – non-flammable, “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-flammable armor, "2g" - double polymer tape, "Shv" - polyvinyl chloride hose, "Shp" - polyethylene hose, "Shps" - self-extinguishing polyethylene hose).
In addition to these symbols, there are many others that indicate special characteristics. For example, the letter "E" at the beginning of the code indicates that . The same letter in the middle indicates the presence of a screen.
Right after letter designation followed by a digital one, 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.
Conditions of use
Wires are used only for distribution inside electrical devices, as well as when laying a line of 2 and 3 woven products. In other cases, a cable is used. This is dictated by the specifics of the equipment, the need to connect several wires at the same time. 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 may be important what current-carrying force the cable or wire has. The first type is equipped with at least double protection and increased durability of the insulation material. It can conduct high voltage currents reaching hundreds of kilovolts.
Wires can only transmit 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.
Choosing between cable and wire
Knowing the difference between a wire and a cable, you can competently design the electrical system in your home in such a way as to significantly reduce the cost. If you purchase a cable of the required length to establish a low-power connection, it will be unprofitable. In such cases, it is better to give preference to 2 wires woven together.