Do you know the difference between wires and cables? There is a wide variety of electrical wires and cables on the market today, and their applications are the most diverse, but do you know these applications? Do you know what is the best type of cable to be applied in the various functionalities of electrical installations? Do you know the importance of applying the right type of cable or wire within electrical installations? If your answer is no or if you have any questions on the subject, come with us to learn a little more, because in this article we will cover everything about cables and electrical wires without mysteries.
Difference between cable and electrical wire
Electrical cables and wires are extremely important within electrical installations, they are responsible for conducting electrical current safely to the point of demand within the installations. Without these devices, there would be no generation, transmission and distribution of electricity.
Electric cables and wires have the same purpose, as they are used to conduct electric current, but are manufactured differently. Internally conducting wires are manufactured with just one wire, so the wires have the characteristic of being rigid due to their constructive shape, is known as solid cables. Conductive electrical cables, in turn, are manufactured internally by several interlaced conductor wires, which make them more flexible.
Conductive electrical wires
As the conductive wires are internally formed by only one wire, the larger its cross-section, the less flexible the electric wire will be. Currently, the applications of electrical wires are very specific, as they cannot be subjected to sharp curves, as they can break due to the low malleability of the conductor.
Another problem with this cable is how much it is necessary to make the splice of rigid wires with flexible wires, for that it is necessary to use splice gloves, or proper devices to avoid the bad count and heating of the splice.
These wires are well applied in aerial networks, where it is necessary that the conductor has a high resistance, to prevent it from breaking between one pole and another, where there is the effort of the weight of the electric wire itself. Wires are known in the market as solid wires, composed of only one conductor, these devices are still widely used in telephone applications and in abrasive areas where the electrical conductor needs to be buried or subjected to high pressure.
The electrical cables are formed by several small interlaced conductors, which make them extremely flexible. These conductors withstand being subjected to closed angles within electrical installations, due to their high malleability, they are also applied between two mobile parts of industrial electrical installations and machines, as they do not fatigue and break easily.
The electric cables, being flexible, allow splices with a greater electrical contact, avoiding bad contact and heating of the cables in electrical installations, the malleability of the electrical cables allows it to be subjected to sharp curves and folds, without being damaged.
Electrical cables are classified according to their cross-sectional area, that is, their cross-section, the greater the amount of electrical current transmitted by a cable, the greater the cross-section of the conductor. Observe the classification of the main classes of conductor cables used:
- Class 03 = Composed of 7 conductors = rigid classification;
- Class 04 = Composed of 45 conductors = Flexible classification;
- Class 05 = Composed of 75 conductors = Extra Flexible classification
In technical language, a stranded cable is a cable made up of twisted wires that can be isolated between them or not, in addition to the insulation that covers the entire set of wires. The ABNT NBR NM 280 standard defines the stranding classes with degrees of flexibility.
Types of Wires and cables application and characteristics
Este tipo de fio geralmente é fabricado em cobre e o material utilizado para a isolação do fio é o PVC, Policloreto de polivinila (ou policloreto de vinil) que é um tipo de plástico. Podemos encontrar no mercado este cabo suportando a tensão elétrica de até 750V.
Este tipo de fio é aplicado em quadros elétricos, tomadas, chuveiros e em instalações residenciais. As aplicações industriais deste fio são mais restritas e não muito usuais, se limitando a aplicações em que não é necessária a flexibilidade do fio.
A principal característica deste cabo é pouca flexibilidade não deve ser dobrado muitas vezes durante a instalação, pois existe grande chance que o material venha ser fadigado e o fio venha romper, gerando a interrupção da corrente elétrica.
We can find these wires usually in the nominal section, or popularly called as gauge (thickness of the wire), varying from 1.5mm² to 10mm².
Flexible cable and rigid cable
This type of cable is usually made of copper and PVC, polyvinyl chloride is used for insulation. We can find on the market two levels of insulation for this type of electric cable, the most common has 750V insulation, the other type has a thicker insulation layer, so it can insulate up to 1KV. The applications of these cables are diverse, ranging from residential installations to even industrial applications.
The flexible cables, because they are easy to install and very malleable, are easier to be handled, since they slide in the conduits and make the necessary curves of the piping, being an ease at the time of installation, depending on the case and need. Manufacturing with several fine wires allows them to be folded, which makes them perfect for industrial and machine applications.
Because they are flexible, we can find them in several cross sections, or several sizes of gauges, the most used vary between 1mm² and 25mm², but that can reach up to 300 mm².
This type of cable has great flexibility, they are manufactured in the same way as flexible cables, the big difference is that they are usually made up of two or more cables and in addition to the conventional PVC protection, they also have mechanical protection, plus an insulation layer, enclosing the cables in a single cable, but the cables remain isolated from each other in this outer layer.
Due to the great safety in relation to the leakage of current to earth and its great flexibility, this type of cable is widely used for connections of household appliances. They are also used in the automotive market and widely used for industrial applications, such as steel and mining.
We can find PP cables with two, three or four conductors on the market, they can be found with the nominal section from 1 to 500 mm². Its sheath may be black or white, but the sheaths of the internal cables take the colors in accordance with the NBR5410 standard
These types of wires and cables are recommended for the installation of small appliances, portable appliances and lighting objects, such as lamps and chandeliers. Parallel cables are also made of copper wires and are considered flexible. Its thickness varies between 2 × 0.5mm² to 2x4mm².
It is important to understand the differences in the types of electrical wires and cables to choose the ideal one according to the need, whether for residential, building or industrial application. Each project has its specifications, and the need during the project may vary. We must also take into account voltage and insulation level of the cables, right? For this reason, it is always recommended that a trained professional accompany you, or assist in these decisions, to choose the best electrical cable according to your need. Below we provide a video that will help you a lot when choosing the best electrical cable: