What are cables?
The cables are a set of metallic threads, usually made of copper (due to its level of conductivity) or aluminum (due to its low cost), which allow for electricity to flow from one point to another. Usually, they have a protective insulating wrap or hose so that the current doesn’t flow outside of them, a layer of filler to keep the circular shape of the cable, and the outermost covered layer made with materials that are resistant to heat, rain, etc.
What is wiring?
This is the set of cables, connectors, channels, and terminals that are part of an electrical network. Together, they act to transport emissions from one emitting device to another receiving one.
A wiring network is designed in such a way that the cables are the proper length to prevent voltage drops and facilitate their assembly. It must also have contact elements with the consumption devices to which the cables will be attached and carry out the transfer of the electric current.
What types of cables are there?
The following are the most commonly used cables in electrical installations:
- According to the number of conductive wires: they can be unipolar, multipolar, or hoses.
- According to their structure: they can be flexible or rigid, flat or round, have a copper-plated core (commonly known as coaxial), braided or intertwined, have insulation or not, etc.
- By type of conductor: bare or insulated wire, a flexible cable or cord conductor, etc.
- According to the properties of the coating: there are different denominations to differentiate between them, 1-T (thermoplastic), 2-H (heat resistant up to 75ºC), 3-HH (heat resistant up to 90ºC), 4-W (water and moisture resistant), 5-LS (low smoke, low emission of fumes and other polluting elements), 6-SPT (service parallel thermoplastic, also known as a duplex cord).
- According to the type of insulation: thermoplastics or thermosets.
How are electrical cables classified according to their voltage?
According to the voltage at which they operate, the wires are classified as:
- Low voltage cables (up to 1,000 volts): used for household installations where energy passes through transformer stations located at the same place of consumption.
- Medium voltage cables (up to 30 kW): used to distribute the electricity generated at electrical substations to transformer and distribution plants that supply the current through a wiring system.
- High voltage cables (up to 66 kW): used to transport electricity from generating stations to electrical substations; characterized by their insulating material, which prevents the loss of energy. This type of wiring is installed in towers or underground, away from urban areas so that accidents do not occur due to electromagnetic waves.
Transporting electrical energy is done at high voltage to reduce the risk of loss. The higher the voltage, the lower the current required for transportation and, accordingly, the lower the power loss on the carrier cables will be.
What do the colors of the wires mean?
The color-coding of cables is governed by the International Electrical Commission Standard IEC 60446. It is used to identify the insulating layer of cables and to differentiate the function of each. With this in mind, each color means the following:
- Green and yellow: grounding wires. They don’t transport energy but usually divert it in the event of an electrical failure, preventing possible electrocutions.
- Blue: the neutral wire that, in the past, was identified with the color red. In some countries, such as the United States, this function is also assigned to white cables.
- Brown, black, or grey: phase cable par excellence; it is responsible for transmitting the electric current.
- Colors with stripes: these serve as a guide since these are neutral, such as blue or white, which help identify which neutral wire goes with a different colored one.
- Other colors: used for current or charging functions. The most common is red, and they are usually used in installations where there are many cables so that they can be easy to identify and then differentiate their use.
What types of outlets are there?
- Ground connection: these do not carry electrical current and have a protective function: they go to the electrical panel and from there to the ground outlet, carrying the current underground. The cable captures and ejects the electric current in case of a short circuit.
- Phase: this is where the current enters and has a voltage of 220 or 230 kV, which is why only professionals are authorized to work with it.
- Neutral: provides a way for the electric current to go back to the source.