What types of electric cables exist?

 In this publication of our Blog we are going to show you in a detailed and simple way which types of electrical cables exist, so that you can get to know these products better and choose the right one depending on the use to which it is going to be put.

We will also get to know aspects such as the most common cable sizes and colors, the types of insulation used and the types of conductors.

What do you think if we begin, come on, let's get down to it.

What is an electrical cable?

An electrical cable is an element manufactured and designed to conduct electricity. The main material with which they are made is copper (for its high degree of conductivity) although aluminum is also used, although its degree of conductivity is lower, it is also cheaper than copper.

Parts of an electrical cable

Electrical cables are composed of the conductor, the insulation, a filler layer and a sheath. Each of these elements that make up an electric cable serves a purpose, which we will now explain:

Electrical conductor: This is the part of the cable that transports electricity and can be made up of one or more copper or aluminum wires.

Insulation: This component is the part that covers the conductor, it ensures that the electric current does not escape from the cable and is transported from beginning to end by the conductor.

Filler layer: The filler layer is located between the insulation and the conductor, it ensures that the cable keeps a circular appearance, since in many cases the conductors are not round or have more than one wire. With the filling layer a round and homogeneous aspect is achieved.

Sheath: The sheath is the material that protects the cable from the weather and external elements.

So far so interesting, isn't it? Well, if you think so, let's find out what types of conductors, insulation, cables according to voltages, colors and sizes there are.

Types of electrical conductors

We remember that the conductor is the component that transports electricity.

Bare wire conductor

It is a single wire in solid state, it is not flexible and has no coating, an example of use of this type of conductors is the use for grounding in conjunction with grounding rods.

It is exactly the same as the bare wire conductor with only one difference, in this case the conductor is covered with an insulating layer of plastic material so that the conductor does not come into contact with any other element such as other conductors, people or metallic objects. Insulated wire is used much more than bare copper in homes and offices.

The flexible electric cable is the most commercialized and the most applied, it is composed of a multitude of thin wires covered by plastic material. They are so flexible because they are many thin wires instead of a fat conductor wire so they can be easily bent, they are very malleable.

They are formed by more than one cable or wire, all are joined and wrapped together for the second time, that is to say, they have the own isolation of each conductor plus one that joins all of them in a unique set.

Types of electrical cable insulation

We remember that almost all cables have a coating or insulation layer to prevent them from coming into contact with each other and causing a short-circuit.

The type of insulation that a cable has can be identified by the inscriptions that appear on it, which are abbreviations of the English language. The cables used for installations in homes and offices are: THN, THW, THHW and THWN. The meaning of these abbreviations is as follows:

 1 - T (Thermoplastic): Thermoplastic insulation (all cables have this one.

 2 - H (Heat resistant): Heat resistant up to 75° Celsius (167° F).

 3 - HH (Heat resistant): Heat resistant up to 90° Celsius (194° F).

 4 - W (Water resistant): Water and humidity resistant.

 5 - LS (Low smoke): This cable has low smoke emission and low pollutant gas content. 

 6 - SPT (Service parallel thermoplastic): This nomenclature is used to identify a cord that is composed of two flexible, parallel, plastic-insulated wires that are joined together. It is also referred to as a duplex cord.

What is cable insulation made of?

There are two types of insulation in electrical cable insulation, thermoplastic insulation, and thermosetting insulation.

1. Thermoplastic insulation
2. PVC: Polyvinyl chloride
3. PE: Polyethylene
4. PCP: polychloroprene, neoprene or plastic
5. Thermosetting insulation
6. XLPE: Cross-linked polyethylene
7. EPR: Ethylene-propylene
8. MICC: Coated copper, insulated mineral

Voltages of electrical cables

Depending on the voltage for which they are prepared to operate, cables are categorized into voltage groups in volt ranges.

Very low voltage cables (Up to 50V)

Low voltage cables (Up to 1000V)

Medium voltage cables (Up to 30kV)

High voltage cables (Up to 66kV)

Very High Voltage Cables (Above 770kV)