Neutral cable, what is it and where does it come from?

Do you know what the neutral cable is and where does the neutral cable come from? This is a very common question among electricians and electricity enthusiasts. Thinking about it we will explain what the neutral cable is, how the neutral cable appears, what is the voltage in the neutral cable and what is the neutral used for, come on guys!

Neutral driver: What is it?

The neutral conductor is an element of the circuit or of a certain system, which presents a constant electric current and the difference of null electric potential, regardless of its shape or nature, but even with these characteristics, the neutral conductor can be a conductor active, that is, at some moment or situation the electric current and electric voltage in the neutral conductor may not be null.

It is important to note that the neutral conductor is essential in an electrical installation, especially for low voltage installations. Using the neutral cable in electrical installations, whether residential, building or industrial is essential, because it is through the neutral that we can obtain two voltages, such as 127 V or 220 V, which will also depend on which voltage the concessionaire in each region region provides the consumer.

Where does the neutral cable come from?

Neutral driver: Where does it come from?

The neutral conductor found in electrical installations originates from a three-phase electrical system of a transformer. If you have never noticed a detail about the transmission and distribution system of the dealerships, it is that in the transmission system there are only three conductors reaching the transformers, all of which are phase conductors.

Thus, we can see that at the output of the respective transformer there are four conductors, three of which are phase conductors and one neutral conductor, as we can see in detail the image shown below:

Place where the neutral cable appears.

Knowing that the neutral conductor appears in the transformer, how exactly does this “magic” happen? To facilitate understanding, to know the exact point where the neutral appears, it is important to understand how the transformer works and what are the ways to close the coils of this transformer.

As with three-phase induction electric motors, the transformer coils can also be closed in a star or triangle, and this is how we can understand where the neutral comes from.

The neutral conductor only appears in star closure systems, because internally the transformer has two closures, which are the triangle closure and the star closure, so that the transformer input coils are closed in a triangle and the output coils closed in star, as we can see in the image below:

Star closure and triangle closure.

As we can see, the neutral appears exactly at the point of connection of the coils in the star closing system. At this point, due to the phase lag, the point of union between the coils is mathematically null, that is, their voltage is zero.

In this video below the Mundo da Elétrica channel you have a complete explanation of where the neutral comes from. In the video you can also learn more about the operation of transformers and understand the star and triangle connection systems, check out.

Neutral conductor: What is it for?

The neutral conductor is fundamental in the electrical circuit, because it is the reference point for the phase of a circuit, because between phases the neutral is the one with the lowest electrical potential, close to zero, in addition the neutral can also be used for if a circuit is closed, allowing the circulation of electric current, completing the circuit.

Neutral conductor: How many volts does it have?

Under normal conditions, the neutral should always have the potential of zero volts or as close to that as possible. Therefore, if there is voltage in the neutral it means that there is an imbalance between the phases of the systems, and knowing these details, we can answer another recurring question, that whether the neutral cable gives an electric shock or not!

In order to have an electric shock, there is a considerable difference in electric potential and an electric current, so according to the previous explanation, ideally if you come into contact only with the neutral conductor of a balanced circuit, you should not take an electric shock, but as we already know, in practice none of the facilities are properly balanced,

Knowing such details, we recommend all possible care with the neutral conductor, especially if the circuit has a load connected to it, because despite the neutral conductor has a very low potential, current passes through the neutral cable.

Neutral conductor: What color is the neutral cable?

We cannot end this article without commenting on what the NBR 5410 standard highlights in relation to the neutral. Many do not know, but the neutral conductor must have a specific color, which is indicated by NBR 5410, just as the grounding conductor must contain a different color, which in this case must be green or green with yellow, while the neutral cable must be light blue in color.

We finished another article and hope to have helped clarify the main doubts related to the neutral cable. If you have any questions or curiosity about the subject, leave it in the comments and we will answer it!