A short circuit is an electrical phenomenon that occurs especially when two electrical wires come into direct contact, usually due to a lack of insulation. The result is a sudden increase in current intensity that can lead to a fire.
In an electrical installation, there are always at least two wires. The electrical current enters through one and exits through the other. Between the two, it passes through an electrical device (a washing machine, a television, a computer, etc.) and makes it work. When the plastic insulating material is damaged, the two wires can touch directly, without passing through a device. The current takes a shortcut, hence the name short circuit. In other words, when two live parts in an electrical circuit come into contact, a difference in current is produced, a large current spike occurs, and at that moment, the electrical phenomenon takes place.
This flash of light and fire that can burn the wires occurs when there is a difference in current, either due to an accidental shock or because a person touches a component of the circuit (known as “touching a metal part”).
How to protect an electrical installation from a short circuit?
Through fuses
This electrical component, which consists of a small wire, conducts current, but unlike a cable, it has a very low melting point, allowing it to interrupt the current when it becomes excessive. This prevents the rest of the circuit from being damaged and thus prevents fires, protecting electrical equipment and installations.
Circuit breakers
These have the same function as fuses. When a circuit breaker’s coil detects a current difference and the heat produced by the spark, it automatically trips. These devices are configured to trip at 10, 20, 30, 40, or 50 Amps.
Residual current devices (RCDs)
These act like circuit breakers or fuses, but they offer an important advantage: excess current is diverted to ground, preventing anyone who comes into contact with it from being affected. The differential is what really saves a human life, for example when a child puts their finger in an electrical outlet (light outlet in Mexico).