What is this?

An electrical circuit, as a rule, has two conductors of different potentials and a current consumer connected. Each end consumer has its own internal resistance, which resists the current and limits, and therefore its dose and density in the conductor, forcing it to do work.

At the moment when the resistance drops sharply to a constant error in the resistance of the conductors, the electric current, which is practically unlimited, increases to a value that makes the cross-section of the conductors small and, passing through them, heats the cores to the temperature of destruction and fusion. Therefore, a frequent satellite of a short circuit is fire, molten metal of conductors and auxiliary mechanisms.

Signs of a short circuit in wires are the smell of burning, ignition and ignition of wires, as well as power outages in a certain area or in the entire network.

How does a short circuit occur?

So, we will consider the main causes of a short circuit in electrical wiring and electrical installations.

High Voltage. At the moment the power rises above the permissible parameters, there is a possibility of an electrical breakdown of the insulation of the conductor or electrical circuit. As a result, the leakage current develops to short-circuit magnitudes, while creating a stable short-term arc discharge.

Ancient isolation. Residential and industrial boxes that have not replaced electrical wiring are the top contenders for an automatic short circuit. Any insulation used in electrical wiring has its own resource. Over time, it is destroyed under the influence of external factors, resulting in a short circuit.

External mechanical impact. Stripping, rubbing of the wire and other impacts on the protective shell that weaken its properties will sooner or later lead to fire and short circuit. For example, in everyday life, a short circuit is often caused by damage to wires when drilling walls. About, how not to damage wires with a rotary hammer read in our article.

Foreign objects. This includes dust of various origins, small animals, parts of neighboring nodes, by accidental contact with electrical conductors, causing a short circuit and its development.

Direct lightning strike. The same thing happens with overvoltage (see above).

An example of the consequences of a short circuit in an electrical installation is shown in the video:

The consequences of a short circuit are burned out parts of the wires and their ignition!

Types of phenomena

The most common is a ground fault, when one phase interacts with ground, or two phases interact with ground, in one or more sections. A short circuit to ground occurs in systems with a grounded neutral and accounts for up to 70% of all cases.

There is also an interphase error when two phases interact with each other. It occurs as a result of a violation of insulation in three-phase equipment.

Well, the last type of short circuit is three-phase, when all three phases interact. The diagram below shows the main types of short circuits:

Methods of prevention

The most effective way to prevent the development of a short circuit and protect electrical appliances and power lines is to install a circuit breaker or fuse. The device (pictured below) when a “short” It will cut off the power immediately, thus preventing a dangerous situation from occurring.

Another way to prevent a short circuit is to timely check the wiring because of this it is possible to visually determine where the insulation is melting and proceed to troubleshooting.

The main causes of short circuit