Electrical wiring is a cabling system which carries currents of electric power to and from electrical devices and lighting fixtures in a structure such as a building or house. It is subject to safety standards for design and installation, and the allowable wire and cable types and sizes are regulated by national and international codes. Whether it is a simple light fixture or an entire electrical circuit, proper and safe wiring can significantly reduce the risk of fires and other hazards.
The choice of materials for electrical wires depends on their conductivity, durability and cost. Copper is one of the most commonly used metals for wiring, due to its highly conductive properties. However, it is also relatively expensive compared to other metals such as aluminum. Therefore, other metals are sometimes used as an alternative to copper, such as silver. Silver is more durable than copper and has a lower rate of degradation from environmental factors, but its higher price tag makes it a less common material for electrical wiring.
When electricity flows through a wire, it creates magnetic fields around its cross section. These fields interact with the metals and other conductive elements within the structure to generate heat. The higher the amount of current that is flowing through a wire, the greater the resulting field and the more heat it produces. When wires are properly insulated and sized for the load they carry, these interactions can be kept to a minimum, protecting people from shocks or fires.
There are many different types of insulated wires that can be used to carry electricity through a structure. Some are pre-cut and soldered to provide a ready-made connection for lamps, appliances and other electrical devices. Others are not, and require that they be cut to the correct length with a wire cutters before being attached to a device or plugged into an outlet. Wires are labelled with a color and number to identify the type, gauge and current capacity they can handle.
Conductors entering cabinets, boxes or fittings are usually covered by a guard to prevent anyone other than authorised personnel from touching them. In areas where the risk of damage is high, such as in a mine, barriers and fencing may be necessary. For temporary wiring with a voltage of over 600 volts, it is important to protect the conductors from abrasion and ensure that all openings into which they enter are effectively closed.
A wire’s thickness is determined by its size, with thicker wires being able to carry more current than thinner ones. However, it is also possible to have too much or too little current in a wire, and using the wrong diameter for the voltage of a circuit can cause overheating which can lead to fires and other safety risks. Performing regular fire risk assessments can help to identify and repair such dangerous situations.