Why are electrical wires different colours?
The answer is quite straightforward. The colours of your wires weren't chosen randomly; rather, each colour has a specific meaning. This important colour coding system plays a crucial role in ensuring the safety of your electrical installations. Here's everything you need to know for proper electrical wire installation!
The different colours of electrical wires
The electrical world has its own colour language. Each electrical conductor, whether rigid or flexible, has a specific colour that indicates its particular function within the electrical circuit. Standardising these codes allows electricians to quickly identify each conductor's role.
Following this colour code is essential to prevent connection errors and ensure a properly installed and reliable electrical system. These codes may vary from country to country. For example, in some countries, white may be used for neutral wires. Here we present the colour codes used in the UK.
Blue for neutral wires
In all modern electrical installations, blue indicates the neutral conductor. This blue wire allows current to return to the electrical panel. It plays an essential role in single-phase circuits, particularly for powering our outlets and switches. In junction boxes, this neutral conductor is immediately recognisable by its distinctive blue sheath. Being able to identify it quickly is useful for avoiding dangerous connection errors.
Green and yellow for earth wires
The green-yellow combination identifies protective conductors, commonly known as earth wires. These cables act as your protection against electrical accidents. They direct fault currents to ground, preventing the risk of electrocution. These protective conductors ensure that all your electrical appliances are earthed through the main terminal block. Green and yellow wires are essential for preventing electrocution risk. You can use a multimeter or tester to check the continuity of these protective conductors. The cross-section of the earth conductor must be appropriate for the current intensity.
Red, brown and black for phases
Phase conductors carry live electrical current. Red is now the standard colour for single-phase networks. Red, brown and black are also used in three-phase networks.
Orange for live circuits
Orange indicates external voltage supply to electrical boxes and cabinets. These circuits remain live even when the main circuit breaker is switched off because they're powered by an external source.
Other electrical wire colours
Certain specialised electrical installations require other colours. Grey, purple or other colours may appear in special configurations. These variations meet specific technical requirements and always comply with current standards.
Is it mandatory to follow the colour code for electrical wires?
Please note that following the colour code for electrical wires is mandatory: this is a legal requirement! Incorrectly wired connections significantly increase the risk of short circuits and equipment failure. These errors can also cause substantial damage to your circuit breakers and electrical appliances. In France, the NF C 15-100 standard requires compliance with this colour code. This is the standard that governs all domestic electrical installation work.
This standard ensures a certain level of compliance for electrical installations within the country. It's illegal not to comply with the colour coding, both in new installations and renovations.
The idea behind this standardisation is also to make electrical professionals' work easier, as they can easily navigate when installing your electrical system.
The associated risks
Improperly wired connections can lead to various risks: short circuits, equipment failure and even serious damage (fires at connections) to your circuit breakers or electrical appliances. All these situations can be easily avoided with proper wire installation.
To ensure the safety of your electrical installation, One-Elec offers a complete range of wires in colours that comply with current standards. Contact our technician directly if you have any questions. Order directly from our website to benefit from fast delivery within 24-48 hours for all products in stock.
