Wiring Colour Guide: AC + DC Cable Colours

Learning the various wire colours in the world of electricity isn’t easy. It’s like trying to grasp what the different colours of the rainbow mean.

This can be quite overwhelming, particularly for those who aren’t qualified to provide expert electrician services. That’s why we’ve prepared a guide to help you understand what these colours signify.

For this blog, we’ll talk about the wiring colours we use for single-phase and three-phase setups.

AC Wiring Colour Guide

There are two types of wiring in the electrical world: AC 240V, or single-phase, and 415V, also known as three-phase. Each of these wiring types has its own unique set of colours.

Let’s take a closer look at each one below.

AC 240V Wiring Colours

The colours for the 240V single-phase AC wiring are as follows:

Active Cable Colour

The active cable of AC 240V wiring is typically denoted by a red hue. This colour serves as a universal identifier for the live wire, which carries current to the appliance from the power source. Understanding this colour coding is crucial, especially when diagnosing types of electrical faults.

Neutral Cable Colour

For the neutral cable, a black shade is standard. This colour indicates the wire that completes the electrical circuit by returning current to the power source.

The Wiring Colour Guide AC + DC Cable Colours

Earth Cable Colour

The earth cable, vital for safety, is easily identified by its green and yellow striped pattern. This wire acts as a safety measure, providing a path to the ground in case of any electrical concerns.

AC 415V Wiring Colours

The wiring colours of the 415V three-phase AC wiring are as follows:

Active Cable Colours

The active cables in AC 415V wiring are distinguished by specific colours: red, white, and blue. These colours are standard for the three phases of electrical systems.

Neutral Cable Colour

The neutral cable in the 415V AC setup is black, similar to that of the 240V system. This similarity allows electricians to quickly identify the cable that completes the electrical circuit.

Earth Cable Colour

The earth cable in the 415V AC configuration is the same as the 240V AC system: it has a green and yellow colour. Such standardisation helps quickly identify the safety wire.

DC 12V/24V Wiring Colours

For DC 12V/24V, the wiring colours are as follows:

Positive Cable Colour

The positive cable in both DC 12V and 24V systems is coloured red. Such bright colour makes it easily recognisable to help experts identify which cable has the positive charge. This is essential in troubleshooting or setting up DC electrical circuits.

Negative Cable Colour

The regular colour for the negative cable in DC 12V and 24V configuration is black. Such shade differs greatly with the red positive cable to make it easier for electricians to differentiate the negative or return path within the circuit.

Is Active and Neutral the Same as Positive and Negative?

No, active and neutral aren’t the same as positive and negative. The terms ‘active’ and ‘neutral’ are applied when talking about alternating current (AC) systems. Active means the wire carrying current from the power source, while neutral acts as the return path.

On the other hand, direct current (DC) systems use the terms ‘positive’ and ‘negative’ when denoting current flow direction. The positive acts as the source of power while the negative is the return path.