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Wiring Colour Guide: AC + DC Cable Colours

Knowing the various wire colours in the world of electricity can be quite confusing. It’s like trying to grasp the meaning behind every colour in a rainbow.

Such information can be overwhelming for someone who isn’t an expert in providing electrician services. That’s why we’ve prepared a guide to help you understand what these different wire colours mean.

In this post, we’ll talk about the different wiring colours for single-phase and three-phase setups.

AC Wiring Colour Guide

There are two types of wiring you’d find common in the electrical world: AC 240V, also called single-phase, and 415V, known as three-phase. Each one has its own set of unique wire colours. Let’s take a closer look below.

AC 240V Wiring Colours

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

Active Cable Colour

The active cable in 240V AC wiring is easy to identify thanks to its red colour. This hue helps distinguish the live wire. It’s essential to accurately identify this wire to avoid any types of electrical faults from happening.

Neutral Cable Colour

Black is the colour for the neutral cable in a 240V AC setup. This coding is vital to ensure electricians can easily see which wire completes the electrical circuit by returning the current to the source.

The Wiring Colour Guide_ AC + DC Cable Colours

Earth Cable Colour

The earth cable colour in 240V AC systems is marked as green/yellow. This wire is essential in preventing electric shock. It does this by providing a path to the ground in case of any electrical system faults.

AC 415V Wiring Colours

The following are the wiring colours for 415V three-phase AC wiring:

Active Cable Colours  

The active cables in 415V AC systems are distinctly marked as red, blue, and white. These shades are used to differentiate the three phases of an electrical circuit.

Neutral Cable Colour

The neutral cable colour in the 415V AC setup is the same as that of the 240V system, which is black. The consistency aids in recognising that the cable serves to complete the electrical circuit.

Earth Cable Colour

Just like the 240V AC system, the earth cable in a 415V AC configuration has the same green/yellow combination. Such standardisation in these systems helps quickly identify the safety wire.

DC 12V/24V Wiring Colours

The following are the wiring colours designed for DC 12V/24V wiring:

Positive Cable Colour

In both DC12V and 24V systems, the positive cable is normally coloured red. This easily recognisable shade helps quickly identify which cable carries the positive charge. It’s also essential in setting up or troubleshooting DC electrical circuits.

Negative Cable Colour

The negative cable in DC 12V and 24V configuration is a standard black. This hue contrasts sharply with the red positive cable. This provides electricians with a clear visual cue to differentiate the return or negative path in 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 ‘neutral’ and ‘active’ are used in alternating current systems. Active means the wire carrying the current from the power source, while neutral refers to the return path for the current.

On the other hand, direct current (DC) systems use ‘positive’ and ‘negative’ to denote the current flow’s direction. The positive is the source of power, while the negative is its return path.