Wire Colour Codes

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Written By Tristan Cameron

If you’ve ever looked behind a wall in your home, you’ve most likely seen a rainbow of coloured wires. It seems complicated, and it is. Every colour has a different purpose, and some have changed over time.

Every country has its own set of wiring rules; in Australia, it’s been reduced to four colours, blue, brown, green, and yellow.  

But what about the red, grey, and black you’ve seen? See! It is complicated.  

We’re going to break it down for you now.

Wire Color Codes

Colour Wire Type Purpose
Green and Yellow Earth For safety, connects to a metal casing and diverts power to the ground in case of a surge.
Brown Active Carries electricity to power points, light switches, and appliances. Must connect to earth and neutral wires.
Blue Neutral Takes electricity away from appliances, situated at the end of the circuit.
Wire Type Former Colour Replaced With
Earth Green Green and Yellow
Active Red Brown
Neutral Black Blue

Why Are There Different Colours?

Different wires serve their own unique purposes in a building. Without a colour coding system, knowing which wire to connect to what circuit would be impossible.

Firstly, it’s not the actual wires that are colours; it’s the casing around them. But for simplicity, we refer to the wires as having their own colours.

Wire colours in Australia have changed over time. Last century the three primary ones were Green, Black and Red. Yellow was introduced before 2004. 

The current wiring codes in Australia are different, and any property that hasn’t been renovated since 2004 most likely won’t be up to standard.

Here’s what the current status in Australia is. If you feel that the wiring in your property doesn’t match, contact us immediately at North Shore Electricians. Your house may need a complete rewiring.

Current Wiring Colours in Australia

 Here’s a breakdown of the four colours now used in Australia and their purpose.

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ColourWire TypePurpose
Green and YellowEarthVitally crucial in any electrical wiring is the earth. It’s installed for safety reasons. Its primary purpose is to connect the cable or appliances to a metal casing, diverting power to the ground in case of a surge. Without earth wires, electrocution can happen.
BrownActiveThe brown wire is the one that brings the electricity from the circuit to power points, light switches, and appliances. It must be connected to the earth and neutral wires, too, so electricity can be diverted in the case of an emergency.
BlueNeutralThe blue wire acts in the reverse of the brown wire and takes the electricity away from appliances. It’s situated towards the end of the circuit and picks up the charge once it’s passed through the live and earth wires.
Wire Colour Codes in the Past
Different colours were used for all three wires in the past; here’s the replacement chart:
Wire TypeFormer ColourReplaced With
EarthGreenGreen and Yellow 
ActiveRedBrown
NeutralBlackBlue

Single and Three-Phase Wiring

Here’s where it gets a little more complicated. Single-phase wiring relies on the blue, brown, green and yellow concept. Three-phase wiring, on the other hand, has another two colours. Here’s more detail.

Single-Phase Wiring

Single-phase wiring connects two wires; its purpose is to efficiently deliver 230 volts of electricity across a circuit. It contains dual active wires and a neutral one. The active wires can be red and black.

Most older homes are wired with the single-phase concept.

Three-Phase Wiring

A three-phase connection has a 400-volt separation and brings a lot more power into a building. It consists of three active wires and a neutral one. The active wires might be brown, black, or grey.

With the increase in the amount of electricity we consume daily, we recommend upgrading your electrical switchboard to a three-phase system.

Who Can Work With Live Wires?

Some DIYers like to tinker around with wires, but we don’t recommend it. You’ve all seen movies where the hero is told never to cut the red wire, and this is correct. Or is it? 

As you’ve just read, the colours have changed over time, and your property may have a mix of all six. If the building has a three-phase system, it’s even more challenging to know if it’s correct or not.

Mixing them up and cutting or removing the wrong ones can be dangerous. 

The best idea is to let one of our qualified professionals at North Shore Electricians take care of all your wiring needs.

Any of our team can work with wires; it’s only if you need access to the street mains that we need to send a Level 2 electrician to action the task.

Contact us today so we can meet all your wiring requirements.

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