Electrical wiring colour code.

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What is the electrical wiring colour code? This is a system where the colour of a wire represents the function of a wire in a circuit. There are a lot of electrical wiring colour codes. There is the American wiring colour code and the British wiring code.

I am not saying that there are only two electrical wire colour code systems in the world. There is even the Chinese wiring colour code. I am very much conversant with the British electrical wiring colour code. Therefore, I will restrict myself, to discuss the British electrical wiring colour code system.

Electrical house wiring colour code.

Electrical house wiring colour code refers to the colours of cables that are used in domestic or residential premises. Here the colour code can be grouped into two. The first group is for the colours of cables is used in the lighting and power circuits of a house.

The other group is for the colours that are used in wiring home appliances. The first group of cables can be divided into two. The first being the colours used in a single-phase house installation. The second being colours that are used in a three-phase electrical installation.

What is the colour code for single phase installation?

To answer this question correctly, I must establish or explain what is a single-phase installation? A single-phase installation is an electrical installation that has one live or hot wire supplying the house.

This is one cable carrying electric power with one cable being the return path for electric power. The cable that is the return path for electric power is called a neutral wire.

I have mentioned two cables that is neutral wires and live wires. These are not the only cable that is used in single-phase installations. The last but not the least cable is the earth wire.

The colours for a single-phase installation are::

Phase wire or live wire the colour is red.

Neutral wire the colour is black.

Earth wire, it can either be bare or green or green with yellow stripes.

In single-phase domestic or residential appliances, the colours are different. for the live wire you use brown for neutral it’s blue then for the earth you use green/yellow cables.

Electrical wiring colour code for three phase installation.

In three-phase installations, you have three wires that are live with one neutral wire. There is some residential house that requires a three-phase power supply. In such installation, you need a three-phase power supply.

For the three phases, you use red yellow and blue. Then you use black as a neutral. The three phases are named as:

  1. Red phase
  2. Yellow phase
  3. Blue phase
  4. Black for the neutral.

I must mention that three-phase machines do not need a neutral wire for them to operate. I mention the neutral wire because you need it for socket outs and lighting circuits to work. Three-phase machines use 3 phases and earth. The colour for the earth cable is the same as in single-phase installations.

Final thought on wiring colour code.

There is a lot of colour code for electrical wiring. In this article, I have limited myself to talk about the colour code that is used in the British electrical wiring colour code. What is the code for your country? I would like to learn from you. Share your thoughts in the comments section below.

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