Electrical wires form the backbone of every house’s electrical system, powering your appliances on every occasion. But have you ever wondered what would happen if they’re handled incorrectly? Well, if you don’t handle electric wires correctly, they can be dangerous for both regular people and skilled electricians. This is why it’s crucial to know how to read wire colour codes. Standards for identifying wires differ from country to country. But the criteria for electrical wire colour code are practically the same everywhere.
And the colour code of wires has been a topic of concern for quite a long time, which is why, in this article, we’ll dive deep into wire colour code and understand it carefully.
What is an Electrical Wire Colour Code?
There is a standard colour coding for electrical wires that helps you figure out what each wire does in the circuit. Globally, there are many standards that are set that decide these colour codes. These aren’t just something someone one day woke up and agreed upon, but hard and fast laws. Let’s discuss these standards one by one.
Indian Electrical Wire Colour Code Standards
In India, as we mentioned earlier, RGB, or Red, Green and Blue Wires are used. These wires have different purposes, which the table below will explain.
| Wire Color | Type / Function | Description | Connection Rule | Common Use |
| Red | Live / Phase Wire | Carries electric current from the power source to the appliance or load. Common in single-phase connections. | Should not be connected to another red or black wire. | Switches, lighting circuits, and fans. |
| Black | Neutral Wire | Returns the current back to the power source. Though neutral, it still carries current. | Connect black to black only. | Completing the circuit in residential wiring. |
| Green | Earth / Ground Wire | Provides a safe path for fault current to the ground, preventing electric shocks. | Connect green to green only. | Used in sockets, ACs, geysers, and heavy appliances. |
International Electrical Wire Colour Code Standards
Internationally, a different electrical wire colour code is permissible, which is explained in the table below.
| Wire Type | Common Colors | Function / Purpose | Connection Rules | Notes / Common Uses |
| Ground (Earth) Wire | Bare copper or Green (sometimes Green with Yellow stripe) | Provides a safe path for electrical current to the ground in case of a fault, preventing electric shocks. | Should only be connected to other ground wires (never to live or neutral). | Found in all grounded systems and appliances; ensures safety. |
| Neutral Wire | White or Grey | Carries current back to the power source, completing the circuit. | Connect only to other neutral wires; never tape or recolour. | Required by the National Colour Code (in the US); indicates return current path. |
| Hot / Live Wire | Black (most common), Red, Blue, or Yellow | Carries electrical current from the power source to the device or load. | It should never be connected to neutral or ground wires. | Black – primary live wire; Red – second live in 240V; Blue/Yellow – used in switch legs or multi-way switches. |
Electrical Wire Colour Code Chart
Now, there are different colour codes for different types of electrical wires as well. Mainly, they are classified into 3 types, AC, DC and Earth/ground Wire colour codes. Let’s understand each one by one to understand it better.
AC Wiring Colour Code
The table below explains the colour code for AC wiring systems. These electrical wire colours are used when AC connections are involved.
| System Type | Wire Function | Wire Color | Description |
| Single-Phase | Live (Phase) | Brown | Carries current from the power source to the load. |
| Neutral | Blue | Returns the current back to the power source. | |
| Earth / Ground | Green / Yellow | Provides a safe path for fault current to the ground. | |
| Three-Phase | Phase 1 (L1) | Brown | First live wire in a three-phase circuit. |
| Phase 2 (L2) | Black | The second live wire in a three-phase circuit. | |
| Phase 3 (L3) | Grey | The third live wire in a three-phase circuit. | |
| Neutral | Blue | Common return path for all three phases. | |
| Earth / Ground | Green / Yellow | Safety grounding wire to prevent electric shock. |
DC Wiring Colour Code
DC wiring connections generally have 3 types of wires, and as expected, each has a different wire colour meaning.
- Positive: Red
- Negative: Black
- Earth: Green/Yellow
Earth/Ground Wire Colour Code
The earth wire in each setup has a separate colour. This is because it allows the current to flow into the ground during any faults. Most electrical wiring colour code standards require them to be either Green/Yellow, as most electrical connections tend to use them, including AC and DC.
Colour Codes for Different Applications
Well, colour codes also differ based on applications. For example, the wire colour code India mandates different electric cable colours for both residential and industrial wiring. Let’s understand them better.
Residential Wiring Colour Codes
Most residential houses follow the standard wiring codes, Brown (live), Blue (neutral), Green/Yellow (earth). These are the common wire colour codes India follows.
Industrial and Commercial Wiring Colour Codes
The industrial standards are different, as the table below explains.
| Wire Function | Color Code | Label / Marking | Safety Practice |
| Phase 1 (L1) | Brown | Mark as L1 | Ensure proper labelling to avoid phase mix-ups. |
| Phase 2 (L2) | Black | Mark as L2 | Verify phase rotation before connecting equipment. |
| Phase 3 (L3) | Grey | Mark as L3 | Keep all live wires insulated and clearly identified. |
| Neutral (N) | Blue | Mark as N | Connect only to the neutral terminal or bus bar. |
| Earth (E) | Green / Yellow | Mark as E | Always connect to grounding points for safety. |
Importance of Following Electrical Wire Colour Codes
There are a lot of reasons why the electrical wire colour coding system is important:
- Safety: Using the right colour for the wiring ensures that electrical systems are connected correctly, which lowers the chance of getting a shock or starting a fire.
- Efficiency: Colour coding makes it easy to find and fix errors or update the system. Electricians can rapidly tell which wires are which without having to test each one.
- Compliance: National electrical regulations say that wiring colour codes must be followed. This is important for both legal and safety reasons.
Conclusion
These standards, be they national or international, are meant for the safety of people and electricians who work on your wiring. These electrical wire colour codes help build compliance and efficiency as well.
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FAQs
1. What is the standard electrical wire colour code in India?
In India, the standard electrical wire colour code is Brown for Live, Blue for Neutral, and Green/Yellow for Earth as per IEC standards.
2. Which colour wire is used for the earth or ground connection?
The Green/Yellow wire is used for the earth or ground connection.
3. How does the cable colour code benefit electricians and homeowners?
Cable colour codes help identify wires easily, ensuring safe installation, maintenance, and fault detection.
4. What is the purpose of wire colour coding?
Wire colour coding ensures electrical safety and standardisation by distinguishing live, neutral, and earth wires.
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