Two-way switches and wiring guide
Two-way switches are a common part of modern homes and offices. A two-way switch is used to control a component like a light bulb or a series of them using two different switches.
In the UK these systems are called two-way switch systems however in other parts of the world they’re referred to as three-way switches.
Where you’ll see a two-way switch
Two-way switches are used all over houses, offices and warehouses, they’re a very common addition to all kinds of applications.
In a house, most of the time your landing lighting will use a two-way switch system as well as hallways and often anywhere an entrance or exists is present. You may also find this type of system in bedrooms where a light switch is close to the bed as well as by the door for convenience.
The likelihood is that you’ve come across a two-way system at some point regardless of the type of property you’re standing in.
How two-way switches work
With a basic understanding of how a simple lighting circuit works, you’ll get a good grasp of how two-way switches will work too. In a lighting circuit, you’ll find a positive terminal connected to a wire. That wire will be connected to a bulb which will in turn have a wire connected to a negative terminal.
However, a two-way switch circuit will work differently. In a two-way system, the switch will move the circuit from one terminal to another. This, in turn, will either break the circuit or create a circuit depending on the position of the other switch in the circuit.
Two-way switch diagram
How to wire a two-way switch system
Step 1: Turn Off Power
First and foremost, turn off the power at the main circuit breaker. Double-check with a voltage tester to ensure no electricity is running to the wires you’ll be working with.
Step 2: Gather Your Tools and Materials
You will need two two-way switches, electrical wire (typically three-core cable for two-way systems), wire cutters, a screwdriver, electrical tape, and a voltage tester. Make sure you have all the necessary components ready before starting.
Step 3: Understand the Wire Connections
In a two-way switch system, you’ll use three types of wires:
- Live wire (L) – Provides power from the source.
- Two Traveller Wires (L1 and L2) – These wires link the two switches and allow them to "talk" to each other.
- Neutral Wire (N) – Completes the circuit to the light.
Step 4: Connect the First Switch
Connect the live wire from the power supply to the common terminal (COM) of the first switch.
Connect the two traveller wires to the L1 and L2 terminals on the first switch. These wires will connect to the second switch.
Step 5: Connect the Second Switch
Run the two traveller wires from the first switch to the L1 and L2 terminals on the second switch.
Connect the common terminal (COM) on the second switch to the live terminal of the light fixture.
Step 6: Connect the Neutral Wire
Connect the neutral wire from the power source to the neutral terminal of the light fixture. This will complete the circuit.
Step 7: Secure All Connections
Make sure all wires are securely fastened to their respective terminals. Use electrical tape to cover any exposed wires or terminals to prevent short circuits.
Step 8: Restore Power and Test
Turn the power back on at the circuit breaker. Test the system by toggling each switch. Each switch should be able to turn the light on and off independently.
Two-way switch systems are a practical and convenient addition to both homes and offices. They offer enhanced flexibility by allowing you to control lighting from multiple locations, which is especially beneficial in spaces like staircases, hallways, and larger rooms. This increased convenience improves everyday functionality, making it easier to manage lighting without having to walk across a room. In offices, two-way switches help maintain productivity and accessibility, especially in shared workspaces or meeting areas. Whether you are upgrading your home or improving an office environment, installing two-way switches is a smart choice for better lighting control, enhanced comfort, and modern functionality.
Browse our range of sockets and switches including BG Evolve, BG Nexus as well as Knightsbridge and more.
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