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Last updated: September 14, 2025

Switch in Two Way Switch Wiring Diagram Explained

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2 Way Switch

2 Way Switch

A switch that controls one device from two locations

Single Phase Board Switch

Board Switch

A control switch used to operate single-phase electrical loads

Single phase Light

Single Phase LED Light

Energy-efficient LED light for single-phase supply

Single phase Light

Well Light Holder

Recessed light holder typically used in ceilings/walls

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Fluorescent light connection

Learn how a switch is connected in a two-way switch wiring diagram to control one light from two locations using COM and traveler connections.

light control from two switches

In a two-way switch wiring diagram, the first switch uses the Line to the COM, two traveler wires run to both switches, the second switch uses the light as the COM and Neutral as the lamp.

lamp connection two way switch

A two-way switch wiring diagram is used to illustrate how to use two SPDT (Single Pole Double Throw) switches to turn one light on or off in two different locations, like a staircase, hallway, or bedroom. The purpose of each switch is to switch the line (phase/live) to the traveler wires or to the common (COM) terminal.
The Line of the first switch is connected to the COM terminal. Two traveler wires interconnect L1 and L2 of the first switch and L1 and L2 of the second switch. The lamp (load) is attached to the com terminal of the second switch. The Neutral is straight to the lamp. Any switch can be flipped to switch the current on or off at either point. This is a simple and intelligent method of wiring commonly applied in homes and buildings.

Work / Installation (Inputs → Outputs)

  • Input: Line (Phase) → Switch 1 COM
  • Travelers: Switch1 (L1/L2) → Switch2 (L1/L2)
  • Output: Switch2 COM → Light → Neutral

Thus, any switch can turn the light ON or OFF.

Testing and Final Adjustments

Once wired, restore power and test switches. Flip Switch 1: This should be a light that goes ON or OFF. Flip Switch 2: The light is supposed to flip once more. Repeat a couple of times to ensure smooth running. When you find that the light will only work in a single switch position, verify the connections to the COMs - they can be reversed with traveler terminals. Make sure as well that you connect Neutral only to the light, but not to any switch. Tape exposed copper ends and tighten all screw terminals. Be safe and apply correct color codes (brown/red Line, black/blue Neutral, and green/yellow Earth). And finally, label the switch terminals in a way that will allow them to be easily troubleshooted in the future.

Frequently Asked Questions - Fluorescent light connection:

What is a two-way switch?

A two-way switch allows one light to be controlled from two different places.

Which terminal gets the Line wire?

The Line (phase) wire connects to the COM terminal of the first switch.

What is the traveler wire?

Traveler wires connect L1 and L2 between the two switches.

Where does Neutral connect?

Neutral goes directly to the light, not through the switches.

Can I use LED lights with two-way wiring?

Yes, two-way wiring works with LED, CFL, and incandescent lights.

What if the light only works in one position?

Check COM and traveler connections; they may be wired incorrectly.

Can I add more switches?

Yes, add a four-way switch between the traveler wires to control from more points.

Is earthing required?

Yes, proper earthing ensures electrical safety for the system.

What are common uses of two-way switches?

They are used in staircases, corridors, and bedrooms where two control points are needed.

Is two-way switch wiring safe?

Yes, if correctly installed with proper insulation and circuit protection.

Rojony Khatun

Rojony Khatun

CalculatorToolsProject

Rojony Khatun is the creator of a free online tools website designed to simplify everyday and engineering-related calculations for students, professionals, and hobbyists. The platform offers a wide variety of basic and advanced calculators across key categories, including Electrical Calculators, Electronic Calculators, and Time & Date Calculators, helping users solve problems quickly and accurately.