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How to Wire a Two-way Switch Light / How Two-Way Switch works

Two way switching Circuit

Two way switching Circuit : wiring connection with working example

Staircase lighting circuit : How to wire using two way switches

In this article, we will show you how to wire a circuit to turn a light on or off from two different locations. We are going to refer to this light control circuit as a two way switching circuit.

Components Required for Two Way Switch Connection 

  • Two 2-way switches
  • AC supply
  • Bulb
  • Connecting wires

SPDT Switches

Before we get started, we need to introduce you to some switch terms.
If we are going to turn a light on and off from 2 different locations, we need 2 Single Pole Double Throw or SPDT switches.

A SPDT is called a 2-way switch in the European Union, and a 3-way switch in North America. A SPDT switch has 3 terminals. It will have one terminal in and 2 terminals out.

Two-way Switch Wiring using Two-wire control

This is the first method to make a 2-way switching connection, this is the old method. If you are going to install a new one then go for three wire control methods.

2-way Switch Wiring using Two-wire control

As you see in the 2 way switch diagram above, you will find that the phase/live is connected with the common of the first 2-way switch. PIN1 & PIN2 of the first switch are connected with the PIN1 & PIN2 of the second switch respectively. One end of the bulb is connected with the Common Terminal of the second switch and another end of the Bulb is connected with the Neutral line of the AC power supply.

How to Connect two way Switch Wiring using Three-wire control

This is the new method to make a 2-way switch connection and it is slightly different from the two-wire control method. This method is commonly used nowadays as it is efficient than the Two-Wire control system.

2-way Switch Wiring using Three-wire control

As you can see in the Schematic Diagram of 2 way switch circuit above, the common of both the switches are short-circuited. PIN1 of both the switches are connected with the phase or live wire and PIN2 of both the switches are connected with the one end of the lamp. The other end of the Lamp is connected with the Neutral line of AC power supply.

Uses of Two-Way Switch:

  • Mostly in the stair case.
  • A big room having two entry/exit gate.
  • Erroneous tripping of safety/circuit protection equipment.
  • To control any AC appliances like fan or light from two places like entry and exit.

Summary :

– A SPDT is called a 2-way switch in the European Union, and a 3-way switch in North America.

– A SPDT switch has 3 terminals. It will have one wire in and 2 wires out.

– Each terminal on a SPDT switch has a name. The input terminal is called Common. The output terminals are called Normally-Open and Normally-Closed.

– Turning a light on and off from 2 different locations requires a 2-way switching circuit.

– A 2-way switching circuit requires 2 SPDT switches.

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