2 Way Switch Connection | 3 Type of Two Way Switch Circuit Diagram Explanation

Two Way Switch Connection Circuit Diagram Explanation:

Two way switch Connection is nothing but a operating a electrical lighting circuit in two different places such as stair case, ladder etc. In general, to control a circuit we uses switches.

2 Way Switch Connection
2 Way Switch Connection

i.e In our house, if we have a lamp at the top of the stair case means, we may need to operate the same lamp with the single switch and every time we should go to switch place and operate it. It may create unnecessary time delay, panic during night time and physical movement.

To avoid this, we can use 2 way switch connection. In this 2 way switch connection, we need two switches with three terminals on back of the each switches. Three terminal blocks are such as Common, L1 and L2. Refer the picture,

How 2 Way Switch Connection Works:

Let’s control the light fitting by using the two way switch connection. We have electricity and the same is coming from Electricity Board and feeding the light fitting.

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For executing two way switch connection, we need two switches as shown in the figure (It should have three terminal block and the below mentioned snap help us to buy correct two way switch), insulated wire and lamp.

How to find 2 way switch:

Normal switches does not come with the dotted line as indicated below picture. This is a special mark used to identify the switch is connected for two way operation.

Two Way Switch
Two Way Switch

Now, take a live wire and connect it to the common terminal of switch1 (left hand side) and take another wire from common terminal of the switch2 (right hand side) and connect it to a lamp. Now take another wire and joint L1 in switch1 and L2 in switch2.

Place a insulated sleeve on both ends of the wire L1 and L2 to worn out heat in live. Connect another wire from terminal L2 in switch1 to connect in terminal L1 in switch2. Again place a brown sleeve on both ends.

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At this moment, refer the picture Two Way Switch Connection -1, Here Current can pass through switch1 and switch2. But the circuit is broken at switch2. Now, Flip the switch2 (Snap: Two Way Switch Circuit -2) the circuit is complete and current passes through entire circuit and Finally, lamp starts ON.

Two Way Switch circuit  -1
Two Way Switch Circuit -2

Flip switch1, circuit is broken again so the lamp turns OFF but current can still flow through switch2 even circuit is open. Flip switch1 to again to complete circuit or flip switch2 and circuit is complete and light switch ON.

Therefore flip switch1 and switch2 to make to operate the circuit and control the light fitting with two switches.


There are different types of two way switch circuits, let’s see

2 Way Switch Connection Circuit 1:

The second common way to control the light with two switches convert one way switch in to two way again we need two switches and to check backside with three terminals on each with common, line 1 and line 2.

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Connect the live wire in terminal L1 in switch1. Then connect a another wire from terminal L1 in switch1 to terminal L1 of switch2. Connect the common terminal of the both switches 1 and 2 using another wire.

Then run the black wire from terminal L2 of switch1 to terminal L1 of swicth2. Here black colour is used to identification, practically we can use any wire. Place brown sleeve on both ends indicating live. Finally complete the circuit by connecting terminal L2 of switch1 to the lamp.


The electricity is turned ON and the current flows from switch1 to switch2 with circuit but the circuit is in open condition. Flip switch2 to complete the circuits and current can flow through the common and out to the lamp.

Flip switch we break the circuit light fitting and lamp gets OFF.

Flip switch2 we make circuit again electricity will flow to the light fitting.

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2 Way Switch Connection Circuit – 2:

It works almost identically as shown as previous circuit 1. But the out point is L1 of the switch1.

Run the live wire connect in terminal L2 of switch1. Run the brown cable from terminal L2 of switch1 to terminal L1 of switch2. Then run the grey wire from the terminal L2 of switch2 to terminal L1 of switch1.

Then place the brown sleeve at the both ends of wire to indicate the hot live. Run the black wire of common terminal between switch1 and switch2. Finally connect the blue wire from terminal L1 of switch1 to back to light fitting again placing brown sleeve at each end.

When electricity starts the circuit is broken electricity passes through switch1 and switch2 it reaches the dead end.

If we flip switch1 we complete the circuit electricity flow through switch1 into switch2 then back to switch1 and up into the lamp.

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Flip switch2 we break the circuit the electricity flows between the switches and doesn’t reach the light.

Flip switch1 electricity will flow through switch1 over to switch2 across the switch and back over the switch1 and flow to light fitting.

2 way switch connection Circuit – 3: Common L1, L2

Connect the live wire with the terminal L1 in switch1 and join L1 terminal of switch1 and L1 terminal of the switch2.

Run the wire between the terminal L2 of switch1 to terminal L2 to switch2.

Connect the black cable from between the two common terminals of switch1 and switch2. Finally run the blue wire from terminal L2 of switch1 from to light fitting.

When electricity flow through the circuit it flow from switch1 through switch2 circuit is broken so the electricity flows to the dead end. So no light will ON.

Flip switch1 the electricity flows from switch1 over to switch2 and return back to switch1 and light gets turned ON.

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When flip switch2 the circuit gets broken and electricity flows in between the switches itself.

Flip switch1 and circuit gets closed and light gets ON. Flip switch2 again circuit will broken and light will switched OFF.

Image Credit: https://www.youtube.com/watch?v=opoEswRp_jg



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