This article is all about the two-way switch wiring works tyoes and examples. Before moving forward let’s know about what kind of Switch it is. It’s also known as a Staircase Switch. For example, a single bulb is controlled by two switches on either side of the Staircase.
WARNING: This article is just for increasing a person’s knowledge or just a theory about the 2 Way Switch. It’s not an installation guide. If you are planning to install this setup at your house then you must consult with an expert as this setup includes a 230V AC supply or depends on where you live.

Outline

Introduction

As we know that Switches are parts of our daily life, we use them everywhere even it’s used 24/7 a day. They are fixed in our homes, office, car, Industries, and many other places. Its also used in gadgets that are used several times in a whole day. For example, mobile phones, laptops, computers, etc. They all consist of multiple switches.
Actually, Switch is an electrical device that is used for the ON and OFF of an electric circuit.

TYPES:

There are numerous types of Switches that are used according to the situation and place of installation. Some of these  types are;
  1. Toggles Switch
  2. Momentary Switch
  3. Rocker Switch
  4. Digital Switch
All types of Switches play the same role of either shutting the flow of electricity or change the flow of power supply. Simply they “make” or ” break” the circuit.
Switches are commonly used to turn ON and OFF the lights, fans, etc, in these electrical devices common Switch is used but there is a unique ????switch known as “Two Way Switch” which is specifically used for fixing Staircase lighting.
 it’s further explained with a different topic such as what are the elements of the 2 Way Switch, types of wires used in it. Usually, a two Way Switch is a single pole with three terminals.
These three terminals are named COM, L1, and L2, and casually the terms COM, 1 Way, and 2Way are used. In one case, COM and L1 terminals are connected and in another case, COM and L2 terminals are connected.
These types of connections are named as “Break before make” design. As it works in such a manner that the first connection is broken to create or make another connection. It’s also similar to a simple Two Terminals Switch, which is simple a make and brake device.
 The given image presents the most used two-way switch that is commonly used in households.

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How to Wire a 2 Way Switch?

As mentioned above in the “Introduction” paragraph the use of a two-way switch with an example of Staircase lighting, as lights can be turned ON at the start of stairs and then at the end of the stair, lights can be turned OFF, simply by Toggling the Switch near the top of Staircase.
There are many ways that show the importance of Two Way Switch connection. There’s also a traditional method which is not used nowadays as time had brought a lot of changes. Another method is the modern and safest one which is commonly used in Industries and in household appliances. Given below is the Wiring method for Two Way Switch connection.

Standard 2 Way Switch Wiring

In Standard Way of wiring, few Two Way lights Switches are connected with three-wire control. Given below is the image of the Standard way of Wiring.

"Standard

From the above diagram, the position of both COM terminals is observed and is connected together. The L1 terminal of both switches is connected to the AC supply inline form or design But the L2 terminal of the switches is attached to one side terminal of the light bulb while the other terminal is attached to the neutral AC power supply.

From the above diagram, the position of the terminal and working of wiring can be easily studied.  In the above-shown image, switches are in the default state and the light is OFF. If any of the switches are toggled then the lights turn ON.

FOR EXAMPLE:

From the above image, To turn ON the lights, COM is connected with L1 terminals. If the COM terminal of switch1 is separated or disconnected then the COM of switche1 will get connected to the L2 terminal.  After these changes, the path of the circuit will be completed and the lights will be turned ON.
Now To turn OFF the lights, both Switch and Switch 2 are Toggled and these actions cut off the flow of power to the lights. There are some possibilities in which they will turn ON. Only two possibilities are given below:
  • COM of Switch 1 is connected to L1 and COM of Switch is connected to L2.
  • COM of Switch 1 is connected to L2 and COM of Switch is connected to L1.
When comparing this setup with the Digital electronics, then this setup is similar to EX-OR Gate, as in this setup the light status (ON and OFF) is dependent on the connection of COM terminals with both L1 and L2 terminals.
The given table shows the connections of Standard Wiring and it also clearly shows the status of lights when COM terminals are connected to L1 and L2 terminals.
Switch 1 COM (connected to)
Switch 2 COM (connected to)
Status of Light
L1
L1
OFF
L1
L2
ON
L2
L1
ON
L2
L2
OFF

This method is preferred when both lines and neutral wires come from the same lighting circuit and it should be also known that this method uses more wires.

Alternative Method of Two Way Switch Wiring

This Alternative Method of Two Way Switch Wiring is the oldest one, mostly found in ancient houses ????️ and in Industrial constructions. Its also known as  Two Wire Control Wiring.
This setup of wiring is not preferred for modern constructions and if you have decided to renovate the wiring setup then the Standard Wiring method should be used instead of this one.
This setup of wiring is just an explanation for knowledge purposes and its drawbacks are also explained.
The diagram shows the Methods of implementation of Alternative Two Way Switch.

"Alternative

 

For further explanation of the diagram:

L1 and L2 terminals are linked parallel with each other in both switches then the COM terminal of the first is linked to phase while the second  COM terminals one side is attached to the light bulb while the other side is attached to neutral AC supply.

When the bulb ???? is OFF then the state of the bulb is known to be the default state. When one of the switches is moved or change the state of the bulb changes and the light turns ON. This setup is similar to EX- NOR Gate.

The given table shows the wiring method for the Alternative Two Way Switch.

Switch 1 COM (connected to)
Switch 2 COM (connected to)
Status of Light
L1
L1
ON
L1
L2
OFF
L2
L1
OFF
L2
L2
ON

This method useless wires and it’s not recommended anymore as the Phase and Neutral may come from separate lighting circuits.

Another fault in this method is the electromagnetic radiation. As we had studied that any kind of conductor produces electromagnetic radiation. Now consider the Live and neutral wires are fixed close to each other then they will cancel each other EM Radiations.

But in the Alternative Method of wiring, the Live and Neutral are implemented separately in different parts of the construction sites, making a big loop. This will obviously cause other problems such as interfering with other EM and RF signals.

Example:

Using the given products:
1: Single Pole Double Throw (SPDT)
2: Toggle Switches
3: An LED
The material that is important for a two-way switch is the SPDT. This can be used as Two Way light switch as it consists of 3 terminals and it also works similarly to a two-way switch.

The given diagram shows a casual SPDT Toggle and its terminals.

"SPDT

 

NOTE:

This example is the self-created example it’s not given anywhere. The example material is collected on the basis of their functions for making the switch and for this example Standard Way of Wiring is selected. For the first method, the 3- wire control is used with a 3.7 V Lithium-ion Battery for the power supply, and its works perfectly.

Conclusion

After reading this article you will be able to understand two-way switch wiring and its methods. For any difficulty comment down below and also tell us what’s your thoughts about this article.

About Author

Aizaz khan

Aizaz was the first person to get a byline on his blog on technology from his home in Bannu in 2017. Then, he went on to a career in breaking things professionally at my electric sparks which is where he eventually took over the kit as a hardware editor. Today, as the senior editor of hardware for my electric sparks, he spends time reporting about the most recent developments in the hardware industry and technology. If he’s not reporting on hardware or electronics, you’ll see him trying to be as remote from the world of technology as possible through camping in the wild.

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