A two way switch serves us in a variety way. It can be well used in a case of controlling a light from two different places inside a house or any place. But how can we wire a double two way switches to a light?
A number of two 2-way switches are connected in a particular way in the midst of the line wire from the source to the light. And the other terminal of the light is connected to the neutral. A correct pattern of the switching will turn on and off the light.
Let’s have a better look at the topic with more descriptions and examples…
What Is A Two-Way Switch?
A two way switch is a combination of two one way switches. There are three terminals in it; one of them is a common terminal. The other two terminals are marked as L1 and L2 in the picture below.
The schematic diagram of a two-way switch will help you to understand what is the purpose of the three terminals in practical terms:
The connector from the COM to L1 or L2 can change position according to the pressing of the switch.
What is the advantage of a two-way switch?
The advantage of a two way switch is it helps to switch an apparatus from two different locations by using a couple of such switches. Here in this article I am going to show you how it is done and the wiring system related to it.
Why do I need to use a double two-way switch?
To control a light from two different places we need a couple of two-way switches. You may think why am I not using a couple of one way switches?
Well, a couple of one way switches will serve up to a point but there will be a problem. We will have to turn on both the switches to turn on the light. That means we will have to go to both of the switches. This does not fulfill our requirement.
While a couple of two way switches relieves us from this problem. We do not need to move to both the switches to turn on or off the light. We can do it from any of the two switches.
How a double two-way switch works?
A double two way switch is at first connected to each other in the way shown in fig-3. The common port of switch-1 is connected to the line current. And the common port of switch-2 is connected to the light.
When both the switches are in the same state the light turns on. And turns off when the switches are in the opposite state.
When Does The Light Stay Off?
As said, the light stays off when the switches are in opposite state. That is, if one of the switches is off and the other is on, the light remains off.
To elaborate the matter I have marked the terminals of the switches in fig-3 as- a,b,c & d. As you can see these terminals shows the connection options of the common to L1 or L2 terminals.
From the diagram we can conclude that switch-1 & 2 are not in the same state. Because the COM terminal is connected to the L1 terminal which is marked as ‘a’ in switch-1.
But the COM terminal is connected to the L2 terminal which is marked as ‘d’ in switch-2. Thus the circuit is not completed. As a result, the light remains off as shown in Fig-3(a).
When Does The Light Turn On?
The light turns on when the switches are in same state. That is, if both the switches are onor if both the switches are on, the light turns on.
Fig-3(b) shows the ‘On state’ of the circuit. Here we can see that both the switches are in the same state.
That is, both the COM terminals are connected to the other terminals in such a way that the circuit becomes complete.
As a result current starts passing through the light.
How To Wire A Double Two Way Light Switch?
The wiring basic is similar to the schematic diagrams shown in fig-3. We need wires, a couple of two way switches and a light. Then we can wire as instructed in the previous schematic diagram.
Here we can see that the switches’ L1 terminals are connected using a blue wire. Similarly, the L2 terminals are also connected using a blue wire. The COM terminal of the switch-1 is connected to the line voltage using a red or brown wire.
Then connect the COM terminal of the switch-2 to the positive terminal of a bulb.
And finally, connect the negative portion of the light to the neutral using a black wire.
Using the color codes in the wire helps us to determine the nature of the wire through eyesight. This is a safety precaution.
How To Wire A Double Two Way Switches To Two Lights?
To add more lights into the system under the same couple of two way switches, add the lights in parallel to each other. Thus they will be controlled simultaneously by the same double switches.
To understand the situation I will modify fig-4 slightly. Just have a look at fig-5.
Is Connecting The Lights In Parallel A Tough Work?
No, it is a very simple task. Just connect the positive side of the second bulb to the positive side of the first bulb. And the negative side of the second bulb to the negative side of the first bulb.
As you can see in fig-5, the lights are parallel connected to each other to the same switch configuration, they will now turn on and off at the same time.
Where To Use This Technique?
Any place where we need to control a light from different places, you can use this technique. For example, you can use it in a long hallway or in the top and bottom side of a staircase. There you can turn on the light from either end.
Precautions That You Must Take:
While working with electricity never forget to take necessary precautions. Like-
- Turning off the main switch
- Using dry sandals
- A tester to detect live wires before touching
- Use proper color wires for live and neutral
- Do not keep the connections loose to avoid short circuits
This technique is quite an interesting idea you can see. And it is easy too. You can apply it in your home any time you want. It can be helpful to the elders of your home as well as a fun experiment for you and the young ones.
So, why are you waiting for? I am sure you are going to love it. Thank you.