How a Light Switch Works


A light switch is a crucial electrical component for controlling lights inside and around the home. Today, there is a wide selection of light switches in the market that you can easily get both in local and online stores. While some models of light switches are simply for turning the lights on and off, others have sophisticated features that can also regulate the intensity and other specific aspects of lights. Nevertheless, the importance of light switches is undeniable.

Similar to other common electrical components, light switches can also succumb to faults from time to time. Although the best thing to do in such situations is to contact a professional electrician for assistance, there are some problems that you can easily troubleshoot and fix on your own if you understand the basics of light switches. The knowledge of how a light switch works could really come in handy whenever you are experiencing a problem with one or more light switches in your home.

Despite the simplicity in the designs of many types of light switches, there are slight disparities that you should know in order to understand how each operates.

Illustration of how the most popular light switches work.

On/Off Light Switches

These are the most popular in homes and, specifically designed to turn the lights on and off from just one location. Also called single pole or single location switches, on/off light switches have a basic design and can be operated by just anyone. The light switch only has one wire connected to it, which also makes it much easier to control and even troubleshoot during issues. The light switch has a spring that locks back and forth whenever the light switch is turned on and off to facilitate the opening and closing of the circuit.

3-Way Light Switches

Just like the On/Off switch, a 3-way light switch also has only one hot wire linked to it. However, it is a double throw, which means that if it is switched on, it changes the hot wire connection between the other two wires in the switch, known as the travellers. These are linked to another 3-way switch that transmits power to the light fixtures. If you look inside the switch carefully, you will notice that it has a ‘V’ shape with the sharp pointed end acting as the terminal that connects to the circuit breaker.

The point terminal is marked with a dark screw that also distinguishes it from the rest of the components. The other two ends of the V are connected to the traveller wires, hence their name, traveller terminals. The terminals are marked with shiny brass screws.

4-Way Light Switches

Unlike the ones above, a 4-way light switch is connected to hot wires that make it a double pole. Besides, it is also a double throw switch with two separate wires connected to the 3-way switch that transports the power to the lights. The light switch has a lot of flexibility that also allows the light fixtures to be controlled from multiple points within or outside of the building.

Although there are slight variations in the way that different types of light switches work, the design and mechanics are still the same. Light switches are quite minimalistic in design that basically entails the current flowing through the switch onto the light fixtures. Whenever the switch is flipped off, it breaks the circuit and interrupts the flow of current into light fixtures, thereby taking away their glow. Whenever the switch is flipped on, it reconnects the flow of current into the light fixtures, hence, creating the light.

A basic light switch generally has two terminals and, in some cases, a ground terminal. The hot wire that transmits power from the outlet is connected to one of those terminals. The second terminals is then, connected to the hot wire that transmits power to the light fixtures such as bulbs.

Having a Problem with your Light Switches?

In case you are experiencing any kind of issue with the light switches in your home, office or business, simply talk to Electrical Service Singapore. We provide professional electrical troubleshooting and light switches installation services Singapore. Our company can also deliver emergency electrician services at your own convenience.