A switch is perhaps the most common type of electrical device, yet we know so little about it. Every room has at least one, and most of us still don’t know how to differentiate between the different types. This lack of being informed can sometimes lead to us wiring the wrong switch to a particular circuit. Truth is, most switches look the same on the outside, however it’s the way that their insides are designed that makes a switch appropriate for a certain type of job. According to this, there are four major types of electrical switches.
Single Pole Switch
This type of switch is considered to have a general purpose role. What this means is that it can be used to switch a light, receptacle or other device on or off from a single location. It is called a single pole switch because it can only control one circuit. This is the most common type of switch electrical systems in homes use. When installing such a switch make sure you wire it correctly, so that the words “on” and “off” are facing in the right direction.
Double Pole Switch
The double pole switch has an on/off function similar to the single pole to control lights or other devices from one location. But opposed to the single pole switch which consists of two brass terminals, the double pole switch has four such parts. Because of this, it can handle switching two hot wires such as the ones of a 240 volt circuit. This switch electrical wiring also comes with a ground terminal (green screw). Bottom line, the double pole switch can regulate the flow of electricity in receptacles and appliances powered by 240 volt circuits.
Three Way Switch
When there’s a need to regulate the switching of appliances from two different locations, a three way switch can be used to do so. This type of switch always comes in a pair and the on and off positions on this type of switch vary as the switch is used. It’s called a three way switch because it has three terminal screws. The “hot” wire connects to the darkest screw terminal that’s marked with “COM”. The remaining two terminals are used to connect the leads for the switch and which lead goes to what terminal makes no real difference. This switch also comes with a ground terminal (green screw). It’s important to note that in a three way application you cannot use any other type of switch besides this.
Four Way Switch
A four way switch has the unique ability to control an outlet or light from three separate locations. In order to do so, this switch has to be placed in between two three way switches. If you want to be able to regulate appliances from more than three different locations (like five for example), you’d still need to install 2 three way switches on both ends, but now you’d need 3 four-way switches in between them. Regarding outward appearance, a four way switch looks the same as a double pole with the only difference that it does not have any “on” or “off” marks.