What’s the Difference Between a 1-Way, 2-Way, 3-Way, and 4-Way Switch? Why Do People Call Them Different Names?

Many people have probably heard different ways to refer to electrical switches and may be wondering which term is actually correct. Some people even use different names for the same type of switch. This confusion arises because the UK and the US have different ways of naming switches, which is the main reason for the misunderstanding.

Let’s take a look at how to properly identify and name the switches:

1-Way Switch (with 2 terminals)
This is the simplest switch, as it is used to turn a single circuit on or off from just one switch.

2-Way or 3-Way Switch (with 3 terminals)

If referred to in the UK, this is called a 2-way switch, but in the US, it’s called a 3-way switch. Since most of the switches used in Thailand are of the US type, electricians typically refer to it as a 3-way switch. This switch is commonly installed at stairs in two-story houses because it usually requires two switches (which can be located in different places) to control a single circuit.

3-Way Switch or 4-Way Switch (with 4-6 terminals)

In the UK, this switch is called a 3-way switch, but in the US, it’s referred to as a 4-way switch. This type of switch can be used to control a single circuit with more than two switches (sometimes referred to as a “cross switch”).