A Guide on Types of Electrical Switches in the Home

Electrical switches are an essential part of any home’s electrical system, allowing you to control the flow of electricity to different areas of the house. There are several different types of switches that can be used in the home, each with its own unique characteristics and applications. In this article, we will take a closer look at these different types of switches and discuss their uses and benefits.

Types of Electrical Switches in the Home

The common types of electrical switches in the home are:

1. Single-pole switches

The basic on/off snap switch is referred to as a single-pole (SP) switch because only one contact is opened or closed at any one time. It is the most common switch in a residence and is used exclusively to turn lights on and off from one location. A single pole switch allows electrical current to flow through it in the “on,” or “make,” position and opens the connection in the “off,” or “break,” position. The most common mistake in installing a simple switch is installing it upside down, making up “off” and down “on.”

An SP switch has two terminals or screws: one terminal for the incoming hot wire and one for the wire called the “return,” which takes the power to the load when the switch is on. As far as making the circuit work, it makes no difference which wire connects to which terminal. But it is better to follow a system: Always run the incoming hot wire to the top terminal and run the wire to the load off the bottom terminal. This way, you can tell at a glance which wire runs to the switch. It also is an extremely effective troubleshooting aid.

2. Double-pole switches

A double-pole (DP) switch can turn two independent circuits on and off at once because two contacts, or poles, are opened and closed at the same time. A DP switch is wired as two independent SP switches. A DP switch is normally used to control a 240-volt appliance, such as a submersible pump or other pieces of equipment without a plug that can be disconnected for maintenance. The appliance therefore must have a cutoff switch adjacent to it or its controls to protect the person performing the maintenance.

3. Three-way switches

A three-way switch controls a load from two locations, such as at the top and bottom of a staircase or at each end of a hallway. A three-way switch has three terminals: a COM (common) terminal, and two terminals for the hot traveler wires that have no polarity (the switch has no on or off). The COM terminal is also called the “tongue,” which explains how the switch works: It laps up to connect to one traveler terminal and down to connect to the other.

4. Four-way switches

For additional point-of-load control between three-way switches, install a four-way switch. There is no limit to the number of four-way switches that can be installed, as long as they are installed between the three-way switches (a three-way switch must always be on each end of a multiple-point switching circuit). Four-way switching is used for rooms with three or more entries with switched lighting at each one.

5. Special-use switches

Switches are available for just about any switching condition that exists.

Lighted toggle switches that glow when off are perfect for dark locations or even a child’s room so the child always knows where the light switch is.

Pilot-light switches that glow when the load is turned on are very useful when a switch is at a distant location from the load.

Keyed switches are available for situations that require extra security.

Timer switches are available for temporary loads, such as bathroom fans. Programmable timer switches are available to turn on lights, a radio, or television at preset times so that people will think someone is home when the house is empty.

No matter what the use, however, most specialty switches are wired the same way and have the same two terminals that an ordinary switch has. The one thing to look out for is whether the switch is polarized, which means each wire must go to a specific screw or location on the switch. With a common snap switch, it doesn’t matter which wire goes where.

6. Dimmer switches

Dimmer switches were developed to allow more control over lighting than just on and off. As a side benefit, they also save energy and extend bulb life by reducing the amount of electricity used. Dimmer switches are available in single-pole and three-way models. High-tech electronic multilocation switches allow you to dim the lights at a number of locations from one central dimmer switch.

Single-pole dimmers only can be used for incandescent lights. Never use a dimmer to control a ceiling fan or any other motorized appliance—you’ll burn up the dimmer and the appliance. Although a table lamp will work fine, you will damage all other appliances plugged into that receptacle.