Below, you’ll learn about eight common types of wall switches and what they’re best for. Examined closely, you’ll notice that a new single-pole switch has two brass-colored screw terminals attached to the body of the switch, plus a green screw that is connected to the metal strap. In normal use, this type of switch is used to control the flow of current through “hot” wires in the circuit (usually black wires). With single-pole switch wiring, each of the brass-colored screw terminals is attached to a hot wire, and there is generally no neutral wire connection at all. The circuit’s grounding wire (usually a bare copper wire) is attached to the green grounding screw on the switch. Because 240-volt circuits operate with two individual “hot” wires, these switches have four brass-colored screw terminals to allow control of both hot wires in the circuit—the incoming wires are attached to one set of screws, and the outgoing hot wires are attached to the other set of screws. These switches are usually rated for 30 or 40 amps, rather than the 15 or 20 amps for standard single-pole wall switches. Double-pole switches also have a green grounding screw for connecting the circuit’s grounding wire. The three-way switch has three terminal screws. Depending on where the switch falls in the circuit configuration, the darkest screw terminal—marked “COM” for common—is connected either to the hot circuit wire arriving from the power source or to the hot wire that runs onward to the light fixture. The remaining pair of screw terminals are attached to “traveler” wires that link the two three-way switches together. A three-way switch also has a green grounding screw, to which the bare copper circuit grounding wire is attached. The four-way switch has four terminals plus a ground terminal. Two of the four terminals are usually brass-colored, and the other two are dark. There is no “COM” or “common” terminal, as is found on a three-way switch. The four-way switch functions as a switching device for the traveler wires between the three-way switches. While smart switches are usually simply swapped into the same location where a standard wall switch is located, most require a neutral wire connection because a small amount of current flow is necessary for their operation. Thus, it’s possible that you will require a circuit upgrade to use these switches. Other smart switches do not require a neutral connection and instead connect to the internet wirelessly through a hub. Be sure to buy a smart switch that’s compatible with your hub or voice-automation system and the lights you need to control. A rotary dimmer switch, for example, involves a knob that you rotate to increase or decrease the brightness. You press the knob to fully turn off (or on) the light. A sliding dimmer typically includes a toggle switch that turns on and off the light, along with a sliding control that turns up or down the brightness. Some dimmers have very discreet sliders that practically blend in with the rest of the switch. Single-pole switch dimmers are wired to control light brightness from only one switch. There also are dimmers available for other types of switches. The censors usually appear fairly flat and rectangular. And they have some sort of toggle to allow you to switch the light completely off, to set it to be always on, or to use it with the censor mode. The censors also have daylight detection, so they won’t turn on based on motion during the day when you don’t need supplemental light. Plus, they can be used with exhaust fans, such as in a bathroom, so you don’t have to worry about remembering to turn on and off the fan. Other switches also include an outlet to allow you an additional place to plug in electronics. Moreover, besides toggles and knobs, there are also touch switches that involve a flat touchpad that you push to control the electric current. Furthermore, some speciality switches are meant specifically for LED and CFL bulbs and often must be used if your fixture has dimmable energy-saving bulbs. Plus, there are specialty switches that can control the speed of fans, along with their light components if they have them. Standard single-pole switches, three-way switches, and four-way switches are all designed for standard 120-volt household circuits. And your choice will depend on whether you want to control a light fixture from one, two, or three or more wall locations. Double-pole switches are specialty devices that are used only when you need to control 240-volt circuits that provide power for major appliances. A smart switch can be used where you want the flexibility of automating the operation of the switch or appliance or controlling it remotely via the internet.
