Light Switches - The Heart of Your Lighting System

Light Switches - The Heart of Your Lighting System

A light switch is the heart of a home's lighting system and controls the current that powers it. They are available in a wide variety of styles, configurations and sizes to accommodate various wiring and lighting requirements. Typical light switches are single or multiple, designed for indoor or outdoor use and equipped with dimmer control features.

Light switches can be mounted in the wall and tucked into the box, or they can be surface-mounted and extended out from the wall for easier access. In either case, the wires that connect to a light switch run vertically through studs to the ceiling or horizontally through the studs from one outlet to another. Often the switches are located near outlets that are used to power lamps, fixtures and other lights.

In many cases, the switches control the current directly. However, in larger systems - such as commercial or industrial - the switches control lighting contactors that relay the current to a lower level. This enables the light switch to operate with lower amperage and smaller wires than would be required in the main lighting circuit.

Toggle switches come in a number of styles, configurations and colors. The common types include single-pole, single-throw (SPST), rotary, rocker and touch switches. They are also available in different voltages to allow for more or less electrical current. They are typically limited to simple on/off functions but some may have additional features such as dimmer controls or environmental and security protection.

Light switch design is important to consider because it impacts the user's experience and understanding of how the switch works. Visual cues, like the color of the lever and movement, are critical for users to identify the switch's state. It's also important to evaluate societal and cultural differences when choosing color for these signals.

A light switch's most visible feature is the lever that you physically move to change its position. Depending on the switch's design, it can be flat or rounded and made from materials that conduct electricity well, such as copper or silver. Inside the switch housing are metal contacts that connect or disconnect electricity. When the lever is in a certain position, the contacts are closed and electricity is allowed to flow. When the lever is in another position, the contacts are open and electricity is interrupted.

The contact terminal set screws, which hold the wires to the switch mechanism, are typically hollow and can accept up to three 1 mm (CSA) insulated wires twisted together. On some switches, a third terminal is provided for a grounding screw, which grounds the switch to protect against electrocution in the event of an electric fault. The grounding screw is usually attached to a separate copper wire that runs to a grounding rod or other suitable point in the building's electrical system. A switch that does not have a grounding screw is not considered safe for household use. It's important to check with a professional electrician before installing a switch that does not have a grounding terminal.