By Brian McDivitt, PE

Ever since the late 1800s, electrical circuits have used simple switches to turn lights on and off. In recent decades, energy codes have been encouraging innovation to reduce the amount of energy consumed by electric lighting. With lighting controls now starting to involve new functionalities such as automatic control of plug-in receptacles, many building owners find themselves wondering: what happened to the basic switch on the wall?

The lighting controls components used in a building depend on the needs of the owner and the building’s function and size. Some components can wire into building circuit wiring, while others use low-voltage wiring for communication with light fixtures and other controls components. Recent energy codes, however, require control functions that limit the use of line voltage controls in many types of spaces. Lighting controls can also be part of a networked system, allowing a building manager to access, manage, and monitor various controls and zones throughout the building from a centralized location.

Design engineers often balance code compliance and cost implications to provide a building owner with a functional lighting controls system that is simple to use and understand. Without digging into wiring and communication methods, though, let’s look at the basic functionality of lighting control components.