In a four-location lighting control setup, which configuration of switches is used?

• A. Two three-way and two four-way
• B. Two four-way and two three-way
• C. One three-way and three four-way
• D. Three four-way and one three-way

Answer: (A)

Four-location control uses a mix of three-way and four-way switches. At the two ends of the run you place three-way switches; they have a common terminal that connects to the feed or the load and two traveler terminals that run between switches. Between those ends go four-way switches, each with four terminals that simply swap which traveler wires are connected depending on its position. This arrangement lets any one switch change the light’s state from any location because the traveler paths stay connected through the chain of switches. For four locations, the standard and correct setup is two three-way switches and two four-way switches.