Electrical – motion sensor light with a three way switch

electrical

I want to put a motion sensor light in my breezeway. Right now the light is controlled by a three way switch. Will I ab able to do this installation.

Best Answer

Sure. The three way just allows two switches to turn a light on and off. The motion sensor limits the controlled light, if it is set to go on, only when it senses motion.

Effectively, the three way switches prime the light to go on and the motion triggers it. The switches determine if there is power to the light socket. The motion detector (which controls power after the switches) then either turns the light on or off based on motion.

The problem is that it will be difficult to determine when the light is primed to go on. Regular switches (single pole, one way) are on when up and off when down. However, for three ways, up on a given switch an be on or off depending on the orientation of the other switch.

How do you know if the motion sensor controlled device is ready to go? If you can see both three way switches at the same time, a practical way to do this is to set up the switches so that they are on when both are up or down and off when they are not in the same position.

UPDATE: If you can't see both switches at the same time, you cannot know the motion controlled device is ready (ON) unless you set up some sort of pilot light. There are three way switches that are illuminated when off, such as this one.

illum switch 3way

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