Electrical 101

Smart Switches

What is a Smart Switch?

A smart switch allows the switching operation to be done remotely or by preset times. Lights can be remotely turned on or off using an app on a phone or tablet. The app can also be used to turn lights on or off automatically at certain times of the day. Find Smart Switches

With few exceptions, smart switches need a neutral wire inside the switch box to work properly. Homes built before 2011 may not have a neutral wire in switch boxes.

Why Does a Smart Switch Require a Neutral Wire?

Before purchasing a smart switch, verify that the switch box it is going into contains a neutral wire.

A conventional toggle switch is a mechanical device that uses no power. It opens and closes a circuit when it is toggled. A neutral wire is not needed for proper operation.

A smart switch is an electronic device that needs power to operate and yes, most do need a neutral wire. Line and neutral supply this power.

Before 2011, neutral wires were not required in light switch boxes. The 2011 NEC update required a neutral wire to be present in all light switch boxes. This happened because switches and timers started becoming computerized and needed both line and neutral to operate properly.

Adding a Neutral Wire to a Switch Box

Adding a neutral wire to a switch box can be a major task especially for a house that is wired with NM or similar cable. 2-wire NM may need to be replaced with 3-wire NM, or an additional 2-wire NM cable. Walls might have to be opened for this installation. Patching and painting would then need to be done.

If a house is wired using conduit, it is probably easier to add a neutral wire. When there is room, a neutral wire can be added to existing conduit.

Smart Switches That Don’t Require a Neutral

It may not be worth it to add a neutral wire to an existing switch box, so the alternative would be a smart switch that does not need a neutral. Lutron has a good lineup of smart switches that don’t require a neutral. They can be found on Amazon and many home improvement stores.