Smart Switch Installation – Line Wire vs Load Wire – Neutral vs Ground Wire – Find Neutral Wire

by Harlan Yee on May 27th, 2020

Installing a hard wired smart switch or any wall switch can be intimidating. But in this tutorial I’ll take the mystery out of it so you can start building the smart home you’ve always wanted. The wiring requirements are all the same on any smart switch. There’s going to be a load, neutral and line wires in addition to the ground. There’s 4 wires total and it’s the same with the Teckin smart switch that I’m installing in this video.

But before starting, I’ll turn off the breaker for the room I’m working in. This tutorial is based on a single pole switch. That means there is only one switch that turns on the room light. There are no other switches that control this light fixture. To help with the installation I’m going to use the voltage tester to find the line wire. The line wire comes from the breaker box so it should have power when I hold the tester next to it. The load wire sends power to the light itself so it shouldn’t have power when the switch is off. But I can tell when power goes through it when I turn on the light. After I’ve identified the line and load I can start the installation. Just connect the corresponding wires together with the new switch.

Again I’ll turn off the breaker before doing any work. And it’s a good idea to do one more check to make sure the power is off at the switch. When there’s no power start by removing the wire nut on the line wire. Now take the black line wire from my smart switch and tie these together. And don’t worry, the rest of the installation is going to be very easy. Next disconnect the load wire. Remember that this is the one that sends power to the light fixture when the switch is on. And for those of you who have never worked with wire nuts, they have screw threads inside that grab and hold the wires together. Just make sure the wires are lined up and twist until tight. The ground wire is easy to identify because it’s usually a bare copper wire.  The last and most important is the neutral wire. It’s required on all smart switches and it’s usually several white wires bundled together. The reason why a neutral wire is required is because it provides constant power to the transmitter and receiver in the switch for wireless communication. Depending on the age of your home, you may or may not have a neutral wire. If not you’ll have to talk to an electrician about your options.

Once all the wires are connected turn the power back on to this switch location. If the LEDs are lit up the switch is fully functional! But before stuffing the wires back in the wall box, turn off the breaker once more. You don’t want any power going through these wires when putting them back into the wall box.  This is going to be a tight squeeze in the box with all the wiring and the body of the smart switch. But when it’s all in the switch can be attached to the wall. And one last thing, I couldn’t have done this installation without a voltage tester. The one I bought was only $15 and well worth it for DIY electrical projects! Last thing I added was a Lutron Claro Decora Wall Plate for a clean finished look. If this video was helpful please give me a thumbs up and hit the subscribe button to stay up to date on all my weekly videos!

Products used in this post:

Tacklife Voltage Tester VT-02

Teckin Smart Dimmer Switch

Lutron Claro Decora Wallplate

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