How to install your Tapo Smart Wi-Fi Light Switch, 3-Way Kit (Tapo S515D KIT)

This article provides detailed instructions on how to wire the Tapo Smart Wi-Fi Light Switch, 3-Way Kit.

Wiring Diagram

Before You Start

• The main and satellite dimmers cannot work separately or with traditional 3-way switches.
• The main and satellite dimmers are different and should be installed in the correct wall boxes.
• Tools You’ll Need

• Get to Know the Wires

The wire colors used in this guide are recommended by the National Electric Code (NEC). Your actual wire colors may vary.

Line (Live/Hot): Usually black. One end is connected to the circuit breaker, the other to your FIRST 3-Way switch.

Load: Usually black. One end is connected to the light fixture, the other to your SECOND 3-Way switch.

Travelers: Usually one is black and the other is red. The two terminals are opposite each other with the same color screws.

Neutral: Usually a bundle of white wires and not connected to the dumb switch. They may be folded up in the very back.

Ground: Usually green or copper.

Note: If you are unsure, consult a qualified electrician.

1. Pull out the old switches.

Turn off the circuit breaker. Remove the wall plate of the two old switches and pull the switches out. Your dumb switches might look like this:

2. Label the Traveler wires in the two wall boxes.

3. Identify the Line/Load wires.

1) Disconnect the Line/Load wires from the two switches, and cover them with the provided wire nuts for safety.

2) Turn on the circuit breaker. Use a voltage detector to identify the energized wire (Line wire). The other will be the Load wire.

3) Turn off the circuit breaker and label the Line wire. This is the wall box for the main dimmer. Label the other wire in the other wall box as the Load wire. This is the wall box for the satellite dimmer.

Note: If your Line and Load wires are in the same wall box, just label the wires and follow the wiring guide below.

4. Label the Neutral wire in the wall box for the main dimmer, and the Ground wires in both wall boxes.

5. Disconnect wires from the old switch and connect them to the Tapo smart switch as below.

• If the Line and Load wires are in separate wall boxes

No need to distinguish between the two Traveler wires.

• If the Line and Load wires are in the same wall box

1) The Satellite’s load wire should be capped with a wire nut for safety and left unused.

2) Identify the color of the Satellite’s Traveler wire near its Load wire. Connect the Traveler wire of the same color from the main's wall box to either Traveler terminal. Then, connect the Load wire from the wall box to the same terminal.

6. Line up the dimmer switch with the mounting holes and secure it with screws. Ensure the UP arrow on the back of the wallplate points up and attach the wallplate. Then turn on the circuit breaker.