Common Wiring and Compatibility Questions for Kasa Smart Ceiling Fan Controller and Dimmer Switches

Before installing your Kasa Smart Ceiling Fan Control and Dimmer Switch, you may have some questions about compatibility with your home’s wiring or third-party automation support. Please refer to the common questions and answers in this guide for more information.

Q1: What should I do if I replace two separate old switches (fan switch and light switch) with a KS240, but each one has its Line wire?

Please check the Ground Fault Circuit Interrupter (GFCI) first.

• If there is no GFCI installed for the fan and light circuits, or there is a single GFCI protecting both the fan and light circuits, then only one Line wire needs to be connected to KS240. Cover the extra Line wire with a wire nut or wrap it with insulating tape for safety. You can follow the instructions in the provided Quick Start Guide to wire your KS240.

• If both fan and light circuits have their own GFCIs, incorrect wiring will cause improper GFCI operation. It is recommended that you consult an electrician for wiring assistance.

Note: Whether there is a GFCI for the fan and light circuits, if two Line wires are available, only one is needed to connect to KS240. Please cover the extra Line wire with a wire nut or wrap it with insulating tape for safety.

Q2: How do I identify the Line and Load wires if I replace a single fan and dimmer switch with KS240 and there is more than one energized wire?

Follow the instructions below to identify the energized wire:

Note:

• The product should be installed by a qualified electrician.
• Take the necessary precautions to avoid electric shock.
• For your safety, you can place a warning label on the circuit breaker. For example: "Caution: Circuit in Operation. DO NOT Operate Circuit Breaker!"

1. Adjust the ceiling fan and light brightness to the highest levels. Turn off the circuit breaker and turn it back on. The light and fan should work properly.

2. Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off.

3. Disconnect one of the energized wires. Wrap the exposed portion of the wire and the terminals with insulating tape.

4. Turn on the circuit breaker and check if the light and fan work.

If the fan doesn’t work and the light does not illuminate, then the disconnected wire is the Line wire:

1) Turn off the circuit breaker and use a voltage detector to test terminals and other metal parts of the old switch to confirm that all power is off. Label the Line wire, and then connect the Line wire to the old switch.

2) Disconnect another energized wire and wrap the nude part of the wire and the terminals with insulating tape. Then turn on the circuit breaker.

• If the fan doesn’t work but the light illuminates, the disconnected wire is the Fan Load wire. The remaining wire is the Lighting Load wire.

• If the fan starts spinning but the light does not illuminate, the disconnected wire is the Lighting Load wire. The remaining wire is the Fan Load wire.

3) Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off. Label the Fan Load and Lighting Load wires.

If the fan starts spinning but the light does not illuminate, the disconnected wire is the Lighting Load wire:

1) Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off. Label the Lighting Load wire and then connect the Lighting Load wire to the old switch.

2) Disconnect another energized wire and wrap the nude part of the wire and the terminals with insulating tape. Then turn on the circuit breaker.

• If the fan doesn’t work and the light does not illuminate, then the disconnected wire is the Line wire. The remaining wire is the Fan Load wire.

• If the fan doesn’t work but the light turns on, the disconnected wire is the Fan Load wire. The remaining wire is the Line wire.

3) Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off. Label the Fan Load and Line wires.

If the fan doesn’t work but the light illuminates, the disconnected wire is the Fan Load wire:

1) Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off. Label the Fan Load wire and then connect the Fan Load wire to the old switch.

2) Disconnect another energized wire and wrap the nude part of the wire and the terminals with insulating tape. Then turn on the circuit breaker.

• If the fan doesn’t work and the light does not illuminate, then the disconnected wire is the Line wire. The remaining wire is the Lighting Load wire.

• If the fan starts spinning but the light does not illuminate, then the disconnected wire is the Lighting Load wire. The remaining wire is the Line wire.

3) Turn off the circuit breaker and use a voltage detector to test the terminals and other metal parts of the old switch to confirm that all power is off. Label the Lighting Load and Line wires.

Q3: Does KS240 work with third parties?

Yes. However, third parties vary in supporting certain fan and dimmer functions. Please check the table below for details.

*"Turn on/off" indicates toggling the device's state. For example: if it's on, it can be turned off, and if it's off, it can be turned on.