Skip to content
  • There are no suggestions because the search field is empty.

How to install the LP81 Smart Relay with Switch Sense Input

This article explains the features, functions, and input settings of the Lightwave LP81 Smart Relay, including how to use its unique Switch Sense Input for integrating non-smart devices.

📦 What is the LP81 Smart Relay?

The LP81 Smart Relay shares the same size and housing as the LP82, but functions differently. Unlike the LP82, which supports Open/Stop/Close (O/S/C) control, the LP81 features a Switch Sense Input, making it ideal for integration with non-smart switches and PIR motion sensors that have a 230V switched line output.

🧠 What is Switch Sense Input?

Switch Sense Input allows you to trigger automations—within both Lightwave and third-party systems—using non-smart devices such as:

  • Traditional light switches

  • PIR motion sensors

  • Wired smoke or heat detectors

  • Legacy control systems

⚠️ Devices connected to the LP81’s input must have a 230V Switched Line Output.

💡 Key Features

  • Acts as a standard On/Off relay for non-dimmable loads up to 700W

  • Supports 6 amp circuits

  • Ideal for integrating existing infrastructure into your Lightwave system.

  • Requires a suitable housing as it is a Class II device

⚙️ Digital Input Modes in the App

The LP81 offers four configurable input modes in the Lightwave app:

  1. Switch – Suitable for PIR sensors or similar triggers

  2. Inverted Switch – Same as above, but with reversed behaviour

  3. Toggle – Designed for standard latching light switches

  4. Retractive – For momentary or multi-way switches wired in parallel

🛠️ Selecting the wrong input setting will not damage the LP81 but may prevent proper function. Always choose the setting that matches your input device.

🔌 Wiring Scenarios

There are four supported wiring configurations for the LP81 based on your installation needs. Refer to the wiring guides provided by Lightwave or contact support for detailed diagrams and recommendations.