---
title: "LG Air Conditioning (PI-485 / LGAP)"
description: "Connect LG air conditioning to TapHome via the PI-485 card and LGAP over RS485. Control split units — on/off, mode, thermostat, fan and vane."
url: "https://taphome.com/en/compatibility/lg-pi485/"
language: en
lastmod: 2026-06-05
generator: hugo
ai:
  topics: ["lg-air-conditioning","pi-485","lgap-protocol","rs485-integration","hvac-control","lgac-interface"]
  questions: ["Which LG air conditioning models are compatible with TapHome?","What is the LG PI-485 card and where do I get it?","How do I wire the PI-485 card to the LG outdoor unit?","What DIP switch settings are needed for PI-485?","How do I set the address on an LG split unit using the remote?","Why is the address different between the LG remote and TapHome?","Where do I add the LGAC interface in TapHome?"]
---

# LG Air Conditioning (PI-485 / LGAP)

Communication: RS485

- [LG PI-485 (PMNFP14A1)](https://www.lg.com)

## Integration guide

TapHome communicates directly with LG air conditioning condensers and split units over **RS485** (BUS 1, BUS 2 or BUS 3 terminal) using the LG **PI-485** communication card and the proprietary **LGAP** protocol. Multiple split units can be fully operated from TapHome with minimal additional cost.

![LG PI-485 communication card](https://taphome.com/images/compatibility/lg-pi485/lg-pi485-card_hu_a59ffe0badfcb43b.jpg)

> [!NOTE]
> LGAP is a **native TapHome interface** — there is no template to download or import. You connect the PI-485 card over RS485 and add the **LGAC** interface directly in the app (*Settings → Hardware → Add new interface → LGAC*). The PI-485 card is supplied directly by your LG dealer.

Each split unit can be controlled separately:

- On / Off
- Operation mode — Cooling, Dehumidification, Fan only, Auto, Heating
- Thermostat — setpoint and actual temperature
- Fan speed — Low, Medium, High, Auto
- Vane swing — On / Off

## Compatibility

| LG AC product line | PI-485 built in | PI-485 can be added |
|--------------------|-----------------|---------------------|
| Multi V 3 | ✓ | — |
| Multi FDX | ✗ | ✓ |
| Multi MU3 and higher (e.g. MU3M25) | ✗ | ✓ |
| Split 18 and higher | ✗ | ✓ |
| Multi MU2 (e.g. MU2M15, MU2M16, MU2M17) | ✗ | ✗ |

## Requirements

- **LG PI-485 extension card** — models PMNFP14A1 or PMNFP14A0
- 1 available TapHome Bus terminal on the TapHome Core control unit

## Wiring

### Connect the PI-485 card with the outdoor condenser unit

![LG PI-485 wiring diagram — CN_OUT to CN_CENTRAL on the ODU PCB, BUS_A/BUS_B to the central controller, DIP switch and power connections](https://taphome.com/images/compatibility/lg-pi485/lg-wiring-diagram_hu_e05987cc5248b1cf.jpg)

1. Disable power to the system
2. Connect **CN_OUT** on the PI-485 to **CN_CENTRAL** on the ODU PCB
3. Connect **BUS_A** and **BUS_B** on the PI-485 to the LG central controller or gateway
4. Select the proper DIP switch configuration: **1 and 4 ON**, all others OFF
5. Connect **CN_PWR** on the PI-485 to the outdoor unit PCB power connector
6. Restore power to the system

### Verify the PI-485 card is working

![LG PI-485 LED status indicators](https://taphome.com/images/compatibility/lg-pi485/lg-led-red_hu_7e5bfd37bee5c84f.jpg)

- **Red LED** — blinks as many times as the number of connected indoor units, then turns OFF. The cycle repeats every 3 minutes.
- **Orange and Yellow LED** — blink continuously.
- **Green RS485 LED** — blinks when the PI-485 receives data from the central controller.

For full details, see the [LG PI-485 Installation Manual](https://taphome.com/compatibility/lg-pi485/LG-PI485-Manual.pdf).

## Connect PI-485 with TapHome

One or more PI-485 cards can be connected to a TapHome BUS terminal.

> [!WARNING]
> This communication line **cannot be combined** with TapHome Bus devices or Modbus RTU devices on the same terminal. Dedicate the BUS terminal to LG communication.

![LG PI-485 to TapHome BUS terminal connection diagram](https://taphome.com/images/compatibility/lg-pi485/lg-connection-diagram_hu_147dbfc957d02967.jpg)

## Configuration

### Assigning addresses to LG split units

Turn on the indoor split unit. To set its unique identification address, use a combination of buttons on the infrared remote controller.

Remove the battery from the remote. While holding the **FAN SPEED** button, insert the battery back. Once in address configuration mode, two digits appear on the display — change the address with the **TEMPERATURE UP / DOWN** buttons and confirm with **POWER**.

> [!WARNING]
> The LG unit address on the remote is a **hexadecimal** number, while in TapHome it is **decimal**. For example, `0A` set on the LG remote becomes `10` in TapHome, and `10` on the LG remote becomes `16` in TapHome.

![Setting the LG split unit address using the infrared remote control](https://taphome.com/images/compatibility/lg-pi485/lg-remote-control_hu_9ac4d999aa47f47.jpg)

### Defining the LGAC interface in TapHome

1. Open *Settings → Hardware → TapHome Bus → Terminals* and **disable one BUS terminal** so it can be used for LG communication.
2. Go to *Settings → Hardware → Add new interface → **LGAC***.
3. Add the split units with their proper (decimal) addresses.

![Configuring the LGAC interface in TapHome](https://taphome.com/images/compatibility/lg-pi485/lg-taphome-interface_hu_2c5bb7993e113f49.jpg)