Reduxi with Growatt String Inverter
Integrate the Growatt MAX 100-150KTL3-X string inverter with the Reduxi Controller via Modbus RTU. This gives you maximum flexibility and lower energy costs.
1 Preparation
1.1 Technical documentation
The Growatt website lists all Growatt inverters and installation guides. The user manual of the Growatt MAX 100-150KTL3-X is an example of an installation guide.
- Growatt products – Full list of Growatt inverters and installation guides
- Growatt MAX 100-150KTL3-X LV/MV user manual (EN, 2025-07) – Installation guide for the Growatt MAX 100-150KTL3-X
- Growatt MAX 100-150KTL3-X LV product page – Product page with current manuals and quick guide
1.2 Required equipment
- Reduxi Controller
- Growatt MAX 100-150KTL3-X string inverter
- Twisted-pair shielded cable for the RS-485 communication line (recommended)
- Laptop or tablet with internet access to configure the device in Reduxi
2 Connect the inverter to the Reduxi Controller via RS-485 Modbus RTU
Modbus RTU is used to access the interface of the string inverter. You must therefore make a physical connection.
2.1 Find the RS-485 connector on the inverter
The Modbus communication connectors are on the bottom of the inverter. The RS-485 connector is at location H in the picture (bottom view of the terminals).
2.2 Connection of a single inverter
- Use twisted-pair shielded wire for the RS-485 communication line (recommended).
- For single-machine communication, connect the communication line to pin 3/4 and its shielding layer to pin 1.
- The figure shows the RS-485 terminal types: terminal type 1 and terminal type 2.
Connect the inverter to the Port 1 or Port 2 interface of the Reduxi Controller. In the picture, 485-1 A1 connects to A+ (Port 1) and 485-1 B1 connects to B- (Port 1).
| Growatt inverter | Reduxi Controller |
|---|---|
| 485-1 A1 | A+ (Port 1) |
| 485-1 B1 | B- (Port 1) |
2.3 Connection of multiple inverters in parallel
- Use twisted-pair shielded wire for the RS-485 communication line (recommended).
- Link RS485 OUT (pin 5 = A, pin 6 = B) of the first inverter to RS485 IN (pin 3 = A, pin 4 = B) of the next inverter.
- Repeat the daisy-chain connection for all additional inverters (A to A, B to B).
- Enable the termination resistor (pins 15/16) on the last inverter in the chain.
3 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
http://reduxi.local. You can find the controller's IP address in your router's device list or in the Reduxi app under Reduxi devices.admin · Password: admin (factory default)4 Add the inverter to Reduxi
Use these steps to add a new inverter or to edit an existing one.
4.1 Basic settings
Log in locally to the Reduxi Configurator on the controller (see Point 3) and click + Add device.
In the first step (basic settings), select the basic parameters of the device:
- Device type:
Hybrid inverter - Type:
Growatt - Name: a name of your choice
4.2 Communication settings
The second step sets up the communication channel between the Reduxi Controller and the Growatt string inverter. These settings are for RS-485 Modbus RTU. Define these fields:
| Parameter | Value |
|---|---|
| Modbus Unit ID | Modbus unit ID of the inverter |
| Inverter Type | Select the inverter type |
| Battery Type | Select the battery type |
4.3 Test communication
Click Test communication at the bottom of the wizard. It reads the Growatt string inverter once and saves nothing. If the test succeeds, click Done: only Done creates the device.
5 Check the readings
5.1 Last measurements
After communication is established, check the values under Devices – Growatt in the Reduxi Configurator as an additional test.
5.2 Enable control by Reduxi
To integrate the inverter into the Reduxi strategy, set the control type under Devices – Growatt to AUTO. Only then do strategy commands affect the inverter.
To achieve maximum flexibility and energy cost reduction with dynamic prices and dynamic tariffs, define a strategy as described in Strategies for Reduxi controller.
✓ Summary
Preparation (Points 1–2): Use the Growatt documentation. Connect the RS-485 line from port 485-1 of the inverter to Port 1 or Port 2 of the Reduxi Controller (A1 to A+, B1 to B-).
Growatt inverter (Point 2): For several inverters, daisy-chain RS485 OUT to RS485 IN and enable the termination resistor (pins 15/16) on the last inverter.
Add to Reduxi (Points 3–4): Log in to the Reduxi web interface. Add the device, set Modbus Unit ID, Inverter Type and Battery Type, and run Test communication.
Go live (Point 5): Check the readings. Set the control type to AUTO and define a strategy.
→ Common issues
| Issue | Solution |
|---|---|
| Test communication fails | Check the RS-485 wiring: 485-1 A1 to A+ and 485-1 B1 to B- on Port 1 of the Reduxi Controller. Check the Modbus Unit ID. |
| Several inverters do not respond | Check the daisy chain (RS485 OUT to RS485 IN, A to A, B to B). Enable the termination resistor (pins 15/16) on the last inverter. |
| Open configurator does not open or stays empty | The tunnel is not active yet. Wait about 30 seconds and check that the controller is online. |
Login with admin is rejected |
The password was changed during installation. Ask the installer. The Reduxi account password does not work here. |
reduxi.local does not load |
Your device is not in the same network as the controller. Use the IP address or the tunnel connection. |
| Communication test fails, device shows offline | Check reachability, IP address / port / unit ID, and that the protocol is enabled on the device. |