How to connect Shelly PRO 3EM energy meter with Reduxi controller
Connect your Shelly Pro 3EM to the Reduxi Controller via Modbus TCP.
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Product photo of a narrow white-lilac DIN-rail module on a white background, seen slightly from above. Two green screw-terminal blocks at the top, each with two screws, at different heights. Front: LED labels 'Power', 'Wi-Fi', 'LAN', 'Count', the 'Shelly' logo and a 'Reset' label at the bottom. A line wiring diagram is printed on the housing and side: labelled blocks such as C, N, A, B, 1A, 1B, 1C, TA, TB, TC, TN with current-transformer symbols. Black connector terminals are visible at the bottom.
1 Technical documentation
Instructions for connecting and configuring the device are on the manufacturer web page.
- Shelly Pro 3EM: knowledge base – Technical data, documents and connection instructions
- Shelly Pro 3EM: web interface guide – Wi-Fi, Ethernet and static IP settings
- Shelly Pro 3EM: user and safety guide (PDF) – Multilingual printed guide
- Shelly API: Modbus component – Enable Modbus TCP and register description
- Shelly 3EM: knowledge base – Link from the previous version of this article (older Shelly 3EM model)
2 Required equipment
You need the following components:
- Reduxi Controller
- Shelly Pro 3EM (SPEM-003CEBEU), Pro 3EM-3CT63 (SPEM-003CEBEU63) or Pro 3EM-400 (SPEM-003CEBEU400)
- Current transformers: 3 for the phases, 1 optional for the neutral conductor (CT 120 A is compatible)
- Ethernet cable (for the wired connection) or local Wi-Fi network (802.11 b/g/n)
- Smart device (phone, computer or tablet) to configure the Shelly
- Laptop or tablet with internet access to configure the device in Reduxi
3 Prepare the Shelly Pro 3EM
3.1 Technical data
3.2 Connect the Shelly to your local network
Wi-Fi: press and hold the button for 5 seconds. This activates the access point of the device. The network name has the format ShellyPro3EM-XXXXXX. Connect your smart device to it and open the web interface of the Shelly.
In the web interface, go to Settings > Wi-Fi. Enter the name and password of your network or set a static IP address there. After saving, a link with the new IP address of the device appears above the Wi-Fi settings.
Ethernet: connect the RJ45 cable only when the device is powered off. In the web interface, go to Settings > Network settings > Ethernet and enable the Ethernet connection. For a static IP, enable that option and enter IP address, DNS server, gateway and network mask.
3.3 Enable Modbus TCP
Reduxi reads the Shelly Pro 3EM via Modbus TCP. The Modbus TCP port of Shelly devices is 502. Enable Modbus with the RPC method Modbus.SetConfig. Replace IP with the IP address of the Shelly:
http://IP/rpc/Modbus.SetConfig?config={"enable":true}
A successful call returns {"restart_required": false}. You can check the setting with Modbus.GetConfig or Modbus.GetStatus.
4 Log in to the Reduxi web interface
You can open the Reduxi web interface in two ways:
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Screenshot of three Reduxi mobile app screens side by side, with cyan boxes and number badges 2 to 4. Left screen (dashboard, dark theme): menu icon at top left marked with a box and badge 2; 'reduxi' logo; tabs 'Real time data' (active) and 'Statistics'; price 5.79 € and temperature 3.2 °C; energy flow diagram with a house in the centre (-1.25 kW) and icons with values 69.0 W, 1.3 kW, 1.1 kW (red ring), -165.0 W with 97 % (red ring) and 0.0 W values at the bottom; tabs 'Power' and 'Energy'; bottom navigation: Dashboard, Diagnostics, Device control, Settings. Middle screen (side menu): 'reduxi' logo, 'Number of locations: 1233', heading 'Reduxi device management', entries '+ Add Reduxi location' and 'Reduxi devices' (marked with a box and badge 3), then 'My profile' and 'About app'. Right screen (device page): Back; picture of a black Reduxi controller with two Ethernet ports; status 'Connected'; card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'; card 'Connect to configurator': 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' with button 'Activate tunnel connection' (marked with a box and badge 4); card 'Unit details' with field 'Unit ID'.
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Screenshot made of two parts side by side. Left part: Reduxi mobile app screen on a dark background. Top: Back button; picture of a black Reduxi controller with two Ethernet ports and a terminal block; status 'Connected' with a Wi-Fi icon. Card 'Update available': 'New update is available for your Reduxi device.' with button 'Download and install update'. Card 'Connect to configurator' with a key icon: 'Tunnel connection enables remote access to your Reduxi configurator, without need to be connected to the same local network.' and button 'Open configurator', marked with a cyan box and number badge 5. Below: card 'Unit details' with a field 'Unit ID' (value not visible). Right part: Reduxi Configurator opened in a browser, marked with a cyan frame and number badge 6. Header: back arrow, 'Tunnel connection', reload icon. Left sidebar with icons (lightning, chip, lightning bolt, bar chart, gear). Page 'Home' with a green link icon. Green notice: 'New patch available. Click here to apply.' with a close X. Time 09:12:56. Energy flow diagram with a house in the centre (1.700 kW) and icons for grid (0.000 kW), solar (1.700 kW), battery (green, 0.000 kW and 0.800 kW), a device at left (0.900 kW), electric vehicle and a charger or device at bottom. Label 'Energy manager' at the bottom.
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)Text description of this image
Screenshot of the Reduxi Configurator login page in a Chrome browser window. The address bar shows 'Not secure' and 'reduxi.local'; the address bar is marked with a cyan box and an enlarged copy of it (cyan box, text 'Not secure reduxi.local') is shown at the left, connected by a cyan line. Page background: light grey line drawing of a house with solar panels (green), a wall box, an inverter, a car and a charger. Top left: 'reduxi configurator' logo. Login box in the centre with title 'Login', a language selector (English flag, 'English'), a username field and a password field, and a dark 'Login' button.
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Screenshot of the Reduxi Configurator web interface after login, light theme. Top left: 'reduxi configurator' logo. Header bar: 'Home' at left, green 'Connected' status at top right. Left sidebar: expanded section 'Devices' with a list of entries, then collapsed sections 'Manager' and 'Configuration' and 'Settings'. Main area: energy flow diagram. House in the centre with ring, value 24.20 kW. Grid icon at top left, 24.20 kW (red dot on its line). Solar icon at top right, value '-'. Left icon (battery or device), 6.700 kW (green dot on its line). Right icons (battery storage and a device), values '-'. EV charger icon at bottom left, 31.00 kW. A further device icon at bottom right. Label 'Energy manager' below the house.
5 Add the Shelly Pro 3EM to Reduxi
Use these steps to add a new Shelly Pro 3EM or to edit an existing one.
5.1 Basic settings
Log in locally to the Reduxi Configurator on the controller (see Point 4) and press the Add device button. In the first step, enter the basic settings of the device: select the energy meter and the Shelly Pro 3EM, and enter a name of your choice. Then press Next.
5.2 Communication settings
Select the communication channel. Enter the connection details of the Shelly Pro 3EM:
| Parameter | Value |
|---|---|
| Connection | TCP/IP (Modbus TCP) |
| IP | The IP address of the Shelly in your local network (see Point 3) |
| Port |
502 (Modbus TCP port of Shelly devices) |
Then enter and choose the advanced settings.
5.3 Test communication
Click Test communication at the bottom of the wizard. It reads the Shelly Pro 3EM once and saves nothing. If the test succeeds, click Done: only Done creates the device.
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Screenshot of the bottom button bar of a Reduxi Configurator page. Left: button 'Back'. Right: button 'Test communication' (marked with a cyan box) and dark button 'Done'.
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Screenshot of the Reduxi Configurator page 'Communication channel and device configuration'. Connection *: TCP/IP (dropdown). IP *: 192.168.50.243, with button 'Scan for IP'. Port *: 502, with button 'Test port'. Modbus unit ID *: 1. Buttons at the bottom: Back (left), Test communication and Done (right). The Done button is marked with a cyan box.
6 Check the readings
6.1 Last measurements
After communication is established, check the values under Devices – Shelly Pro 3EM in the Reduxi Configurator as an additional test.
✓ Summary
Preparation (Points 1–2): Open the Shelly documentation and prepare the equipment.
Shelly Pro 3EM (Point 3): Connect the Shelly to your network, set a static IP and enable Modbus TCP.
Add to Reduxi (Points 4–5): Log in to the Reduxi Configurator, add the device with the Shelly IP and port 502 and test the communication.
Go live (Point 6): Check the last measurements under Devices.
→ Common issues
| Issue | Solution |
|---|---|
| Test communication fails | Check that Modbus TCP is enabled on the Shelly (Modbus.GetStatus) and that IP and port 502 in the Reduxi Configurator match the Shelly. |
| The Shelly IP address changed | Set a static IP address on the Shelly under Settings, then enter the new IP in the Reduxi Configurator. |
| 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. |