How to Use Shelly Pro 3: Examples, Pinouts, and Specs

The Shelly Pro 3 is a versatile smart relay designed for remote control and automation of electrical devices. Manufactured by Shelly, this device features Wi-Fi connectivity and is compatible with a wide range of home automation systems, including MQTT, REST API, and popular platforms like Home Assistant. With three independent relay channels, the Shelly Pro 3 is ideal for controlling lighting, appliances, and other electrical loads in residential, commercial, or industrial environments.

• Smart home automation for lighting, fans, and appliances.
• Remote control of electrical devices via mobile apps or voice assistants.
• Integration with home automation platforms like Home Assistant or OpenHAB.
• Energy monitoring and scheduling for efficient power usage.
• Industrial automation for controlling machinery or equipment.

The Shelly Pro 3 features terminal blocks for wiring connections. Below is the pin configuration:

1. Wiring the Device:

   • Connect the live (L) and neutral (N) wires to the respective input terminals.
   • Connect the output terminals (O1, O2, O3) to the devices you want to control.
   • Optionally, connect manual switches to the input terminals (I1, I2, I3) for local control.

2. Powering On:

   • Once wired, power on the device by supplying 110-240V AC to the input terminals.

3. Connecting to Wi-Fi:

   • Download the Shelly app on your smartphone.
   • Follow the app instructions to connect the Shelly Pro 3 to your Wi-Fi network.

4. Configuring Automation:

   • Use the Shelly app or integrate the device with your preferred home automation platform.
   • Set up schedules, timers, or scenes for automated control.

• Ensure the total load on the device does not exceed 48A.
• Use appropriate circuit breakers for safety.
• Avoid exposing the device to extreme temperatures or moisture.
• For advanced users, the Shelly Pro 3 supports MQTT and REST API for custom integrations.

The Shelly Pro 3 can be controlled via MQTT, which can be integrated with an Arduino UNO using an Ethernet or Wi-Fi shield. Below is an example of Arduino code to send MQTT commands to the Shelly Pro 3:

#include <PubSubClient.h>
#include <WiFi.h>

// Wi-Fi credentials
const char* ssid = "YourWiFiSSID";
const char* password = "YourWiFiPassword";

// MQTT broker details
const char* mqtt_server = "192.168.1.100"; // Replace with your MQTT broker IP
const int mqtt_port = 1883;
const char* mqtt_user = "mqtt_user";       // Replace with your MQTT username
const char* mqtt_password = "mqtt_pass";  // Replace with your MQTT password

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
  Serial.begin(115200);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");

  // Connect to MQTT broker
  client.setServer(mqtt_server, mqtt_port);
  while (!client.connected()) {
    if (client.connect("ArduinoClient", mqtt_user, mqtt_password)) {
      Serial.println("Connected to MQTT broker");
    } else {
      Serial.print("Failed to connect, rc=");
      Serial.print(client.state());
      delay(2000);
    }
  }
}

void loop() {
  // Example: Turn on Channel 1 of Shelly Pro 3
  if (client.connected()) {
    client.publish("shellypro3/relay/0/command", "on");
    delay(5000); // Wait 5 seconds
    client.publish("shellypro3/relay/0/command", "off");
    delay(5000); // Wait 5 seconds
  }
}

1. Device Not Connecting to Wi-Fi:

   • Ensure the Wi-Fi network is 2.4 GHz (Shelly Pro 3 does not support 5 GHz).
   • Check that the Wi-Fi credentials are entered correctly in the Shelly app.

2. Relay Channels Not Responding:

   • Verify the wiring connections and ensure the load does not exceed the rated capacity.
   • Check the Shelly app or automation platform for proper configuration.

3. Device Overheating:

   • Ensure the device is installed in a well-ventilated area.
   • Avoid exceeding the maximum load per channel or total device load.

4. MQTT Commands Not Working:

   • Verify the MQTT broker IP, port, username, and password.
   • Ensure the Shelly Pro 3 is configured to use MQTT in its settings.

• Can the Shelly Pro 3 be used outdoors?

  • No, the Shelly Pro 3 is designed for indoor use only. Use a weatherproof enclosure if outdoor installation is required.

• Does the Shelly Pro 3 support dimming?

  • No, the Shelly Pro 3 is a relay switch and does not support dimming functionality.

• Can I control the Shelly Pro 3 without the internet?

  • Yes, the device can be controlled locally via its web interface or local MQTT server.

• Is the Shelly Pro 3 compatible with voice assistants?

  • Yes, it is compatible with Google Assistant and Amazon Alexa.

This concludes the documentation for the Shelly Pro 3. For further assistance, refer to the official Shelly support resources.