Shelly 1 Gen3 – Smart Built-in Switch with Dry Contact Relay and Wi-Fi

Compact switching up to 16A with a potential-free relay

Not every switch point needs current measurement or the latest protocols. The Shelly 1 Gen3 is a proven 16A flush-mounted module with a potential-free relay (dry contact) that communicates directly with Home Assistant via Wi-Fi. Suitable for lighting, roller shutters, access control, and any other load where the load brings its own power supply. Looking for Zigbee or Matter? Then the newer Shelly 1 Gen4 is the logical step. For a smaller version without current measurement up to 8A, the Shelly 1 Mini Gen3 is available.

Power supply and connectivity

The module operates on 110–240V AC or 24–30V DC and consumes less than 1W itself. Communication takes place via Wi-Fi 802.11b/g/n (2.4 GHz) and Bluetooth 4.2. No hub, bridge, or additional gateway is required. The module has a local web interface and is accessible via HTTP API and MQTT.

Functionality and settings

The potential-free relay switches a maximum of 16A at 240V AC (or 10A at 30V DC). Because the relay is potential-free, the Shelly 1 Gen3 does not apply its own voltage to the output; the load itself determines the supply voltage. This makes the module suitable for low voltage, AC voltage, and systems such as access control or roller shutter control. Local logic and conditional switching are possible via Shelly Scripting Language.

• Resistive load: incandescent lamps, halogen, heating devices
• Capacitive load: electronic equipment with capacitors
• Inductive load with RC Snubber: LED lighting, LED drivers, air conditioning, and fans

⚠️ For inductive loads such as LED lighting and motors, the inrush current can damage the relay. Use an RC Snubber to absorb the peak current.

Expansion and accessories

The Shelly 1 Gen3 also functions as a BLE Gateway for Shelly BLU products. For a smaller version up to 8A, the Shelly 1 Mini Gen3 is available. Do you want the latest multiprotocol support with Zigbee and Matter? Then check out the Shelly collection for the Gen4 models.

Safety and reliability

The Shelly 1 Gen3 has built-in protection against overheating, overload, and overvoltage. The internal temperature sensor continuously monitors the module and can activate an automatic shutdown. The housing is suitable for installation in standard European flush-mounted boxes.

Home Assistant

The Shelly 1 Gen3 integrates directly into Home Assistant via the local Wi-Fi API. No additional hardware, add-on, or cloud connection is required. Local control via HTTP API and MQTT is confirmed.

Pairing step-by-step

• Connect the module to your 2.4 GHz Wi-Fi via the Shelly app or the local web interface
• In Home Assistant, go to Settings > Devices & services
• The Shelly will automatically appear via the built-in Shelly integration
• Click Configure and confirm; all entities are immediately available

Entities after pairing

• Switch on/off (potential-free relay)
• Module temperature in °C

Homey

The Shelly 1 Gen3 is compatible with Homey Pro via the official Shelly app for Homey. Homey Bridge does not offer local Shelly integration.

Other platforms

• Home Assistant: fully supported via local Wi-Fi API and MQTT, no cloud required
• Google Home: via Shelly Cloud
• Amazon Alexa: via Shelly Cloud
• Apple Home: not supported, no Matter on Gen3
• KNX: via KNXnet/IP

Automation examples

Example 1 – Lighting via existing wall switch and app (simple)

• Connect the Shelly 1 Gen3 in series with the existing wall switch
• Trigger: switch is pressed or time 21:00 is reached
• Action: relay on, lights turn on
• Second trigger: switch pressed again or 30-minute timeout, relay off

Example 2 – Access control with time window and notification (advanced)

• Trigger: input_button "Open door" is pressed via dashboard or Companion App
• Condition: time between 08:00 and 18:00 and presence sensor active
• Action 1: switch potential-free relay on for 2 seconds (pulse) to open electric door lock
• Action 2: send push notification: "Front door opened at [time]"
• Action 3: log the event in the HA logbook via a logbook.log service call

Points of attention

• No current measurement; use the Shelly 1PM Gen4 if energy measurement is required
• No Zigbee or Matter; use the Gen4 models from the Shelly collection for multiprotocol
• Requires a neutral wire (N); 2-wire installation is not possible
• Inductive load requires an RC Snubber to prevent relay damage
• Wi-Fi works exclusively on 2.4 GHz; 5 GHz is not supported

Box contents

• 1x Shelly 1 Gen3 module
• Quick start guide

Compatibility

Home Assistant via Wi-Fi local | Homey Pro via Shelly app | Google Home | Amazon Alexa | KNX via KNXnet/IP | Shelly Cloud optional

Specifications

Frequently asked questions

What is the difference between the Shelly 1 Gen3 and the Shelly 1 Gen4?

The Gen4 adds Zigbee and Matter to the existing Wi-Fi and Bluetooth connection of the Gen3. Both models have a potential-free relay without current measurement and the same maximum switching current of 16A. If you want the most modern protocols and future-proofing, choose the Gen4 from the Shelly collection.

What is a potential-free relay?

A potential-free relay (dry contact) does not apply its own voltage to the output. The two contacts are simply open or closed, without the Shelly itself supplying voltage. The load or system you connect determines which voltage passes through. This makes the module suitable for low voltage, AC voltage, and systems such as access control or roller shutter control.

How do I pair the Shelly 1 Gen3 with Home Assistant?

Connect the module to your 2.4 GHz Wi-Fi via the Shelly app. Home Assistant automatically detects the Shelly via the built-in Shelly integration under Settings > Devices & services. Click Configure and all entities are immediately available. More information about Home Assistant products can be found in our collection.

Does the Shelly 1 Gen3 work with Homey?

Yes, via the official Shelly app for Homey. Homey Pro is required; Homey Bridge does not offer local Shelly integration.

Is a neutral wire required?

Yes. The Shelly 1 Gen3 requires a neutral wire (N) for power supply. A 2-wire connection is not possible. Check if a neutral wire is present in your flush-mounted box before ordering. Also view the other switches in our range.

Does the Shelly 1 Gen3 support Matter or Apple Home?

No. Matter and Apple Home are not supported on the Gen3. For Matter support, the newer Shelly Gen4 line is required.

What is the difference with the Shelly 1 Mini Gen3?

The Shelly 1 Mini Gen3 is the smaller version with a maximum switching current of 8A in a more compact size. The Shelly 1 Gen3 switches up to 16A and fits in the same flush-mounted boxes but is slightly larger. Both have a potential-free relay without current measurement.

✓ slimhuisje.nl delivers the Shelly 1 Gen3 directly from stock. Proven reliable, fully local, and directly compatible with Home Assistant. Questions about wiring or the potential-free relay? Our customer service will help you further.