Shelly 1 Gen4 | Smart built-in switch with potential-free relay, Wi-Fi, Zigbee and Matter

Compact switching up to 16A with potential-free relay

Not every switching point needs power metering. The Shelly 1 Gen4 offers everything the 1PM Gen4 does (multiprotocol, compact, fully local) but without energy metering and with a potential-free relay (dry contact). This makes it suitable for circuits where the load provides its own supply voltage, such as motors, roller shutters, access control, or industrial equipment. Do you also want to measure consumption? Then consider the Shelly 1PM Gen4.

Power and connectivity

The module operates on 110–240V AC or 24–30V DC and consumes less than 1.2W itself. Communication occurs via Wi-Fi 802.11b/g/n (2.4 GHz), Zigbee, Bluetooth 4.2 with BLE, or Matter over Wi-Fi. Zigbee and Wi-Fi modes are not simultaneously active; you choose one protocol per installation.

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 Gen4 does not supply its own voltage to the output; the load determines the supply voltage itself. This makes the module flexible for both low-voltage and AC applications. Advanced 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

⚠️ With 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 Gen4 functions as a BLE Gateway for Shelly BLU products and as a Wi-Fi repeater for other Shelly IoT devices. Do you want the same module with power metering? Then the Shelly 1PM Gen4 is the direct choice. For a smaller version without power metering up to 8A, the Shelly 1 Mini Gen4 is available. View the full range in the Shelly collection.

Safety and reliability

The Shelly 1 Gen4 has built-in protection against overheating, overload, and overvoltage. The internal temperature sensor continuously monitors the module and can trigger an automatic shutdown. The casing is suitable for installation in standard European wall boxes.

Home Assistant

The Shelly 1 Gen4 integrates with Home Assistant via Wi-Fi (local API), Zigbee (ZHA or Zigbee2MQTT), or Matter. All three methods work completely locally without a cloud connection.

Method 1 – Direct Wi-Fi integration (recommended, no hub)

• 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 appear automatically via the Shelly integration or via local API or MQTT
• All entities are immediately available without an add-on or additional hardware

Method 2 – Zigbee via ZHA or Zigbee2MQTT

• Enable Zigbee mode via the Shelly app or web interface
• Add the device as a Zigbee end device in ZHA or Zigbee2MQTT
• Pair via your existing Zigbee USB controller

Method 3 – Matter over Wi-Fi

• Activate Matter mode in the Shelly app
• Add via the Matter integration in Home Assistant under Settings > Devices & services
• Scan the Matter QR code or enter the pairing code

Entities after pairing via Wi-Fi

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

Homey

The Shelly 1 Gen4 is compatible with Homey Pro via the official Shelly app for Homey. Via Matter, the module can also be used with Homey Pro (2023). Homey Bridge does not offer local Shelly integration.

Other platforms

• Apple Home: via Matter over Wi-Fi
• Google Home: via Matter or Shelly Cloud
• Amazon Alexa: via Shelly Cloud or Matter
• Samsung SmartThings: via Matter
• KNX: via KNXnet/IP communication

Automation examples

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

• Connect the Shelly 1 Gen4 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 [timestamp]"
• Action 3: log the event in the HA logbook via a logbook.log service call

Points of attention

• No power metering; use the Shelly 1PM Gen4 if energy metering is required
• Requires a neutral wire (N); 2-wire installation is not possible
• Inductive loads (LED drivers, motors) require an RC Snubber to prevent relay damage
• Wi-Fi works exclusively on 2.4 GHz; 5 GHz is not supported
• Zigbee mode and Wi-Fi mode are not simultaneously active; choose one protocol per installation
• Activating Matter requires an active Wi-Fi connection; Matter over Thread is not supported

Box contents

• 1x Shelly 1 Gen4 module (blue)
• Quick start guide

Compatibility

Home Assistant via Wi-Fi locally, Zigbee (ZHA and Zigbee2MQTT) and Matter | Homey Pro | Apple Home | Google Home | Amazon Alexa | Samsung SmartThings | KNX via KNXnet/IP | Shelly Cloud optional

Specifications

Frequently asked questions

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

The main difference is power metering. The Shelly 1 Gen4 has a potential-free relay but does not measure power or energy consumption. The Shelly 1PM Gen4 offers the same switching function AND measures watts, amperes, volts, and kilowatt-hours in real time. Both models have the same size and protocols.

What is a potential-free relay?

A potential-free relay (dry contact) does not supply 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 what voltage passes through. This makes the module suitable for low-voltage, AC, and systems such as access control, roller shutter control, or integration with other equipment.

How do I connect the Shelly 1 Gen4 to 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. Do you want to connect via Zigbee? Enable Zigbee mode and add the device to ZHA or Zigbee2MQTT via your Zigbee USB controller.

Do I need a hub?

Via Wi-Fi, the module communicates directly with Home Assistant via the local API; no hub is required. Via Zigbee, you need a Zigbee coordinator, such as a Zigbee USB controller.

Can I use Zigbee and Wi-Fi simultaneously?

No. You choose one mode during installation: Wi-Fi, Zigbee, or Matter. Switching is possible via the web interface or the Shelly app.

Is a neutral wire required?

Yes. The Shelly 1 Gen4 requires a neutral wire (N) for power supply. A 2-wire connection is not possible. Check if a neutral wire is present in your wall box before ordering. Also, view the other switches in our range.

Does the Shelly 1 Gen4 work with Apple Home?

Yes, via Matter over Wi-Fi. Activate Matter mode in the Shelly app and add the device via Matter in Apple Home. An Apple Home Hub (HomePod or Apple TV) is required for remote automations.

✅ slimhuisje.nl supplies the Shelly 1 Gen4 directly from stock. Smartly switch any load using the protocol that suits your installation. Questions about the potential-free relay or wiring? Our customer service will help you further.