Shelly
Shelly Pro 3EM
- Native integration
- Local control
- Wi-Fi
- Bluetooth
- Ethernet
Prices verified October 2026
See more smart plugs & energy picks on our Amazon storefront →Our verdict
A three-phase DIN-rail energy meter with three clamp CTs, and the one to buy for whole-home monitoring if you have a three-phase supply or want per-phase readings; on single-phase UK homes it still works, you simply use one clamp, though a single-phase Shelly EM is cheaper. It needs mounting in the consumer unit, so it is an electrician job or at least confident-DIY with the supply isolated. The Home Assistant integration is local with no cloud account needed, and that is the big reason to choose it over cloud-only monitors. This listing is the current 120A V2 version, and Amazon's other Pro 3EM listings use different current ratings (63A clamps), so match the clamp rating to your supply.
What can Home Assistant control on the Shelly Pro 3EM?
| Control | Type | What it does |
|---|---|---|
| Power / energy per phase | Sensor | Live power and cumulative energy readings for each of the three phases. |
| Voltage / current | Sensor | Per-phase voltage and current, useful for spotting imbalance. |
Uses the core Shelly integration over your LAN (local push, no cloud). HA's docs do not name the Pro 3EM specifically; they state that all four Shelly generations are supported and that Gen2+ devices need firmware 1.0 or later, so a Pro 3EM falls under general Gen2+ support. Readings depend on correct time sync because Shelly relies on SNTP for power measurement. Mount and wire it per phase, then add it to HA's Energy dashboard using the per-phase energy sensors.
Specs
| rating | 120A per phase on this V2 listing |
|---|---|
| local api | Embedded web server, Shelly RPC/developer API, MQTT and scripting per retailer listings |
| form factor | DIN-rail, 3-phase energy meter with 3 clamp CTs |
| connectivity | Wi-Fi, Bluetooth and wired Ethernet (LAN) |
How does the Shelly Pro 3EM compare?
| Product | From | Protocol | Local control | Integration |
|---|---|---|---|---|
| Shelly Pro 3EM (this product) | £96.35 | Wi-Fi, Ethernet, Bluetooth | Yes | Native |
| Aqara Power Plug H2 UK (RGB) | £32.99 | Zigbee, Thread, Matter, Bluetooth | Yes | Works with HA |
| Aqara Wall Outlet H2 UK | £67.99 | Matter, Thread, Zigbee | Yes | Native |
| Eve Energy (Matter) UK Smart Plug | £39.95 | Thread, Matter, Bluetooth | Yes | Works with HA |
Frequently asked questions
- Does the Shelly Pro 3EM work with Home Assistant locally?
- Yes. The Shelly Pro 3EM is controlled locally in Home Assistant through a built-in Home Assistant core integration (shelly), so it keeps working if your internet connection or the Shelly cloud goes down. Control and state updates stay on your own network.
- Which protocol does the Shelly Pro 3EM use, and do I need a hub?
- The Shelly Pro 3EM uses Wi-Fi and Bluetooth. To pair it with Home Assistant you need no hub — it joins your Wi-Fi network directly; or a Bluetooth adapter on your Home Assistant host or an ESPHome Bluetooth proxy. Shelly's own hub is not required when you integrate through a built-in Home Assistant core integration (shelly).
- How much does the Shelly Pro 3EM cost in the UK?
- The lowest price we have listed for the Shelly Pro 3EM is £96.35 at Amazon UK. Prices were last checked in October 2026 and change often, so confirm on the retailer's page before buying.
Shelly
Shelly Pro 3EM
£96.35 at Amazon UK