Shelly
Shelly EM Gen3 Energy Meter (50A CT clamp)
- Wi-Fi
- Bluetooth
Verified September 2026
The step beyond plug-level monitoring: a CT-clamp meter that sits in your consumer unit and feeds two circuits' worth of power into HA's Energy dashboard via the core Shelly integration — all local, no subscription. Compare that to the Hildebrand Glow: Glow reads your actual smart meter register for one whole-home import/export figure, while the EM Gen3 clamps onto specific cables you choose — grid tails, a solar inverter, an EV charger — so it's more flexible but per-circuit rather than automatically whole-home. Shelly quotes ±2% current accuracy rather than a formal IEC class. Needs an electrician unless you're confident around the consumer unit.
In Home Assistant
| Control | Type | What it does |
|---|---|---|
| Power (per channel) | Sensor (W) | Instantaneous active power; reads negative when that channel is net-exporting, e.g. the solar channel during daylight generation. |
| Energy consumed | Sensor (kWh) | Cumulative energy drawn from the grid on that channel; assign to the Energy dashboard's grid-consumption slot. |
| Energy returned | Sensor (kWh) | Cumulative energy exported/returned on that channel; assign to the Energy dashboard's return-to-grid or solar-production slot. |
| Reverse CT direction | Config (per channel) | Flips a channel's sign in software when its CT clamp was fitted backwards, avoiding a physical re-clamp in the consumer unit. |
| Voltage / current / power factor | Sensor | Diagnostic readings alongside power/energy; a near-zero reading on an active circuit typically indicates the CT is clamped on neutral rather than live. |
Each channel exposes a signed instantaneous power sensor plus two separate cumulative energy counters — consumed and returned — rather than one net figure, because HA's Energy dashboard config wants distinct grid-consumption and return-to-grid sensors, not a value that just goes negative on export; the solar-feeding channel's returned-energy entity plugs straight into that slot. Community reports on Shelly EM devices confirm a mis-oriented CT clamp flips a channel's sign entirely, and Shelly's own troubleshooting handles this with a per-channel reverse-direction toggle in the web UI rather than requiring a physical re-clamp. It's worth spot-checking after firmware or HA core updates that both consumed and returned entities remain present and incrementing independently, since sibling Gen3 metering devices have shipped bugs where the two got summed into one counter.
Specs
- channels
- 2
- ct clamp
- 50A included; optional CT80A clamp available for higher-current circuits (jaw/cable-diameter limits not published by Shelly)
- dimensions
- 37 x 42 x 16mm, 23g (device only, excludes CT clamps)
- hub required
- false
- installation
- Wall/electrical-cabinet mount inside or beside the consumer unit — not a clip-on DIN rail unit itself, but small enough to fit in a DIN enclosure alongside DIN-rail gear
- data retention
- At least 10 days of local 1-minute-resolution data on-device
- current accuracy
- ±2% (2-50A), ±2% (1-2A), ±5% (0-1A) per Shelly's published figures — no formal IEC accuracy class stated
- voltage accuracy
- ±2%
- energy monitoring
- true
- measurement range
- 0-80A per channel; 110-240V AC, 50/60Hz