EM Gen3 Energy Meter
A clamp-based energy meter small enough to sit in a wall box. Two clamps, so it can watch two circuits at once, with a 50 A clamp in the box and a dry contact relay for driving a contactor.
Currently sold out.
Everything you need to know
The sections below cover what this meter does, the jobs people put it on, the full specifications, and how warranty and returns work. If something's still unanswered, the questions at the bottom cover the common ones.
Product features
What this meter does
The EM Gen3 measures with current transformers: a split clamp that closes around a live conductor, so the circuit never passes through the meter itself. That's what lets a small in-wall module read a heavy circuit. It takes up to two clamps, so one unit can watch two circuits, and a 50 A clamp comes in the box. It also has a dry contact relay rated 2 A at 240 V. That isn't for switching a load directly, it's for driving a contactor that does.
- Up to two CT clamps, two circuits from one meter
- 50 A clamp included, 80 A available separately
- Reads to 80 A, ±2% accuracy
- Dry contact relay for contactor control
Ten days of history on the device
The meter keeps at least ten days of readings at one-minute resolution in its own storage. You can pull that back later without a cloud account holding it for you, and a dropout doesn't leave a hole in the record.
- At least 10 days at one-minute resolution
- Stored on the device, not in a cloud account
- Readable over the local API
Automations that don't need the internet
Schedules, timers and scenes run on the relay itself, not on a server overseas. Set lights for sunset, a towel rail for weekday mornings, or a fan to run down after the bathroom light goes off, and it all keeps working through an internet outage. There's no subscription, and the embedded web interface gives you full control from a browser on your own network.
- Schedules and scripts run on the device
- No cloud account required for local control
- Keeps working when the internet doesn't
What is a Shelly energy meter?
A Shelly energy meter measures the power a circuit is using. It shows how much that circuit is using right now, keeps a running total of how much it has used over time, and stores one-minute records on the meter itself. It does not turn anything on or off, so every switch and appliance on the circuit works exactly as it did before the meter went in. You see the numbers in the Shelly app, or in Home Assistant through its Shelly integration, with no Shelly account in the middle.
See where the power goes
Clamp the mains where they land in the switchboard and you see what the whole house is using, right now and over time. Put a meter on a single circuit, like the hot water or the air conditioner, and you see what that one thing costs to run.
Switch a load off when it runs high
An automation can run when a circuit climbs past a figure you set, like turning a heater off during a high tariff window. The meter supplies the reading, and a relay or a contactor does the switching. The EM Gen3 and Pro EM-50 have a built-in output for driving a contactor.
Import and generation, separately
One channel on the mains and one on the solar circuit gives you what you imported and what your roof made, as two separate numbers. A single channel nets them together and hides both. The clamp reads the current in the cable, so the meter works the same whoever made the panels or the inverter.
Know when something finishes or fails
When a circuit drops to nothing, whatever was running has finished, so an automation can tell you the washing machine is done. An old fridge or a pool pump drawing more than it used to is often the first sign it needs a service.
Start with what you want to know Start here
One appliance, or the whole house? A single circuit you can reach in the wall is an EM Mini Gen4 job. The EM Gen3 clamps up to two circuits, or the mains of a single phase house. For something more substantial that lives in your switchboard, look at the Pro range, which clips onto the DIN rail.
Add more as you go Then
Each meter works independently, so you can start with a single circuit and add more as you need them. They don't need to match: mix models and generations, and they sit side by side in the Shelly app or Home Assistant.
What's in the box
- 1× Shelly EM Gen3 energy meter
- Single phase, two metering channels
- 1× 50 A current transformer clamp
- Covers one channel. A second clamp is needed to meter the second channel
Works with
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Pairs with Amazon Alexa
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Pairs with Google Home
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Pairs with Home Assistant
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Pairs with SmartThings
Joins your home network, so you control it from the app with no hub or bridge.
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Wi-Fi
Used once, to get it onto your Wi-Fi.
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Bluetooth
Works offline
Keeps working on your home network when the internet is down.
Scripts
15
Give it jobs the app can't
Scripts add jobs the meter can't do with the Shelly app's schedules and actions alone, like acting on the weather forecast or sending an alert to your phone. Each one is a small program that runs on the meter itself: copy it, paste it into the device's script editor and press Start. It doesn't need a hub, a cloud account or a subscription.
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Energy Load shedding: switch an appliance off when the draw gets too high -
Energy Phone alert when today's power use passes your daily limit -
Energy Track your peak demand on a demand tariff, with a daily report -
Energy What your home's standby power costs, reported every morning -
Energy What your power costs on a time-of-use tariff, worked out daily -
Notifications Phone alert when your mains voltage goes too high or too low
Specifications & Installation
Setup · 2:21
How to install it
Shelly's own step-by-step install, from isolating the power to fitting the clamp and wiring the meter in.
Watch setup videoNo specifications match.
- Power
- Hardwired
- Standby power
- < 1.2 W
- Phases
- Single-phase
- Channels
- 2 channels
- Measured by
- CT clamp
- Max current per circuit
- 80 A Also available: Mini
- CT clamps included
- Yes
- Accuracy (±)
- 2 %
- On-device history
- 10 days
- Relay output
- Yes
- Relay rating
- 2 A
- Power supply
- 110 - 240 V~ 50/60 Hz
- External protection
- 2 A, tripping characteristic B or C, 6 kA interrupting rating, Energy limiting class 3
- Form
- In-wall
- Housing material
- Plastic
- Standard
- 802.11 b/g/n
- Range (indoors)
- 30 metres
- RF band
- 2412 - 2472 МHz
- Max. RF power
- < 20 dBm
- Version
- 4.2
- Range (indoors)
- 10 metres
- RF band
- 2402 - 2480 MHz
- Max. RF power
- < 4 dBm
- Operating temperature
- -20–40 °C
- Operating humidity
- 30–70 % RH
- Max altitude
- 2000 metres
- Size (HxWxD)
- 37x42x16 mm / 1.46x1.65x0.63 inch
- Weight
- * EM Gen3 - 23 g / 0.81 oz * CT 50A - 50 g / 1.76 oz
- Screw terminals max torque
- 0.4 Nm / 3.5 lbin
- Conductor cross section
- 0.5 to 4 mm² / 20 to 11 AWG (solid, stranded, and bootlace ferrules)
- Conductor stripped length
- 6 to 7 mm / 0.24 to 0.28 in
- Mounting
- Wall console, Electrical cabinet
- Shell color
- * White * Charcoal gray
- Connectors color
- Black
- Max. switching voltage
- 240 V~
- Max. switching current
- 2 A/240 V~
- Voltmeter (AC)
- 110-240 V~ 50/60 Hz
- Voltmeter accuracy
- ±2%
- Ammeter (AC)
- 0 - 80A
- Ammeter accuracy
- ±2 % (2 - 50 A), ±2 % (1 - 2 A), ±5 % (0 - 1 A)
- Compatible current transformers
- * CT 50A (included in the package) * CT 80A
- Power and energy meters
- * Active and apparent power * Active and apparent energy * Power factor * Fundamental active and fundamental reactive energy
- Channel-to-channel calibration minimum load
- 500 W
- No load threshold
- 30 VA per channel
- Measurement data storage
- At least 10 days of 1 min data resolution
- Data export
- * CSV for PQ recorded values * JSON format export through RPC
- Internal-temperature sensor
- Yes
- CPU
- ESP-Shelly-C38F
- Flash
- 8 MB
- Schedules
- Yes
- Webhooks (URL actions)
- 20 with 5 URLs per hook
- Scripting
- Yes
- MQTT
- Yes
- Encryption
- Yes (Transport level)
- Authentication
- Yes (Application and transport level)
- SKU
- SHE-SNS-0002
- MPN
- S3EM-002CXCEU
- Barcode
- 3800235261873
Common questions
Quick answers before you buy. We test this gear ourselves. Can't find yours? Ask our Melbourne team
It's a split ring that closes around a live conductor and reads the current passing through it without being wired into the circuit. A 50 A clamp comes in the box. An 80 A clamp is available separately if you need the full range.
Yes. It has two current transformer inputs, so one meter can read two circuits with a second clamp added.
Not on its own. The relay is a dry contact rated 2 A at 240 V, which is meant to drive a contactor rather than carry a load itself. Your electrician wires the contactor to do the switching.
Yes. It's mains powered at 110 to 240 V and needs both a live and a neutral at the install point.
Yes. Fitting the clamp means opening up a switchboard or a wall box, which is a job for a licensed electrician in Australia. It's usually a single visit.