Pro 3EM-400 Energy Meter
The 400 A version of Shelly's three-phase switchboard meter. Its clamps open to 35 mm, so they reach around mains tails a 120 A clamp cannot.
$419.95 inc GST In stock at supplier · dispatches in 5 business days
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Comes with free shipping Ordered in from our supplier. Allow about 5 business days before it dispatches.
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3-year warranty Backed by Shelly
Everything you need to know
The same three-phase DIN rail meter as the standard Pro 3EM, with a current range built for a heavy supply. It takes CT 400A clamps, reads to 400 A per phase and holds at least 60 days of one-minute data on the device. Like the rest of the line it measures without switching: contactor control is the Pro 3EM Switch Add-on.
Product features
Built for the incomer, not the circuit
The CT 400A opens to 35 mm against the 15 mm of the standard clamp, so it closes around mains tails rather than individual circuits. That is what puts this meter on a large home with a heavy supply, a farm shed or a small commercial board.
- Reads to 400 A per phase
- 35 mm clamp opening
- One clamp per phase, plus an optional fourth on the neutral
Accurate where the load is
It holds within 1% from 5 A right up to 400 A, and within 2% below that. On a supply this size the lower band is worth knowing: a 400 A meter is the right tool for watching a whole switchboard and the wrong one for chasing a small standby load.
- Within 1% from 5 A to 400 A
- Within 2% below 5 A
- Four-quadrant, so export is measured too
Your history stays on the device
It keeps at least 60 days of readings at one-minute intervals in its own memory, on the meter rather than on a server somewhere. The detail is still there after an internet outage, and you can pull it out as CSV or JSON without a cloud account.
- At least 60 days of one-minute readings, stored on the meter
- No cloud account needed to keep them
- Export as CSV or JSON
Wired into your network
An RJ45 port puts it on the network by cable, which is the dependable option inside a metal switchboard. Wi-Fi is the fallback, and it speaks MQTT, HTTP and WebSocket over TLS, so it fits into Home Assistant and anything else you run locally.
- Ethernet, with Wi-Fi as backup
- MQTT, HTTP and WebSocket, all over TLS
- Works locally, with or without the cloud
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.
Power usage
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.
Automations
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.
Solar
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.
Alerts
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.
Getting started
1
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.
2
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 Pro 3EM-400 energy meter
- Three phase, DIN rail mount
- 3× 400 A current transformer clamp
- One per phase. A neutral clamp is optional and not included
Works with
Also 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
Connects over
On Wi-Fi or Ethernet
Joins your home network, so you control it from the app with no hub or bridge.
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Ethernet
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Wi-Fi
Set up over Bluetooth
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
4
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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Garden Frost alert on your phone the evening before a cold night -
Notifications Phone alert when a Shelly goes offline -
Network Phone alert when your home's public IP address changes -
Notifications Phone message when the power comes back, with how long it was off
Scripts are free; installing one takes about two minutes.
Specifications
No specifications match.
Power
- Power
- Hardwired
- Standby power
- < 3 W
- Phases
- Single-phaseThree-phase
- Channels
- 3 channels
- Measured by
- CT clamp
- CT opening
- 35 mm
- CT clamps included
- Yes
- Accuracy (±)
- 1 %
- Solar export metering
- Yes
- On-device history
- 60 days
- Relay output
- No
- Form
- DIN-rail
- Housing material
- Plastic
- Standard
- 802.11 b/g/n
- Range (indoors)
- 30 metres
- Version
- 4.2
- Range (indoors)
- 10 metres
- Operating temperature
- -20–40 °C
- Operating humidity
- 30–70 % RH
- Max altitude
- 2000 metres
- SKU
- SHE-SNS-0012
Common questions
Quick answers before you buy. We test this gear ourselves. Can't find yours? Ask our Melbourne team
When the conductor is too thick for a 120 A clamp, or the circuit draws more than 120 A. The CT 400A opens to 35 mm against the CT 120A's 15 mm.
Within 1% from 5 A to 400 A, and within 2% below 5 A. On a supply this size, small standby loads sit in that lower band.
In the switchboard, on the DIN rail. It's licensed-electrician work in Australia.
Not on its own. There's no relay inside it. The Pro 3EM Switch Add-on gives it one output, and that output drives a contactor coil rather than carrying the load.
No. It runs on your own network, stores its own history and speaks MQTT, HTTP and WebSocket locally.
Shelly · Pro 3EM-400 Energy Meter