Shelly
Pro EM 50 Energy Meter
A two-channel DIN-rail meter for single-phase boards, reading up to 50 A on each channel through a clamp. It also has a dry contact relay for driving a contactor, which the Pro 3EM-3CT63 doesn't.
$139.95 inc GST In stock at supplier · dispatches in 2 business days
1
Free shipping over $150 Ordered in from our supplier. Allow about 2 business days before it dispatches.
30-day returns Unopened items in their original packaging
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 Pro EM-50 watches two single-phase circuits independently, reading up to 50 A on each through a current transformer clamp, and reports voltage, current, active and apparent power for both in real time. Two circuits from one rail position is the point: solar in on one channel and household draw on the other, or two tenancies off the same board. Unlike the Pro 3EM-3CT63, it has a built-in relay. It's a galvanically isolated dry contact for driving a contactor, not for carrying a load itself.
Two independent single-phase channels
Up to 50 A per channel through a CT clamp
±1% accuracy from 5 to 50 A
Built-in dry contact relay for contactor control
Sixty days of history, on the rail
This is a DIN-rail meter, so it lives in the switchboard alongside the breakers rather than in a wall box. It connects over ethernet or Wi-Fi, and it keeps at least sixty days of readings at one-minute resolution in non-volatile memory, with a real-time clock so the timestamps survive a network outage. Data comes out over MQTT, HTTP or WebSocket, with TLS on inbound connections.
DIN-rail mount, in the switchboard
60 days at one-minute resolution, stored on the device
Ethernet or Wi-Fi, with a real-time clock
MQTT, HTTP and WebSocket, TLS on inbound
How Shelly works
A Shelly is a small module that makes wiring you already have controllable. It joins your Wi-Fi directly, holds its schedules and scenes on the device itself, and keeps running them if your internet drops. Nothing you set up depends on Shelly's servers being reachable.
The device
The brain is the device
Shelly does the thinking locally, not in a data centre. Schedules, scenes and logic are stored on the unit and run there, so the lights still come on at dusk when the internet is out.
The network
No hub, no bridge
There is nothing to buy before the first one works. Where a Philips Hue setup is built around a Bridge that every light talks through, a Shelly joins your router directly and answers your phone from there.
The control
The app is optional
Every Shelly serves its own web interface, so you can set it up and run it from a browser on your own network, with no account. The Shelly Smart Control app and Shelly Cloud are free and add remote access and voice control, but nothing needs them.
The generations
What Gen1 to Gen4 means
Shelly has run through four hardware generations, and the same product name can exist in more than one of them. Later generations are faster and carry more radios than the ones before, which is why the generation is part of the name. The specifications on each page tell you which one you are looking at.
Getting started
1
It goes behind what you already have Start here
Shelly retrofits. The module fits behind the switch, socket or appliance that is already there, so your switch plates and fittings stay as they are and the original switch keeps working for anyone who just wants to flick it. Anything wired into a mains circuit is a job for a licensed electrician.
2
Open by design Then run it your way
Shelly publishes its local API and does not put it behind a developer account. Devices answer HTTP and MQTT on your own network and can run small scripts on themselves. That is why Shelly is the default choice for people building on Home Assistant, which ships an official Shelly integration.
Start with one and add more whenever you like. There is no hub to outgrow, and each Shelly works on its own whether you ever add another or not.
Works with
Also works with
-
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 your Wi-Fi
Joins your home network; control from the app, no hub or bridge needed.
-
Ethernet
-
Wi-Fi
Set up over Bluetooth
Used once, to get it onto your Wi-Fi.
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Bluetooth
Works offline
Runs on your home network. Only remote access needs the internet.
Specifications & Installation
Setup · 2:18
How to install it
Shelly's own step-by-step install, from isolating the power to mounting it on the DIN rail and wiring it in.
Watch setup videoNo specifications match.
Power
- Power
- Hardwired
- Standby power
- 3 W
- Phases
- Single-phase
- Channels
- 2 channels
- Measured by
- CT clamp
- Max current per circuit
- 50 A
- Accuracy (±)
- 1 %
- On-device history
- 60 days
- Relay output
- Yes
- Power supply voltage AC
- 100 - 260 V, 50/60 Hz
- Power supply voltage DC
- N/A
- 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
- Size (HxWxD)
- 94x19x69 ±0.5 mm / 3.70x0.75x2.71 ±0.02 in
- Weight
- 63 ±1 g / 2.22 ±0.05 oz
- Mounting
- DIN rail
- Screw terminals max torque
- 0.4 Nm / 4.43 lbin
- Conductor cross section
- 0.5 to 2.5 mm² / 20 to 14 AWG (solid, stranded and bootlace lugs)
- Conductor stripped length
- 6 to 7 mm / 0.24 to 0.28 in
- Color
- White
- Max switching voltage AC
- 240 V
- Max switching voltage DC
- N/A
- Max switching current
- 2 A
- Internal-temperature sensor
- Yes
- Voltmeter (RMS)
- 100 - 260 V
- Voltmeters accuracy
- ±1 %
- Ammeters (RMS via CT)
- 0 - 50 A
- Ammeters accuracy
- ±1 % (5 - 50 A), ±2 % (0 - 5 A)
- Power and energy meters
- * Active and apparent power * Active and apparent energy * Power factor
- Measurement data storage
- At least 60 days of 1 min data resolution
- Data export
- * CSV for PQ recorded values * JSON format export through RPC
- RF band
- 2400 - 2495 MHz
- Max. RF power
- <20 dBm
- CPU
- ESP32-D0WDQ6
- Flash
- 16 MB
- Webhooks (URL actions)
- 20 with 5 URLs per hook
- Scripting
- Yes
- MQTT
- Yes
- CoAP
- No
Common questions
Quick answers before you buy. We test this gear ourselves. Can't find yours? Ask our Melbourne team
Two independent single-phase circuits from one position on the rail. A common setup is solar generation on one channel and household draw on the other, so you can see import and export separately.
Not directly. Its relay is a galvanically isolated dry contact meant to drive a contactor, and the contactor does the switching.
This one is two single-phase channels to 50 A, with a relay built in. The 3CT63 is three phases to 63 A and has no relay at all. Pick on whether you're metering phases or separate circuits, and whether you need switching.
At least 60 days at one-minute resolution, stored on the device, with a real-time clock so the timestamps survive an outage.
Yes. It mounts in a switchboard and the clamps fit around live conductors. In Australia that must be done by a licensed electrician.
Shelly · Pro EM 50 Energy Meter