The Smart Device Compare comparison
Shelly Pro 3EM-400 vs Shelly Pro EM-50
Understand the differences. Decide what matters to your home.
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Key differences between Shelly Pro 3EM-400 and Shelly Pro EM-50
A summary of selected recorded differences between these energy monitors. Check the full specification table below for details and conditions.
Feature differences among your selected devices
- Relay Output (features): Shelly Pro 3EM-400 — No (No built-in relay, contactor control needs the Shelly 3EM Switch Add-on); Shelly Pro EM-50 — Yes (Integrated switch with potential-free contacts, 2 A at 240 V).
- Three Phase (metering): Shelly Pro 3EM-400 — Yes; Shelly Pro EM-50 — No.
Specifications to check side by side
- Power Supply (installation): Shelly Pro 3EM-400 — Mains (110-240 V); Shelly Pro EM-50 — Mains (100-260 V).
- Included Ct Sensors (metering): Shelly Pro 3EM-400 — 3 (3 x 400 A current transformers); Shelly Pro EM-50 — 2 (2 x 50 A current transformers).
- Main Ct Rating (metering): Shelly Pro 3EM-400 — 400 A; Shelly Pro EM-50 — 50 A.
- Monitored Circuits (metering): Shelly Pro 3EM-400 — 3 (Three phases, or three single-phase circuits); Shelly Pro EM-50 — 2.
Information still to confirm
- 3 of 39 comparison fields lack a resolved value for at least one selected device. Missing information is not evidence that a feature is absent.
- Check the full table and manufacturer documentation before ruling out a device.
These observations are derived from recorded catalog data and have not all been independently verified. Confirm details with the manufacturer before purchasing.
Compare capabilities, compatibility and setup requirements.
What the catalog tells us
Understand the tradeoffs.
These counts describe the available data, not a quality score. More features do not automatically make a better device.
6differences with recorded values for every device
3rows with missing or unspecified information
Your priorities, side by side
Focus on what changes.
Mark the specifications you care about. Open manufacturer sources for verification scope; fields without citations remain catalog data. Expand notes for other qualifications.
Showing 39 of 39 rows. “Not recorded” does not mean “No”.
Connectivity
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
- Shelly Pro 3EM-400
- Yes
Catalog note
Also works as a Bluetooth gateway
- Shelly Pro EM-50
- Yes
Catalog note
Bluetooth 4.2, also works as a Bluetooth gateway
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Modbus
- Shelly Pro EM-50
- Modbus
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
Data Monitoring
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
Catalog note
CSV export of the consumption chart
- Shelly Pro 3EM-400
- 60 days
Catalog note
60 days of 1-minute data stored on the device
- Shelly Pro EM-50
- 60 days
Catalog note
At least 60 days of 1-minute data stored on the device
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Not recorded
- Shelly Pro EM-50
- Not recorded
- Shelly Pro 3EM-400
- Yes
Catalog note
Cost periods and tariff distribution in the Shelly Smart Control app
- Shelly Pro EM-50
- Yes
Catalog note
Cost periods and tariff distribution in the Shelly Smart Control app
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
Features
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Yes
Catalog note
Scripts and webhooks shed or enable loads from the readings
- Shelly Pro EM-50
- Yes
Catalog note
Configurable load control to divert surplus PV production
- Shelly Pro 3EM-400
- No
Catalog note
No built-in relay, contactor control needs the Shelly 3EM Switch Add-on
- Shelly Pro EM-50
- Yes
Catalog note
Integrated switch with potential-free contacts, 2 A at 240 V
Installation
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Yes
Catalog note
One DIN module, but the 400 A clamps are bulky
- Shelly Pro EM-50
- Yes
Catalog note
One DIN module wide
- Shelly Pro 3EM-400
- Mains (110-240 V)
- Shelly Pro EM-50
- Mains (100-260 V)
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
Integrations
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- No
- Shelly Pro EM-50
- No
- Shelly Pro 3EM-400
- Yes
Catalog note
Via the official Shelly Cloud integration
- Shelly Pro EM-50
- Yes
Catalog note
Via the official Shelly Cloud integration
Local Control
- Shelly Pro 3EM-400
- Yes
Catalog note
RPC over HTTP and WebSocket, plus Modbus, webhooks and scripting
- Shelly Pro EM-50
- Yes
Catalog note
RPC over HTTPS and WebSocket, UDP, webhooks, scripting and Modbus TCP
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
Metering
- Shelly Pro 3EM-400
- ±1%
Catalog note
Accuracy Class B for active energy
- Shelly Pro EM-50
- ±1%
Catalog note
Accuracy Class B for active energy, ±1% from 5 A to 50 A
- Shelly Pro 3EM-400
- Yes
Catalog note
4 quadrant measurement, produced and used energy per phase
- Shelly Pro EM-50
- Yes
Catalog note
4 quadrant measurement with a returned energy counter
- Shelly Pro 3EM-400
- Not applicable / unspecified
- Shelly Pro EM-50
- Not applicable / unspecified
- Shelly Pro 3EM-400
- 3
Catalog note
3 x 400 A current transformers
- Shelly Pro EM-50
- 2
Catalog note
2 x 50 A current transformers
- Shelly Pro 3EM-400
- 400 A
- Shelly Pro EM-50
- 50 A
- Shelly Pro 3EM-400
- 3
Catalog note
Three phases, or three single-phase circuits
- Shelly Pro EM-50
- 2
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- Yes
Catalog note
Active and apparent power, power factor, frequency and voltage
- Shelly Pro 3EM-400
- Not recorded
- Shelly Pro EM-50
- No
Catalog note
Single-phase device with two current channels
- Shelly Pro 3EM-400
- Yes
- Shelly Pro EM-50
- No
| Specification | Shelly Pro 3EM-400 | Shelly Pro EM-50 |
|---|---|---|
| Connectivity | ||
| Yes | Yes | |
| No | No | |
YesCatalog noteAlso works as a Bluetooth gateway | YesCatalog noteBluetooth 4.2, also works as a Bluetooth gateway | |
| Yes | Yes | |
| Modbus | Modbus | |
| No | No | |
| No | No | |
| No | No | |
| Data Monitoring | ||
| Yes | YesCatalog noteCSV export of the consumption chart | |
60 daysCatalog note60 days of 1-minute data stored on the device | 60 daysCatalog noteAt least 60 days of 1-minute data stored on the device | |
| Yes | Yes | |
| Not recorded | Not recorded | |
YesCatalog noteCost periods and tariff distribution in the Shelly Smart Control app | YesCatalog noteCost periods and tariff distribution in the Shelly Smart Control app | |
| Yes | Yes | |
| Features | ||
| Yes | Yes | |
YesCatalog noteScripts and webhooks shed or enable loads from the readings | YesCatalog noteConfigurable load control to divert surplus PV production | |
NoCatalog noteNo built-in relay, contactor control needs the Shelly 3EM Switch Add-on | YesCatalog noteIntegrated switch with potential-free contacts, 2 A at 240 V | |
| Installation | ||
| Yes | Yes | |
YesCatalog noteOne DIN module, but the 400 A clamps are bulky | YesCatalog noteOne DIN module wide | |
| Mains (110-240 V) | Mains (100-260 V) | |
| No | No | |
| Integrations | ||
| Yes | Yes | |
| No | No | |
| Yes | Yes | |
| Yes | Yes | |
| No | No | |
YesCatalog noteVia the official Shelly Cloud integration | YesCatalog noteVia the official Shelly Cloud integration | |
| Local Control | ||
YesCatalog noteRPC over HTTP and WebSocket, plus Modbus, webhooks and scripting | YesCatalog noteRPC over HTTPS and WebSocket, UDP, webhooks, scripting and Modbus TCP | |
| Yes | Yes | |
| Yes | Yes | |
| Metering | ||
±1%Catalog noteAccuracy Class B for active energy | ±1%Catalog noteAccuracy Class B for active energy, ±1% from 5 A to 50 A | |
YesCatalog note4 quadrant measurement, produced and used energy per phase | YesCatalog note4 quadrant measurement with a returned energy counter | |
| Not applicable / unspecified | Not applicable / unspecified | |
3Catalog note3 x 400 A current transformers | 2Catalog note2 x 50 A current transformers | |
| 400 A | 50 A | |
3Catalog noteThree phases, or three single-phase circuits | 2 | |
| Yes | YesCatalog noteActive and apparent power, power factor, frequency and voltage | |
| Not recorded | NoCatalog noteSingle-phase device with two current channels | |
| Yes | No | |
Know what’s behind the comparison.
The table matches specifications by section and field. It preserves notes, separates missing data from explicit “No” values, and keeps qualifications attached to their values. No overall winner is assigned from feature counts.
Read our comparison methodology