Shelly Pro 3EM-400 DIN Rail 3-Phase Smart Energy Meter with Wi-Fi & LAN
The Shelly Pro 3EM-400 is a professional DIN rail mountable three-phase energy meter designed for advanced energy monitoring in homes, offices, and industrial installations. With Wi-Fi, Bluetooth, and LAN connectivity, this Gen2 device delivers real-time monitoring of voltage, current, power factor, and accumulated energy across three phases or individual circuits. Perfect for monitoring solar PV systems, business electrical circuits, appliances, and EV charging stations, the Shelly Pro 3EM-400 handles up to 400A per phase and features 1% active energy measurement accuracy (Class B compliance with IEC 62053-21). It stores up to 60 days of historical data with 1-minute resolution and requires no hub or subscription.
Advanced Energy Monitoring for Professionals
The Shelly Pro 3EM-400 provides real-time reporting of instantaneous voltage, current, active power, apparent power, and power factor per phase. It features 4-quadrant measurement, allowing it to track both energy consumption and production, making it ideal for photovoltaic (solar) installations and bi-directional energy flow monitoring. With support for MODBUS TCP, the device delivers precise data sampling with updates as fast as every 100 milliseconds using customizable firmware.
Key Features
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Measures up to 400A per phase: Includes 3 × 400A split-core current transformers (suitable for cables up to 35mm diameter)
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1% measurement accuracy: Class B active energy compliance based on IEC 62053-21 manufacturer testing
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Bi-directional energy monitoring: Tracks both consumption and production across three phases
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60-day data storage: On-device non-volatile memory with 1-minute interval logging
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Triple connectivity: Wi-Fi 802.11 b/g/n, Bluetooth, and Ethernet (RJ-45 LAN)
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Industry-grade security: mTLS support for MQTT, HTTP, and secure outbound WebSockets
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Phase sequence error detection: Optional monitoring to ensure correct wiring
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Optical pulse indication: Visual feedback for energy usage
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Scripting support: Gen2 firmware with mJS scripting for custom automation
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No hub required: Works standalone or integrates with Home Assistant, Amazon Alexa, Google Home, MQTT, and HTTP REST API
Professional Integration & Security
Built for professional integrators, the Shelly Pro 3EM-400 supports industry-grade mTLS encryption for secure cloud connectivity without the need for complex VPNs. It can operate standalone in a local LAN or Wi-Fi network, or be integrated into cloud-based home automation systems via MQTT, HTTP, and WebSocket protocols. All inbound connections support TLS encryption. The device is fully compatible with Home Assistant (local control), Amazon Alexa, Google Home, and supports advanced scripting for complex automation scenarios.
Solar & Renewable Energy Ready
The Shelly Pro 3EM-400 is photovoltaic ready, making it perfect for monitoring solar panel systems, wind turbines, and other renewable energy sources. Track real-time energy production, analyze two months of historical performance data, and link with other Shelly devices to automate energy management based on solar output. Automate heating, cooling, and EV charging with intelligent power shedding for optimized energy use.
Easy Installation & Flexible Configuration
The device mounts easily on standard DIN rails and features screw terminals for quick wiring (supports 0.5 to 2.5 mm² / 20 to 14 AWG conductors). It can be configured to measure a three-phase electrical system or three separate mono-phase circuits. The package includes 3 × 400A current transformers with snap-on, screwless mounting and 2-pin MX3.0-2x1Y connectors. An optional 4th CT can be used for neutral line monitoring (requires separate Shelly Pro Addon for contactor control).
Smart Monitoring & Alerts
Monitor your home, office, or factory in real-time and avoid unexpected expenses or voltage drops that can damage appliances and equipment. The free Shelly app (iOS and Android) allows you to manage spaces, monitor energy usage, track expenses, and set up automation rules. Upgrade to Shelly Cloud Premium for advanced features and extended data analytics.
What's in the Box
- Shelly Pro 3EM-400 Energy Meter (DIN rail mountable)
- 3 × 400A Current Transformers (CT) with 2-pin connectors
- Multilingual User and Safety Guide
Full Specifications
Electrical & Measurement
| Measurement Type |
3-phase energy meter (or 3 × mono-phase circuits) |
| Current Measurement Range |
Up to 400A per phase (plus neutral) |
| Current Transformers Included |
3 × 400A split-core CT (model CT315) |
| CT Cable Compatibility |
Up to 35mm diameter |
| Measurement Accuracy |
1% active energy (Class B, IEC 62053-21 compliant) |
| Measurement Type |
4-quadrant (capacitive and inductive loads, bi-directional) |
| Monitored Parameters |
Voltage, current, active power, apparent power, reactive power, power factor, accumulated energy |
| Data Update Rate |
As fast as 100ms (customizable via firmware) |
| Data Storage |
60 days, 1-minute intervals, non-volatile memory |
| Minimum Load per Channel |
500W |
Connectivity & Protocols
| Wi-Fi Protocol |
802.11 b/g/n |
| Wi-Fi Range |
Up to 30m / 100ft indoors, 50m / 160ft outdoors |
| Bluetooth |
Yes |
| Ethernet (LAN) |
RJ-45 connector |
| Simultaneous Connectivity |
Ethernet and Wi-Fi simultaneously supported |
| Supported Protocols |
MQTT, HTTP, WebSocket (inbound/outbound), UDP, MODBUS TCP |
| Security |
mTLS for MQTT, HTTP, and secure outbound WebSockets; TLS for inbound connections |
| Cloud Integration |
Shelly Cloud (optional, no subscription required) |
| Smart Home Compatibility |
Home Assistant (local), Amazon Alexa, Google Home |
| Scripting |
mJS scripting support (Gen2 firmware) |
Physical & Installation
| Dimensions (L × W × H) |
94 × 19 × 69 mm (±0.5mm) |
| Weight |
62g (±1g) |
| Mounting |
DIN rail (standard) |
| Housing Material |
Plastic |
| Terminal Type |
Screw terminals |
| Max Screw Torque |
0.4 Nm |
| Conductor Cross-Section |
0.5 to 2.5 mm² / 20 to 14 AWG (solid, stranded, ferrules) |
| Wire Stripping Length |
6 to 7mm |
| Operating Altitude |
Up to 2000m / 6562ft |
Features & Options
| Phase Sequence Error Detection |
Yes (optional, based on zero-crossing detection) |
| Optical Pulse Indicator |
Yes (red LED flashes based on energy flow) |
| Real-Time Clock |
Yes (maintains time if SNTP server connection lost) |
| Built-in Relay |
No (requires Shelly Pro Addon for contactor control) |
| Photovoltaic (PV) Ready |
Yes |
| Firmware Generation |
Gen2 (Plus/Pro series) |
Warranty & Compliance
| Manufacturer Warranty |
5 years (Shelly Pro series) |
| Protection Plus Available |
Yes (12-month replacement for any damage including improper wiring) |
| Compliance |
IEC 62053-21 (Class B), EU Declaration of Conformity, UK PSTI ACT |
| Manufacturer Certifications |
ISO 14001:2015, ISO 27001:2022, ISO 9001:2015 |
| Design & Development |
EU (Shelly Europe) |
Specifications are sourced from the manufacturer product page and may be updated.
