Open box Shelly Pro 3EM (3xClamp 400A), three-phase WiFi energy meter, DIN rail mounting
Description
What does "open box" mean?
Open-box products are returned products with opened or damaged packaging, but fully checked from a technical point of view and completely functional. They come with the same warranty as new products.
Shelly Pro 3EM 400A is the high-load version of the Pro 3EM three-phase energy meter, supplied with current clamps rated for up to 400A per phase. It is the right choice for main electrical panels, commercial buildings, workshops or light industrial installations, where the currents involved far exceed those of an ordinary home and precise measurement is needed for efficient energy management.
Like the 120A version, the device measures voltage, current, active and apparent power, power factor and energy on each phase in real time, with support for 4-quadrant measurement, ideal for installations with their own energy generation (photovoltaic) on a larger scale. Data is stored locally for up to 60 days and can be accessed via Modbus, MQTT, HTTP or WebSocket, all secured with TLS.
Mounted on a DIN rail in the main electrical panel, the Pro 3EM 400A gives integrators and building managers a precise tool for internal billing, detecting abnormal consumption or optimising energy contracts, where precision and high current capacity matter most.
Practical use cases
- Mounted on the main electrical panel, it gives a real-time picture of the total consumption of the home, helping to identify the appliances that use the most energy.
- Used to monitor a dedicated circuit (air conditioning, heat pump, electric car charger), it lets you track the monthly costs of each individual load.
- Useful in systems with their own energy production (photovoltaic panels), to compare the energy produced with the energy consumed and optimise the use of large appliances during peak production hours.
- Sends alerts in the app in case of abnormal consumption, helping to quickly detect faulty equipment.
Technical specifications
| Mounting type | DIN rail, electrical panel |
| Phases measured | 3, plus neutral |
| Clamp included | 3 x 400A CT clamp |
| Accuracy | Class B, error below 1% |
| Metering | 4 quadrants, photovoltaic compatible |
| Local history | Up to 60 days, 1-minute interval |
| Connectivity | LAN, Wi-Fi, Bluetooth |
| Protocols | Modbus, MQTT, HTTP, WebSocket, TLS |
| Warranty | 5 years |
Shelly Pro 3EM 400A brings professional metering precision to high-consumption installations, where accurate energy monitoring is essential for costs and efficiency.