Shelly Pro EM-50 -- 2-Channel DIN Rail Energy Meter with Contactor Control (WiFi + LAN + Bluetooth)

Know exactly what every circuit is costing you. The Shelly Pro EM-50 is a DIN rail mountable, 2-channel, single-phase energy meter with 2 x 50A current transformers included. Monitor two circuits independently -- voltage, current, active power, apparent power, power factor, and accumulated kWh -- all in real time. A built-in dry contact relay lets you control a contactor directly from the meter, making it ideal for geyser scheduling, load control, and solar PV monitoring. 60 days of on-device data storage at 1-minute resolution ensures no data loss during network outages. Triple connectivity: WiFi, Ethernet (LAN), and Bluetooth. Supports MQTT, Modbus TCP, HTTP, WebSocket. No hub or subscription required. Made in Bulgaria.

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2 x 50A CTs

Included in Box

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1% Accuracy

Class B (IEC 62053-21)

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60-Day Storage

1-Min Resolution

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Solar PV Ready

4-Quadrant Metering

Key Features

2-Channel Energy Metering -- monitor two independent circuits on the same phase simultaneously; each channel reports voltage, current, active power, apparent power, power factor, and accumulated kWh
2 x 50A Current Transformers Included -- non-invasive CT clamps install around existing cables without cutting or rewiring; 50A per channel
1% Measurement Accuracy -- Class B accuracy (IEC 62053-21) for reliable billing-grade metering; voltmeter accuracy also 1%
Integrated Contactor Control -- built-in dry contact relay (2A at 240V AC) for switching a contactor; control geysers, HVAC, or high-load circuits directly from the meter
60-Day On-Device Data Storage -- stores metering data at 1-minute resolution in non-volatile memory; data survives network outages and power cycles; export as CSV or JSON
4-Quadrant Measurement -- measures both consumption and generation; ideal for solar PV systems to track grid import vs solar export
Triple Connectivity -- WiFi 802.11 b/g/n, Ethernet RJ45, and Bluetooth 4.2; Ethernet ensures reliable data in noisy panel environments
Modbus TCP -- native Modbus TCP support for integration with building management systems, SCADA, and industrial monitoring platforms
MQTT, HTTP, WebSocket -- full API access for Home Assistant, Node-RED, Grafana, and custom dashboards
Optical Pulse Indicator -- LED pulse indicates energy usage visually at the device
Built-in Temperature Sensor -- monitors ambient temperature inside the panel
Scripting (mJS) -- custom on-device automations for load balancing, threshold alerts, or contactor scheduling
No Hub or Subscription Required -- fully standalone; free cloud data via Shelly app or 100% local via Home Assistant

Perfect For

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Solar PV Monitoring

4-quadrant metering tracks grid consumption and solar production on two channels. See exactly how much you are exporting vs importing. Combine with contactor to dump excess solar to geyser.

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Geyser Energy Management

Monitor geyser kWh on one channel and use the built-in contactor output to schedule on/off times. Track daily heating costs. Set overpower alerts for element failure detection.

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Commercial Sub-Metering

Monitor two tenant circuits independently. 60 days of 1-minute data with CSV export for billing. Modbus TCP for BMS integration. Class B accuracy.

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Load Shedding Tracking

Monitor grid feed and inverter output. Track exactly when Eskom drops and how much battery or solar covers. Historical data survives outages thanks to on-device storage.

Home Assistant tip: The Pro EM-50 is auto-discovered by the Shelly integration. Each channel creates separate energy entities that feed directly into the Home Assistant Energy Dashboard. Add it as a grid consumption source or solar production source for automatic daily and monthly cost tracking.

Single-phase only. The Pro EM-50 monitors two circuits on the same single phase. For 3-phase installations, use the Shelly Pro 3EM instead. Both CT channels must share the same phase voltage reference.

Technical Specifications

Product	Shelly Pro EM-50
Model	SPEM-002CEBEU50
Type	2-Channel Single-Phase DIN Rail Energy Meter
Channels	2 (independent, same phase)
CT Clamps Included	2 x 50A current transformers
Max Current per Channel	50A RMS (via CT)
Measurement Accuracy	1% (ammeter 5-50A), 2% (ammeter 0-5A), 1% (voltmeter)
Accuracy Class	Class B (IEC 62053-21)
Metering	Voltage, current, active power, apparent power, power factor, accumulated energy (kWh), 4-quadrant
Contactor Output	1 x dry contact relay, 2A at 240V AC
Data Storage	60 days at 1-minute resolution (non-volatile)
Data Export	CSV (PQ logs), JSON (RPC API)
Power Supply	110-260V AC, 50/60 Hz
Power Consumption	Less than 3W
WiFi	802.11 b/g/n (2.4 GHz)
Ethernet	RJ45 (LAN)
Bluetooth	4.2
Protocols	MQTT, Modbus TCP, HTTP, WebSocket, Webhooks, TLS
CPU / Flash	ESP32-D0WDQ6 / 16 MB
Scripting	mJS (on-device)
Mounting	DIN rail
Dimensions (H x W x D)	94 x 19 x 69 mm
Weight	63 g
Colour	White
Operating Temperature	-20 to 40 degrees C
Humidity	30-70% RH
Certifications	CE, FCC, RoHS
Works With	Home Assistant, Alexa, Google Home, Samsung SmartThings
Hub Required	No
Made In	Bulgaria

What is in the Box

1 x Shelly Pro EM-50
2 x 50A Current Transformers (CT Clamps)
1 x Installation Guide

Frequently Asked Questions

Are the CT clamps included?

Yes. Two 50A current transformers are included in the box. They clip around existing cables -- no cutting or rewiring required.

Can it control a geyser contactor?

Yes. The built-in dry contact relay (2A at 240V AC) can switch a contactor coil directly. Wire the contactor through the relay output and schedule on/off times via the Shelly app or Home Assistant.

Does it work with solar PV systems?

Yes. 4-quadrant measurement means it tracks both consumption (import from grid) and generation (export from solar). Use one channel for grid and one for solar, or monitor two separate circuits.

Can it handle 3-phase?

No. The Pro EM-50 is single-phase only (two channels on the same phase). For 3-phase monitoring, use the Shelly Pro 3EM.

How long does it store data?

60 days at 1-minute resolution, stored in non-volatile memory on the device. Data survives power outages and network disconnections. Export as CSV or JSON via the API.

Does it work with Home Assistant?

Yes. Auto-discovered via the Shelly integration. Each channel creates separate energy entities that feed directly into the HA Energy Dashboard for cost tracking.