SHELLY 120A Current Transformer Energy Meter CT

Monitoring high-current circuits often means bulky meters, complex wiring, or sacrificing accuracy. The SHELLY 120A Current Transformer Energy Meter CT solves this by providing precise, real-time energy tracking for two independent channels, using split-core CT clamps that install without interrupting power. Ideal for sub-metering, solar monitoring, or industrial equipment, it brings professional-grade measurement to any Wi-Fi-enabled space.

Who is it for

Electricians, facility managers, and smart home enthusiasts who need to monitor heavy loads—heat pumps, EV chargers, workshop machinery—or want granular energy data per circuit. If you need to track consumption, detect overconsumption, or integrate with automation platforms, this device delivers.

Main features

• Dual-channel measurement: Monitor two separate circuits simultaneously, each up to 120A, with included split-core CT clamps.
• High accuracy: Class B (EN 50470-3) / Class 1 (IEC 62053-21) metering ensures reliable data for billing or optimization.
• Comprehensive parameters: Real-time power, total energy, voltage, current, power factor, and frequency—all accessible locally or via cloud.
• Built-in energy history: Stores up to 365 days of data on-device, so you never lose insights during network outages.
• Overconsumption protection: Set thresholds and receive alerts or trigger actions when current exceeds safe limits.
• Potential-free relay output: One dry contact (max 2A, 230V AC) for controlling external devices based on measured values.
• Flexible integration: Works with MQTT, REST API, Shelly Cloud, and Home Assistant for seamless automation.
• Wide voltage range: Operates from 110V to 230V AC, covering most residential and light commercial systems.

Specifications

• Power supply: AC 110-230V, 50/60Hz
• Max current per channel: 120A (with included CT clamps)
• CT clamps included: 2x 120A split core current transformers
• Relay output: 1x potential-free contact (max 2A, 230V AC)
• Wireless protocol: Wi-Fi 802.11 b/g/n (2.4GHz)
• Operating temperature: -40°C to 40°C
• Power consumption: < 1W
• Energy history: Up to 365 days built-in
• Measurement parameters: Real-time power, total energy, voltage, current, power factor, frequency
• Metering accuracy: Class B (EN 50470-3) / Class 1 (IEC 62053-21)
• Integration: MQTT, REST API, Shelly Cloud, Home Assistant
• Overconsumption protection: Yes
• Voltage measurement range: 110-230V AC
• Current measurement range: 0-120A per channel
• Mounting: Wall mount / DIN rail compatible (with optional accessory)
• Dimensions (main unit): 39 x 23 x 14 mm
• Weight (main unit): 62g
• Certifications: CE, RoHS
• Firmware updates: Over-the-air (OTA)

Tips

For best accuracy, ensure the CT clamps are fully closed around the conductor and not installed near strong magnetic fields. Use the built-in relay to disconnect a load when overconsumption is detected, or to trigger an alarm. Pair with a Shelly smart plug for complete energy management of smaller devices on the same network.