Frequently asked questions

• How many phases and clamps does the Shelly Pro 3EM 120A have?

  It is a three-phase meter and includes three split-core 120 A CT current transformers, one per phase, so it measures all three lines simultaneously.
• What is the measurement accuracy?

  The meter meets accuracy class B for active energy under IEC 62053-21, with a declared error of about ±1%, and supports four-quadrant measurement.
• How does it connect to the network?

  It offers three options: Wi-Fi 802.11 b/g/n, Bluetooth 4.2 for initial setup, and wired Ethernet via an RJ45 socket, handy in metal panels with weak Wi-Fi.
• Can I track each phase consumption separately?

  Yes, each CT clamp covers its own phase, and the meter shows voltage, current, power and energy separately for each of the three phases in the Shelly app.
• How long does the device keep data?

  It stores up to 60 days of data at one-minute resolution directly in memory, and this can be exported in CSV or JSON format for analysis.
• Why must I observe clamp direction during installation?

  Each CT clamp has an arrow showing current direction; if mounted reversed or matched to the wrong phase, power will read negative or distorted. Connection is done by an electrician.