Victron Energy Meters: ET112, ET340, and EM24 Selection and Configuration

Victron Energy systems rely on accurate energy measurement for optimal performance, especially in Energy Storage System (ESS) configurations. This guide details the selection and basic ModbusTCP configuration of Victron's Carlo Gavazzi energy meters: the ET112, ET340, and EM24. These meters are crucial for monitoring grid interaction and facilitating features like zero feed-in limiting.

Understanding Victron Energy Meters

Victron Energy offers a line of dedicated energy meters for integration into their systems. These meters, manufactured by Carlo Gavazzi, are designed to provide precise AC energy measurements.

ET112 Single-Phase Energy Meter

The ET112 is a single-phase energy meter. It is typically used in systems where only one AC phase requires monitoring, such as residential installations with a single-phase grid connection. The ET112 is used for AC-Thor integration.

ET340 Three-Phase Energy Meter

For three-phase electrical systems, the ET340 is the appropriate energy meter. It measures energy across all three phases, providing comprehensive data for larger residential or commercial installations. The ET340 is used for AC-Thor integration.

EM24 Three-Phase Energy Meter

Similar to the ET340, the EM24 is also a three-phase energy meter. It serves the same function of measuring energy in three-phase systems and is also used for AC-Thor integration.

Selecting the Right Energy Meter

The primary criterion for selecting a Victron Energy Meter is the type of AC electrical system it will monitor:

• For single-phase systems: Choose a single-phase meter like the ET112. When configuring, you would select 'Victron 1ph Manual' in the relevant settings.
• For three-phase systems: Choose a three-phase meter like the EM24 or ET340. Configuration involves selecting 'Victron 3ph Manual'.

ModbusTCP Integration and Configuration

Victron Energy Meters communicate with GX devices (like the Cerbo GX) primarily via ModbusTCP. This allows the GX device to read energy data and control certain functions based on these readings.

ModbusTCP Communication Parameters

For systems integrating with AC-Thor, communication with the energy meter is standardized:

• Port: Communication is done through ModbusTCP Port 502.
• Device ID: The Device ID for the meter will be set to 0.
• ModbusTCP Registers:
• • For single-phase meters (e.g., ET112), the ModbusTCP registers will be set to 820.
  • For three-phase meters (e.g., EM24 or ET340), the ModbusTCP registers will be set to 820, 821, and 822.

Application: Zero Feed-in Limiting with AC-Thor

These energy meters play a role in advanced energy management, such as zero feed-in limiting. For instance, when integrated with an AC-Thor device, the system can control the energy sent to a boiler to limit grid feed-in to approximately 50W. This functionality relies on the accurate grid measurements provided by the energy meter.

Safety Considerations

Working with AC electrical systems carries inherent risks. Always ensure the following:

• Isolate Power: Before installing or working on any energy meter, ensure all AC power sources (grid, inverter, generator) are disconnected and locked out.
• Qualified Personnel: Installation and configuration should only be performed by qualified and authorized electrical technicians.
• Insulated Tools: Use appropriate insulated tools to prevent accidental short circuits or electrical shock.
• Local Regulations: Adhere to all local electrical codes and safety regulations.

Conclusion

Victron Energy Meters (ET112, ET340, EM24) are essential components for accurate energy monitoring and advanced system control in Victron ESS installations. Proper selection based on your AC system's phase configuration and correct ModbusTCP setup ensures seamless integration and reliable performance, enabling features like precise grid interaction and zero feed-in limiting.