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Metering – Difference Between ID1 and ID2 Meters

Meters can be assigned an ID number between 1 and 8, defining their role within the system.

The ID1 meter is always the main grid meter, while ID2–ID8 are used for monitoring additional devices.

Meter Roles

ID – ID1

Function – Main grid import/export meter

Typical Use Case – Monitors total property energy flow

ID – ID2

Function – Secondary generation or device meter

Typical Use Case – Tracks external PV generation

ID – ID3–ID8

Function – Reserved for future integrations

Typical Use Case – Potential for EVs, heat pumps, etc.

Example Setup

  • ID1 (Grid): Measures total property load and grid import/export.
  • ID2 (PV String): Measures an external PV system’s generation before the inverter.
    The inverter uses both meters to optimise battery charge/discharge and overall energy balance.

Notes

  • Only ID1 communicates directly with the inverter.
  • ID2 meters are bridged to the same voltage reference as ID1 for accurate phase correlation.
  • ID2 CTs must clamp the PV inverter’s live feed, arrow pointing toward property load.