FoxESS H3-Pro/Smart Series Hybrid Inverter (grid)
The FoxESS H3-Pro/Smart Series is a three-phase hybrid inverter designed for residential and light-commercial solar-plus-storage installations. This Modbus RTU template reads the built-in Meter1/CT1 grid interface, exposing per-phase active power on phases R, S, and T (registers 38816, 38818, and 38820) and cumulative grid-import energy (register 39617). Together these four registers give you a complete real-time and historical picture of grid consumption, enabling energy balance reporting and import-cost tracking directly inside your ModbusCloud portal.
- Protocol
- Modbus RTU
- Connection
- RS485
- Registers
- 4, read only
- Brand
- FoxESS
- Last updated
Registers (4)
4 read, 0 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| power_a | W | Read | |||
| power_b | W | Read | |||
| power_c | W | Read | |||
| energy | kWh | Read |
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Use cases
- Monitor per-phase grid active power on R, S, and T to detect load imbalances across the three phases.
- Track cumulative grid-import energy over time to calculate monthly electricity costs and report consumption trends.
- Alert on unexpected surges in phase power to identify malfunctioning loads or wiring faults in the installation.
- Compare phase power readings during peak tariff hours to verify that the inverter is correctly offsetting grid draw.
- Verify that total grid-import energy resets and accumulates correctly after firmware updates or inverter restarts.
Installation
Enable Modbus communication on the FoxESS H3-Pro or H3-Smart inverter by navigating to Settings, then Communication, and confirming the Modbus slave ID is set to 247 (default).
Connect the ModbusCloud Gateway to the inverter's EMS 485A/B pins on the COM connector using a shielded twisted-pair cable; match A to A and B to B terminals and keep the run as short as practical.
In the ModbusCloud portal, add a new gateway, then open the template library, import the FoxESS H3-Pro/Smart Series Hybrid Inverter (grid) template, and assign unit ID 247 to match the inverter's slave address.
Trigger a manual poll in the portal and spot-check the power_a register (address 38816); a non-zero signed value in watts confirms communication is working correctly.
Things to watch for
All three phase power registers return zero. What is wrong?
Confirm that the Meter1/CT1 meter or CT clamp is physically connected and that its connection state register (address 38801) reads 1 (Connected). If the meter is disabled in the inverter's Feature Parm menu, the phase power registers will report zero even though Modbus communication is active.
Values seem ten times too large. Is there a scaling issue?
The FoxESS Modbus protocol documents a gain of 10 for registers 38816, 38818, and 38820, meaning raw register values are in units of 0.1 W. The OpenEMS template stores the int32 value directly without applying this divisor, so verify your display layer is not double-scaling. Treat the raw value as watts if readings appear plausible.
The gateway connects but no data appears for any register.
The FoxESS H3-Pro and H3-Smart require RS485 access via the EMS 485A/B pins on the large COM connector, not the Meter485 port used by older H3 models. Also confirm the baud rate is set to 9600, 8 data bits, no parity, 1 stop bit, which is the FoxESS default RS485 configuration.
The energy register reading dropped suddenly. Is data reliable?
Register 39617 is a cumulative uint32 counter. A sudden drop usually indicates a uint32 rollover or an inverter restart that reset the internal counter. Cross-reference with daily totals stored in your ModbusCloud portal history to reconstruct true accumulated values and set a baseline after any reset event.
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