Sofar 250-350 kW, 800 V with GridZeno.

Sofar 250-350 kW, 800 V on the compatibility list, updated 31 October 2026.

• Live overview of solar, consumption and gridAll subscriptions · Grid and consumption require an energy meter at the grid connection.
  Works
• Battery state of chargeAll subscriptions · requires a battery · The grid inverter has no battery.
  Not possible
• Stop selling at negative pricesSmart and Pro · Requires the installer to have turned export limiting on in the inverter. GridZeno only lowers a limit that's already set. Also requires inverter firmware from 2022 or later.
  Works
• Charge from the grid when power is cheapSmart and Pro · requires a battery
  Not possible
• Discharge the battery when power is expensivePro · requires a battery
  Not possible

Works: tested and measured on real hardware.

A grid inverter without a battery: GridZeno reads it and lowers the export limit at negative prices.

Battery

None. The inverter is a grid inverter without a battery, so there's nothing to charge or sell from.

Stop selling at negative prices

The inverter's export limit is set quarter by quarter by the selling price, but only where the installer has turned export limiting on. GridZeno only lowers a limit that's already set and never turns it on or off.

What it requires

Inverter firmware from 2022 or later for the export limit, and an energy meter at the grid connection for grid and consumption.

Manual

When the control is on Manual, the dongle changes nothing on the inverter. It reads, and if GridZeno has changed something, it puts the inverter's own settings back, including your own charge limits.

The serial number in holding 0x0445 with the code R1: 255KTL-HV.

How it differs from its neighbours

• Sofar KTLX 25-136 kW: The KTLX from 25 to 136 kW has the codes S3, S4 and Q1 and is read and limited the same way.

For the installer: the registers

What the dongle uses over Modbus, if you want to follow along or troubleshoot. Don't change the registers yourself while control is set to Automatic.

Serial number

0x0445, and characters 17-20 of a 20-character serial number in 0x0470-0x0471.

Export limit

0x1023 and 0x1024 in 100 W. Only in the installer's modes 1 and 2; in modes 3 and 4 and in parallel operation it's only read.

Rated power

0x06ED in 0.1 kW.

Fault codes

30 words in 0x0405-0x0416 and 0x0432-0x043D.

From the dongle's firmware and our notes on each inverter, not from the datasheet.

Wires in the inverter's terminal plug. Approx. 30 minutes.

Port

COM (16-pin connector, RS485 Modbus/DRMs)

Pin

A at pin 1 (RS485 A), B at pin 3 (RS485 B), GND at pin 7 (GND.S)

Where

On the underside of the inverter, by the USB port. The same connector is used for DRM, so there may already be wires in it.

See the full installation guide for Sofar 250-350 kW, 800 V

GridZeno Dongle for Sofar 250-350 kW, 800 V

This one works.

Sofar 250-350 kW, 800 V is the inverter GridZeno has been tested on. Check that your model is under 250/255KTL-HV, -HV-PRO, 255KTL-HV-TRO and 250-350KTLX0/X1. If it still doesn't suit you, you have 100 days' free return.