Growatt WIT 29.9-50K-XHU with GridZeno.

Growatt WIT 29.9-50K-XHU on the compatibility list, updated 31 October 2026.

• Live overview of solar, consumption and gridAll subscriptions
  Works
• Battery state of chargeAll subscriptions · requires a battery
  Works
• 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.
  Works
• Charge from the grid when power is cheapSmart and Pro · requires a battery · Choose WIT over 15 kW as the model when you set up GridZeno. The WIT option only covers 4-15 kW.
  Works
• Discharge the battery when power is expensivePro · requires a battery · Choose WIT over 15 kW as the model when you set up GridZeno. The WIT option only covers 4-15 kW.
  Works

Works: tested and measured on real hardware.

The dongle controls the inverter in the same way as our own WIT 15K-HU and always sets the inverter's own mode back afterwards.

Charge from the grid

Battery First with the plan's target as the stop state of charge. When the target is reached, the battery stands idle for the rest of the block.

Hold the battery

The IDLE mode: the battery neither charges nor discharges while the house uses solar and grid.

Sell from the battery

A time-limited command in Growatt's VPP protocol. The dongle renews it while the sale lasts and removes it afterwards.

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

Choose WIT over 15 kW as the model when you set up GridZeno. The WIT option only covers 4-15 kW.

The rest of the time

The inverter's own mode. The dongle saves it before it switches the first time, and sets it back after each block and after a restart.

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 type code 5601. The Home Assistant integration Growatt_ModbusTCP calls 5601 a WIT 29.9-50K-XHU after a register scan; Growatt's VPP protocol V2.01 calls it a WIT 100KTL3-H. Both are controlled as WIT above 15 kW.

Model in GridZeno

WIT above 15 kW.

What the dongle reads

With the WIT map: the sun also from PV3 and PV4, the grid from 8081-8084 and battery cluster 3 from 31410.

How it differs from its neighbours

• Growatt WIT 17-25K-HU and 4-25K-XHU: Up to 25 kW the XHU series has no type code of its own and is found by its rated power. RS485-IN is behind the lower cover.
• Growatt WIT 50-125K-XHU: From 50 kW the RS485 port is in the COM connector on the right side, also with pins 7 and 8.

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

Network cable with RJ45 plug. Approx. 25 minutes.

Port

RS485-1 (in COM1)

Pin

A at pin 8 (RS485_3A), B at pin 7 (RS485_3B), GND at pin 2 (GND.S)

Where

On the underside, between the MPPT inputs and the USB port. COM1 has nine RJ45 ports under a waterproof cover with two cable glands: BMS1, RS485-1 and RS485-2 at the top, BMS2, PARA-IN and PARA-OUT in the middle, BMS3, METER and DI at the bottom. RS485-2 has the same pins.

See the full installation guide for Growatt WIT 29.9-50K-XHU

GridZeno Dongle for Growatt WIT 29.9-50K-XHU

This one works.

Growatt WIT 29.9-50K-XHU is the inverter GridZeno has been tested on. Check that your model is under WIT 29.9K, 30K, 36K, 40K and 50K-XHU, and that a battery is fitted if you want the battery controlled by the electricity price. If it still doesn't suit you, you have 100 days' free return.