KH inverter USB to Modbus connection query

[fatfairy]

I have seen on the forum the strong advice that when using the H1 inverter one should avoid the USB port connection for attaching the Modbus. My install will have the KH 8kwh inverter which also has a USB connection. Does the same advice apply to this model regarding the limitations the USB connection imposes on parts of the data transfer. The manual states that the terminal is WiFi / 4G /USB if that is anything to go by. Many thanks for any thoughts on this.

[Dave Foster]

Yes you should not use the USB port for any other purpose than it is designed for, even on earlier generation inverters that did have a spare USB port - these were only low power devices and not suitable for supplying power to modbus adaptors long term (unless extremely low power)

On the later generation inverters including the KH there is only a single USB port and you will need a wifi (or lan) datalogger to be plugged in which is used to send data back to the Fox cloud, also as importantly for remote diagnostics, DST clock changes and firmware updates.

[fatfairy]

Thanks for that info Dave. So if I have got it right only connect to the Meter/CT/RS485 port on the inverter for HA access.

[Dave Foster]

Thanks for that info Dave. So if I have got it right only connect to the Meter/CT/RS485 port on the inverter for HA access.

Yes that’s right, it’s a 2 wire balanced connection so it doesn’t need a ground or any power, just an A/B pair.
On the KH inverter you will find RS485A on pin 4 and RS485B on pin 3

[fatfairy]

Thanks again