Modbus adapters - external inverter

[Kosymodo]

Hey folks

Just had a KH8 inverter installed as part of my solar install. I've been a Home Assistant dabbler for a while now, and have already got the basic stats of the solar system pulling through into HA. I'm keen now to use a proper Modbus adapter, to reep the benefits. However, the inverter is externally located, and so I'm wondering whether any of the adapters are weather-proof?

Assuming there is a suitable adapter available, I must admit that the instructions on how to wire it up are somewhat daunting, even though I'd class myself as technologically savvy!

Any advice would be very gratefully received

[Dave Foster]

You don’t need to have the adapter near the inverter (although you could have it outside in an IP65 enclosure) - the RS485A/B pair is a differential balanced pair and as long as you use good quality cable (cat5/6) you can run a cable from the meter/ct connector (pins 3 &4 RS485A/B) to a suitable location inside the house - preferably near your home network or the home assistant itself.

If you use a USB adapter it would need to be plugged in at the home assistant cpu itself and the cable would terminate there, or you could use a waveshare module which connects to your home network using ethernet (there is also a wifi version) again the RS485 cable is terminated on the device.

It can feel a bit daunting to remove the meter/ct connector from the inverter, open it and pop in a new cable - the CT (or meter) will also be wired to it and the cores have a habit of coming out of the pins when you work inside there but again the pinouts are well documented. Before you remove the meter/ct connector you must turn off the inverter - the moment the meter/ct connector is removed it will stop and throw an error anyway.

I’m guessing you’ve seen the wiki on the home assistant integration as there are a lot of hints and tips on there https://github.com/nathanmarlor/foxess_ ... ring-Guide

[Kosymodo]

Thanks for your reply Dave, very helpful.

OK, so I need to run am ethernet cable up from the inverter, through the soffit and into the loft where my HA is located. Ideally I'll ask the installers to do this tomorrow when they return to install remaining panels. However, I've no external ethernet cable spare, and Amazon can't get it to me on next day delivery, so that might ruin that plan...

Yeah I saw the wiki, and whilst it's helpful, it doesn't remove the fear of messing around with the inverter connection

[WyndStryke]

How about getting hold of a spare connector, CT clamp, and so forth, and assembling an entirely new connector that you can just swap over? It removes the element of risk.

The CT clamp is available for sale at some distributors, fairly cheap, but the connector might be harder to get hold of. I don't know where to get one of those.

[Kosymodo]

Hmmm, might be worth looking into! Good idea