[RA2lover]

I own a Guangzhou Sanjing R5-8K-S2 inverter that had issues shortly after installation where it was generating far less power than expected.

The web telemetry panel had multiple gaps throughout the day where energy generation dropped to 0, but having datapoints logged every 10 minutes didn't give out enough information to determine why that was happening.

It also had a current status endpoint which updated every 10 seconds. I wrote a python script to log those updates into a file, and eventually discovered the inverter was shutting down itself and waiting 5 minutes every time it found its grid voltage to be greater than 241V.

Installer wanted utility to lower the house's grid transformer tap, but needed authorization from Utility, who declined claiming it was already on the lowest tap possible. Cynically, i think they declined because lowering further would lower grid voltage at night below minimums they're contractually required to maintain.

Tried going into the manufacturer's website to see if a firmware update could solve this. Couldn't find firmware updates, but i did find a manual for their local monitoring app, including a password for installer-only settings, set to "123456".

The app doesn't include any functionality to change said password to something else, so i assume it's hardcoded. There was one change i could still legally do without violating anything - raising the grid shutdown threshold voltage from 241 to 242V. This change did get reflected in subsequent logs, so the settings panel is functional. I could technically increase that further (to a maximum of 275V), but that would expose me to liability.

Parents suggest contacting the inverter's distributor for support, and they asked for a password i was never given. Apparently the manufacturer is suppopsed to create accounts for installers/distributors buying directly from them, and i somehow bypassed that process when creating an account for myself, without even realizing it.

Some more clarification later, it turns out they can still remotely access the inverter with its serial number. After doing so, they "fixed" the issue without explaining how. Checking the installer settings interface, it turns out they just increased the grid overvoltage shutdown threshold to 275V right off the bat.

At least i got them on record saying they did that, so i'm technically in the clear. Still, having that kind of access was scary enough to want to make me disconnect the inverter from the internet.

Turns out its warranty (which only expires in 2036) has terms requiring it to stay connected to the internet. That's enough time to trigger WW3 and a resulting horus scenario (https://horusscenario.com/).

Until then, the best i can do is to throttle the inverter's internet connection to something like 10kbps, which isn't enough to prevent someone persistent enough from uploading new firmware.

Stories like this make me reconsider keeping it connected. I'm surprised we haven't seen inverter ransomware yet.

[buzer]

> Turns out its warranty (which only expires in 2036) has terms requiring it to stay connected to the internet.

Does it define any requirements for the internet connection? What if the connection latency was, let's say, 1 week?