Damage so far: 1 @amazonDE USB-charger, 1 240V/USB outlet, 1/...
The 3000VA @APCbySchneider UPS, protecting all computing equipment, survived. 2/2
The @Zeversolar 3860 problem was cabling; one of the connectors had come loose, dropped to the ground, got moist and had a bit of DC current earth leaking.
The safety mechanism in the converter found this, hence Error Code 38: zeversolar.com/service/faq/ 1/2
All connectors have been re-fastened on 60 cm height. If this ever happens again, I know what to check first.
2/2