@Solla-topee Hi. Thanks for the response. So can I then assume that there is no solution to the problem? The PLC's are not plugged into the UPS and the UPS does not run anything other than the fibre...

I have been using the AV500 powerline adapters for years without any issue. I live in South Africa and we are experiencing load shedding from our electricity supplier. I bought a UPS/inverter to...