Should your voltage degrees are unstable (ie: power stays on, but the actual voltage level may differ quite a bit through the 220V common), then I believe that's the type of scenario wherever an AVR is useful. Uninterruptible power supply (UPS) models aren't only for info centers and overly careful https://cruzycbay.azzablog.com/33947120/uninterruptible-power-supply-calculator-can-be-fun-for-anyone