FAQ > Voltright > AVR 3S4x1200-22-BCDMYZ
Is the AVR set to 220 or 230 or 240V nominal?
The Automatic Voltage Regulators (AVRs) are normally set to 220V. It can operate normally and safely with 230V or 240V. In fact, the output will be reduced to 220V +/-4% which will be a better operating voltage for most electrical/electronic equipment and can additional save energy with certain type of equipment.
Do I Need To De-rate an AVR When Installed At High Altitudes?
Yes. A fan cooled Automatic Voltage Regulator (AVR) must be de-rated at altitudes above 2000 meters.  At 2000 meters, de-rate by 18%.  and then by 9% for every 1000 meters. So At 3000 meters, de-rate by 27% and so on