The Vertiv Liebert PSI5 1kVA UPS is designed to protect and extend the life of your electronic devices in school, home and office. This 1U rack mount UPS offers cost-effective protection from downtime and damage caused by power outages, brownouts, sags, surges or noise interference. Automatic Voltage Regulation (AVR) extends battery life and safeguards critical equipment. Voltage regulation is from 83 to 159 VAC without using the battery.