What is the difference between off-line, line-interactive, and on-line ups systems ?
Off-line ups systems are the most basic type of ups system and are typically used for home PC’s and workstations. They monitor power quality, and switch to battery when power quality falls out of acceptable range or when a power outage occurs. Line interactive ups systems are often used on PC’s and file servers, and are a middle grade of ups system. They monitor power quality and have boost/buck circuits to keep power quality in check. When power quality goes too far aout of range or a blackout occurs, they switch to battery. True on-line double conversion ups systems use a device called an inverter to re-create power to isolate the equipment from incoming power. The inverter is constantly converting power from AC to DC and back to AC again. The battery is wired in parallel to the inverter, so when an outage occurs, there is a seamless transition to battery. These systems range in size from 700 VA to 500 kVA and power everything from sensitive lab equipment to corporate datacenters.
