What safeguard exist within an Online UPS to protect against the loss of power in the unlikely event of an inverter failure or overload?
Online UPS systems usually incorporate a Static / Electronic Bypass Switch. This facility improves the reliability of the installation as it ensures that in the unlikely event of an inverter failure / UPS malfunction , or overload, the load is automatically transferred, without interruption, back to the mains supply. Once the event has been cleared the Bypass switch should then re-engage inverter output online.
Most larger online UPS also incorporate a second Bypass facility – The Manual Bypass Switch. This switch allows the load, without interruption, to be manually transferred to mains so that the UPS system may have maintenance and repair work carried out without requiring the machine to be powered down.