Offline/Standby Modified Sine Wave UPS
Offline UPS works the simplest among different types of UPS. Its functions are mainly surge protection and battery backup. When the mains power is stable, offline UPS runs bypass mode and the device is directly connected to the mains power. In case there is a sudden blackout, offline UPS will mechanically switch from the mains power to DC-AC inverter output (from battery) in less than 25 milliseconds in order to avoid equipment shutdown. The backup time varies depending on the capacity of the battery as well as degree of loading.