Activates when utility power fails completely or fluctuates beyond the AVR's corrective range.

Because the inverter is always active, there is zero transfer time when the power fails.

When voltage falls outside a specific range or fails entirely, a mechanical switch transfers the load to the internal battery and inverter.

Better protection against brownouts than Off-line models, with a reduced frequency of battery use, extending battery life. 3. On-line (Double Conversion) Scheme

The most advanced scheme, designed for critical equipment like servers and medical devices.

An evolution of the standby UPS, often used for small office networks.

Depending on the architecture of the UPS, there are three primary operational schemes: , Line-Interactive , and On-line (Double Conversion) . 1. Off-line (Standby) Scheme This is the simplest and most common scheme for home PCs.

The UPS passes utility power directly to the connected equipment while simultaneously charging the battery.