FAQs - Line Interactive UPS
Line interactive UPS information including form factors, power protection levels, battery runtimes and communications features.
A line interactive UPS is a Voltage Independent (VI) uninterruptible power supply as defined by BS EN 62040. The UPS has a built-in automatic voltage regulator (AVR) or automatic voltage stabiliser (AVS) to respond to sags, surges and brownouts, an EMC/Transient filter for spikes and electrical noise and an inverter which will generate a sinewave or pseudo sinewave output when the mains power supply fails.
A line interactive uninterruptible power supply has a built-in automatic voltage regulator (AVR) that can step the incoming mains power supply voltage up or down using as a series of taps or relays. If the mains power supply voltage or frequency fails outside a preset threshold window the supply is seen to have failed and the inverter section switches into circuit to supply power to the load from the battery set. The inverter ‘inverts’ the DC (direct current) supply from the battery set to AC (alternating current) to support the connected loads.
In a line interactive uninterruptible power supply the inverter section is typically energised but not connected to the load. The load is connected to the inverter when the mains power supply fails via a relay switch. There can be a small break in output supply of 2-4milliseconds but this is well within the energy storage capacitance of the switch mode power supply (SMPS) in modern electronic devices like servers, computer, bridges, routers and storage devices.