A UPS provides backup power to protect your equipment from damaging spikes, surges, sags and outages. It can also prevent work-in-progress from being lost due to a power outage and give you time to shut down hardware or save data without losing valuable information. Depending on the UPS technology and size, it can be used to protect anything from a single computer to an entire data center.
UPS systems are rated in volt-amperes (VA) to indicate the amount of power they can provide to a load, with a VA range from 300VA up to 5 kVA. Most UPS systems are rated for a specific load, and the output can be adjusted to match that load’s wattage by changing the internal settings.
Using an inverter, a UPS converts AC utility power into DC power to feed the batteries and connected loads. This avoids a transfer switch, making it ideal for applications with minimal power fluctuations. The sags and surges that cause problems with most power supplies are clipped, boosted or eliminated by online UPS systems to ensure a clean output. Online UPS technologies provide high levels of protection at reasonable operating costs and are typically reserved for environments with the most sensitive equipment, such as data servers or intensive care units.
A line-interactive UPS system has a 4-6 millisecond break in power when transferring to battery backup, providing less disruption to the connected equipment and reducing electric consumption. The UPS also regulates voltage and balances under and over voltages to avoid frequent switching to battery which would drain the reserve power intended for an outage and reduce the battery lifespan.