Line-interactive UPS units are backup power supplies that protect computers, network equipment and NAS drives from power cuts and voltage fluctuations. Our range includes tower, desktop and rackmount models, with APC, Eaton, BlueWalker and CyberPower supplying the largest number of them.
How to choose a line-interactive UPS
Power rating. Size the UPS by watts rather than VA alone, because watts show how much load it can actually carry. Add up the consumption of everything you plan to connect and leave a margin of at least 20-30%. A desktop PC with a graphics card needs far more than a router and a NAS.
Topology. A line-interactive UPS adjusts the mains voltage automatically and switches to the battery only when the power fails or the voltage drifts too far. Our range also includes simpler standby (offline) models and a few double-conversion (online) units for more sensitive equipment.
Output waveform. Sine wave or pure sine wave output suits most equipment, especially PC power supplies with active PFC. Stepped or simulated sine wave on simpler models can cause problems on battery, so choose pure sine wave for a boiler pump or other sensitive devices.
Outlets and connectors. Most models in our range have 4, 6 or 8 outlets, and there are 2 and 9 outlet versions too. Type F (Schuko) or type E outlets take ordinary household plugs, while C13 and C19 connectors are used for servers, switches and rack equipment.
Form factor. Tower and desktop cases sit under a desk or beside the equipment, while rackmount models fit a 19-inch cabinet. Some models can be used either way (Rackmount/Tower).
Brands in this category
- APC: part of Schneider Electric and known for its Back-UPS and Smart-UPS series for home and business use.
- Eaton: a power management company that took over the Powerware brand, which is why Eaton Powerware models appear in our range.
- BlueWalker and PowerWalker: PowerWalker is a BlueWalker group brand, and its VI series consists of line-interactive UPS units.
- CyberPower: known for line-interactive models with pure sine wave output, including rackmount versions.
- Green Cell: a Polish manufacturer specialising in batteries and power solutions.
Also in our range: Conceptronic, Qoltec, Roline and Energenie.
Frequently asked questions about line-interactive UPS
What is the difference between a line-interactive and an online UPS?
A line-interactive UPS passes mains power through with automatic voltage regulation and switches to the battery as soon as the power fails, while an online (double-conversion) UPS reprocesses the power all the time. An online unit gives the steadiest supply with no switchover, but it is usually larger and noisier. For homes and small offices, line-interactive is normally enough.
What UPS power rating does a computer need?
Choose a UPS whose wattage is at least 20-30% above the total load of everything connected. If a PC and monitor draw about 300 W, look for a UPS rated at 400-450 W or more. For gaming PCs, consider the peak load of the graphics card and processor.
Can a line-interactive UPS power a heating boiler pump?
Only if it has pure sine wave output and meets the boiler manufacturer's requirements. Stepped or simulated sine wave can cause noise or put extra strain on the pump motor. Check the pump's power and starting current before buying.
How often should a UPS battery be replaced?
Usually every 3-5 years, though it depends on temperature, load and how often the power fails. Batteries wear out faster in a hot room. If the UPS reports a worn battery or runs for only a very short time, it is time to replace it.
