UPS
UPS covers battery backup from desk units to data center systems. APC models run from the Back-UPS Pro BR700G through Smart-UPS C, SMT, SMX and older SUA units to SRT online UPSs up to 5kVA, in tower and rack forms with 120V and 230V outlets. Liebert's PSI5, GXT5 and ITA2 units reach 10kVA, and CyberPower, Tripp Lite SmartOnline and HP UPSs round it out. APC step-down transformers and battery packs for these systems are listed too.
UPS: 697 products
Buying guide
Choosing a UPS
VA and watts
Size by the watt rating against your measured load, with headroom. The VA rating is always the larger number.
Topology
Online double-conversion units condition power continuously; line-interactive units are a common, efficient choice for server closets.
Rack or tower
Rack-mount units take 1U to 3U or more of rack space; towers sit on the floor or a shelf.
Runtime and management
External battery packs extend runtime. A network management card lets servers shut down cleanly on a long outage.
Plug type
Match the input plug (NEMA 5-15P, 5-20P, L5-30P, L6-30P) to the outlet you have.
UPS
Frequently asked questions
How long will a UPS run my equipment?
It depends on the load and the battery capacity, and the relationship isn't linear: halving the load more than doubles runtime on most units. Manufacturers publish a runtime chart for each model.
Can I plug a laser printer into a UPS?
Not into the battery-backed outlets. A laser printer's fuser draws large current spikes as it heats, which can overload the UPS. Use a surge-only outlet or a separate protector.
Will a UPS work with a backup generator?
Yes, but generator power can drift in frequency, which makes some line-interactive units switch to battery repeatedly. Online double-conversion units handle generator power best.
