A UPS (uninterruptible power supply) sits between the wall socket and your equipment. When the mains drops or spikes, its battery takes over instantly so servers, switches and routers keep running or shut down cleanly.
Sizing it properly
Add up the power draw of everything you plan to connect and leave room to grow. Then decide how many minutes of runtime you need: enough to ride out short cuts, or enough to shut down safely while a generator starts.
What to connect
- Servers and shared storage
- Network switches, routers and firewalls
- Desktop computers that hold unsaved work
- Security recorders and access control controllers
Keep large laser printers off a UPS, as they draw heavy bursts of power. Finally, plan to test the unit regularly and replace batteries when they weaken.