UPS connection at home can keep a modem, cameras, computer or boiler running during a power outage. Capacity and wiring must be chosen correctly.
The load, socket, cable, breaker and panel condition should be reviewed. A UPS will not fix a loose contact or an overloaded old circuit.
A UPS is usually useful for modems, routers, cameras, computers, monitors and boiler control electronics. High-power heaters and appliances are not suitable for a normal UPS.
If the UPS gets hot, beeps often, trips a breaker or the socket darkens, the line and load should be inspected.