Draw every powered hop
Start at the ISP handoff: ONT or modem, router, required switch or access point, controller, Thread border router and the endpoint. Mark power adapters and PoE sources. Backing up the router while leaving the ONT or PoE switch unpowered breaks the chain. Include a battery-powered device's hub and the phone used for local control where those are required.
Plan runtime from the real load
Measure or obtain the load for the complete selected chain, then use the exact UPS manufacturer's runtime curve. VA is not a duration, and dividing advertised battery capacity by one device's adapter rating does not establish usable runtime. For DC units, voltage, polarity, connector and current rating must match every powered device. Do not improvise mains wiring or use a plug adapter to assume electrical compatibility.
Record one fallback for each essential routine
For entry, retain the lock's documented physical or local method and keep it accessible. For pet feeding, distinguish a saved local schedule from app access and confirm the exact model's battery behavior. PETLIBRO's PLAF103 documentation describes emergency battery operation with restricted Wi-Fi functions; that is not a claim about every feeder. Keep a person and a non-automated care plan available.
Make a recovery checklist
For a non-essential test, first interrupt only the internet uplink while leaving local equipment powered; restore it before testing another layer. Record which controls remain available and which notifications disappear. Check clock, saved schedules, recording and reconnection after restoration. Do not deliberately interrupt security, heating or caregiving functions that people are relying on.