The full power design now lives in Hardware. That page documents the dual 20A circuits, dual UPS units, current single PDU, generator hookup, and the planned ATS upgrade. This page is intentionally short so there is one source of truth for physical power layout.
The operating priority is to keep routing, switching, DNS, storage, and management access online through short interruptions. If the outage is longer, the UPS units provide the transition window and the generator hookup becomes the next continuity layer. Noncritical services can remain down until utility or generator power is stable.
The next planned power improvement is an ATS fed by both UPS units. That should make selected rack loads less dependent on a single UPS path and improve maintenance/failure handling.