Engineering notes
Sizing UPS VA: add real watts, not nameplates in a pile
Add NVR, switch and DDC watts at infrared and at charge. Times 1.25. Convert to VA with the power factor.
The switch nameplate says 370 W. That is the PoE ceiling, not what every job draws. At night the cameras turn infrared on just as mains die — the peak of recorder plus PoE can top a “comfortable” 1.5 kVA. Make two columns: steady, and peak (infrared, charger, disk spin-up).
Add watts, times about 1.25, convert to VA if the file quotes VA (divide by power factor, often 0.8 or 0.9). Runtime: internal batteries or an external pack. Some “3 kVA” units hold three minutes at full load — read the curve, not the flyer.
Send the list of kit in the cabinet. Rack UPS