kVA (Apparent Power)

kVA, or kilovolt-amperes, measures the apparent power an alternating-current load pulls from the supply. It is the vector sum of real power (kilowatts, the energy that does useful work) and reactive power (kilovolt-amperes reactive, or kVAR, which sustains the magnetic and electric fields in the load). The classic analogy is a glass of beer: the liquid is real power (kW), the foam is reactive power (kVAR), and the full glass is apparent power (kVA).

Why apparent power matters for a Hashcenter

Utilities, transformers, generators, and PDUs are rated in kVA, not kilowatts, because their conductors and windings must carry the total current regardless of how much of it does useful work. A switch-mode ASIC power supply with active power-factor correction (PFC) keeps its kVA close to its kW draw, so a 3,500 W miner presents roughly 3.5 kVA. Without PFC, the same load could demand noticeably more kVA, forcing you to oversize wiring, breakers, and any generator or UPS feeding the rack.

Estimating your kVA budget

To size service equipment, sum the kVA of every miner, PSU, and ancillary load, then add headroom for inrush and the 80% continuous-load derate. Dividing real power (kW) by the fleet's average power factor gives a working kVA figure. Getting this right prevents nuisance trips and avoids paying for transformer capacity you cannot actually use.

kVA sits at the center of mining electrical planning alongside kVAR (reactive power) and the load factor of your site. Understanding all three keeps your power bill and your panel honest.