What a 20kVA UPS is for
A 20kVA UPS (20 kW at unity pf) protects medium server rooms, larger comms hubs, industrial control systems and mid-size commercial installations. At this size, three-phase supply and proper switchgear planning become standard, and redundancy moves from optional to recommended.
Three-phase is the norm
Above 10–20kVA, three-phase UPS are the standard — they balance loads across phases, carry more power efficiently and integrate with three-phase building supplies. The Riello Sentryum S3T and Legrand TriMOD HE both cover 20kVA in three-phase, with unity power factor and online double-conversion.
Modular vs monolithic
At 20kVA you can choose a monolithic UPS (one self-contained unit, lower upfront cost) or a modular UPS (hot-swappable power modules, N+1 redundancy, pay-as-you-grow). Modular systems like Sentryum Rack (20kVA modules) and TriMOD let you start at 20kVA and add capacity without replacing the frame — ideal if growth is expected.
Redundancy and runtime
Build in N+1 redundancy with a modular frame, or parallel two monolithic units. For runtime, internal batteries give minutes; external cabinets or lithium banks extend to hours. Plan a maintenance bypass and proper cooling — a 20kVA UPS at 96% efficiency still produces heat that must be removed. See the Sentryum range and Legrand range.
Frequently asked questions
Is a 20kVA UPS single or three-phase?
Three-phase is standard at 20kVA, to balance loads and integrate with three-phase building supplies. Some single-phase 20kVA models exist but are less common.
Modular or monolithic 20kVA UPS?
Monolithic is cheaper upfront. Modular (e.g. Sentryum Rack, TriMOD) adds hot-swap modules and N+1 redundancy and lets you grow without replacing the frame.
Can I parallel two 20kVA UPS for redundancy?
Yes. Sentryum parallels up to 8 units and TriMOD up to 160kW, so you can build N+1 or capacity configurations at 20kVA and above.
What runtime does a 20kVA UPS give?
Minutes on internal batteries; external battery cabinets or lithium banks extend this to 30–60 minutes or more, depending on load.