What a 40kVA UPS is for
A 40kVA UPS (40 kW at unity power factor) protects growing server rooms, mid-size comms hubs and industrial control systems. Three-phase supply is standard, and modular architecture starts to make sense for redundancy and future growth.
Three-phase and load balancing
Above 20kVA, three-phase UPS are the norm. They distribute power evenly across phases and integrate with three-phase building supplies. Balancing the load across all three phases is essential — an unbalanced load reduces usable capacity and can trip the UPS.
Modular vs monolithic at 40kVA
A monolithic 40kVA UPS (Sentryum S3T, one self-contained cabinet) is simpler and cheaper upfront. A modular frame — Sentryum Rack or Legrand TriMOD HE — lets you add hot-swappable modules for N+1 redundancy and pay-as-you-grow capacity. Choose modular if you expect growth or want downtime-free maintenance.
Runtime, redundancy and models
Internal batteries give minutes; external cabinets or lithium banks extend runtime to 30–60 minutes or more. Build N+1 with a modular frame or by paralleling two monolithic units. Strong 40kVA options include the Riello Sentryum S3T, Multi Power and Legrand TriMOD HE. Use the UPS Finder for a tailored recommendation.
Frequently asked questions
Is a 40kVA UPS single or three-phase?
Three-phase is standard at 40kVA, to balance loads and integrate with three-phase building supplies.
Modular or monolithic 40kVA UPS?
Monolithic is cheaper upfront. Modular (Sentryum Rack, TriMOD) adds hot-swap modules, N+1 redundancy and pay-as-you-grow capacity.
How long will a 40kVA UPS run at full load?
Minutes on internal batteries; external battery cabinets or lithium banks extend this to 30–60 minutes or more depending on load.
Can I parallel two 40kVA UPS?
Yes. Sentryum parallels up to 8 units and TriMOD up to 160kW, so you can build N+1 or capacity configurations.