Xtreme Power X90-5S vs Vertiv Liebert EXL S1
A 50–350 kW modular 480V UPS comparison — the hot-swappable, high-density X90-5S against the Vertiv Liebert EXL S1 (250–400 kW). The X90-5S is a scalable, modular online double-conversion UPS that protects critical data and equipment, available from 50 kW to 350 kW.
Integrated hot-swap modular vs. conventional modular
The Xtreme Power Conversion X90-5S is a scalable, modular online double-conversion 480V UPS that efficiently protects critical data and equipment from power problems, available in capacities from 50 kW to 350 kW.
The Vertiv Liebert EXL S1 is an online double-conversion UPS deployed across data-center and large-facility environments, available from 250 kW to 400 kW.
Both platforms provide unity power factor output. The key differences are entry capacity and pay-as-you-grow scaling, power-module serviceability, altitude rating, footprint, and power density — compared below. The X90-5S modular design scales from 50 kW to 250 kW (5 × 50 kW modules) or 70 kW to 350 kW (5 × 70 kW modules).
How the two architectures differ
The Xtreme Power X90-5S is a scalable, modular online double-conversion 480V UPS built from hot-swappable 50 kW and 70 kW power modules, scaling from 50 kW to 350 kW within a single high-density cabinet. Power modules can be added or replaced while the system continues to protect the load.
Because power and battery modules are front-accessible and hot-swappable, capacity expansion and module service do not require transferring the load to unprotected utility power — an architectural difference that affects serviceability, uptime risk, and electrical-room planning.
Per the supplied comparison, the Liebert EXL S1 power modules are not hot-swappable, and adding capacity or redundancy requires an entire additional UPS plus a tie cabinet. The X90-5S scales in-cabinet — its 280 kW configuration upgrades to 350 kW, or to 280 kW N+1 redundancy, by adding a 3U 70 kW power module, with no additional footprint. The X90-5S also holds full capacity to 5,200 ft, where the EXL S1 derates above 3,300 ft.
X90-5S vs Vertiv Liebert EXL S1
| Feature | Xtreme Power X90-5S | Vertiv Liebert EXL S1 | Advantage |
|---|---|---|---|
| Capacity | 50 kW to 350 kW | 250 kW to 400 kW | Both platforms provide unity power factor output. The X90-5S modular design enables a pay-as-you-grow approach from 50 kW to 250 kW (5 × 50 kW modules) or 70 kW to 350 kW (5 × 70 kW modules) — a far lower entry capacity than the EXL S1’s 250 kW. |
| Modular / scalable design | Yes — modular and scalable | No | The X90-5S 280 kW capacity can be upgraded to 350 kW, or configured as 280 kW N+1 redundant, simply by adding a 3U 70 kW power module — no additional footprint required. Capacity or redundancy can be added to the Liebert EXL S1 only by adding an entire additional UPS and tie cabinet. |
| Hot-swappable power modules | Yes — hot-swap power modules | No | X90-5S power modules can be added or replaced at any time, quickly and without powering the system down. The Liebert EXL S1 does not offer hot-swappable modules. |
| Altitude | Full capacity to 5,200 ft | 3,300 ft | The Liebert EXL S1 derates above 3,300 ft above sea level; the X90-5S provides full capacity up to 5,200 ft. |
| Footprint | 9.2 sq ft — 31.5″W × 42″D × 79″H | 12.8 sq ft — 51.3″W × 36.0″D × 79.1″H | The Liebert EXL S1 is about 20″ wider and occupies a roughly 40% larger footprint than the X90-5S. |
| Power density | Up to 38 kW per sq ft | Up to 31.2 kW per sq ft | The X90-5S delivers higher power density than the Liebert EXL S1 — up to 38 versus 31.2 kW per square foot. |
| Warranty | 2 years on-site with factory start-up | 1 year on-site with factory start-up | Xtreme Power includes factory start-up and a 2-year parts & labor warranty; the Liebert EXL S1 includes a 1-year parts & labor warranty. |
Vertiv Liebert EXL S1 figures are shown as supplied and are unverified; confirm against current manufacturer documentation. X90-5S figures per the X90-5S datasheet.
Where the X90-5S leads
- Lower entry, pay-as-you-grow. Scales from 50 kW (5 × 50 kW modules to 250 kW, or 5 × 70 kW to 350 kW), versus a 250 kW entry point for the EXL S1 — both at unity power factor.
- Scales in-cabinet. Upgrade 280 kW to 350 kW, or to 280 kW N+1 redundancy, by adding a 70 kW module with no added footprint. The EXL S1 requires an entire additional UPS and tie cabinet.
- No-downtime module service. Power modules are hot-swappable; the EXL S1 does not offer hot-swappable modules.
- Higher altitude without derating. Full capacity to 5,200 ft, where the EXL S1 derates above 3,300 ft.
- 40% smaller footprint, higher density. 9.2 sq ft versus 12.8 sq ft (about 20″ narrower), at up to 38 kW/sq ft versus up to 31.2 kW/sq ft.
- Longer standard coverage. 2-year on-site parts & labor warranty with factory start-up, versus 1 year.
Specification summary
| Parameter | Xtreme Power X90-5S | Vertiv Liebert EXL S1 |
|---|---|---|
| Capacity range | 50–350 kW | 250–400 kW |
| Topology | Online double conversion | Online double conversion |
| Input / output voltage | 480 V three-phase | 480 V three-phase |
| Output power factor | Unity (1.0 PF) | Unity (1.0 PF) |
| Power-module service | Hot-swappable (no system power-down) | Not hot-swappable |
| Capacity upgrade | In-cabinet via 70 kW modules (to 350 kW or N+1) | Additional UPS + tie cabinet required |
| Altitude (full capacity) | 5,200 ft | 3,300 ft (derates above) |
| Footprint | 9.2 sq ft (31.5 × 42 × 79 in) | 12.8 sq ft (51.3 × 36 × 79.1 in) |
| Power density | Up to 38 kW/sq ft | Up to 31.2 kW/sq ft |
| Warranty (standard) | 2 years on-site + factory start-up | 1 year on-site + factory start-up |
Detailed electrical specifications vary by configuration.
Where planners evaluate the X90-5S
Infrastructure planners frequently evaluate the X90-5S where:
- Lower-entry deployments needing pay-as-you-grow scaling from 50 kW rather than a 250 kW entry point
- High-altitude sites (above 3,300 ft) requiring full capacity without derating
- Footprint- and density-constrained electrical rooms
- Deployments that cannot transfer the load to utility power for module expansion or service
- Projects standardizing on a longer parts & labor warranty with factory start-up
Compare the X90-5S with other modular UPS platforms
Engineering planning support
Xtreme Power Conversion supports facility engineers, consultants, and system integrators with modular UPS architecture evaluation, electrical-room deployment planning, capacity scaling strategy, and infrastructure upgrade assessment.