E91 30 kVA vs Eaton 9355
The Xtreme Power E91 30 kVA and the Eaton 9355 30 kVA are online double-conversion UPS systems for 208/120V three-phase applications. The E91 delivers full 30 kW output at unity power factor with higher efficiency and dramatically lower system weight; the Eaton 9355 provides longer base runtime but at reduced usable output (27 kW) and more than double the system weight.
Where the E91 30 kVA leads
- Full 30 kVA / 30 kW usable output at unity power factor — vs the Eaton’s 27 kW.
- Higher operating efficiency (94% vs 91% online).
- Dramatically lower system weight (496 vs 1,160 lb) and floor loading.
- Runtime specified at full rated load, with factory start-up and a longer standard electronics warranty.
30 kVA three-phase UPS, side by side
| Specification | Xtreme Power E91 30 kVA | Eaton 9355 30 kVA | Advantage |
|---|---|---|---|
| Rated capacity | 30 kVA / 30 kW | 30 kVA / 27 kW | Full real-power output, unity PF |
| Output power factor | 1.0 | 0.9 | More usable kW from same kVA |
| UPS topology | Online double-conversion | Online double-conversion | Comparable protection |
| Efficiency (online) | 94% | 91% | Lower energy and cooling demand |
| Maintenance bypass | Standard (integrated) | Standard (integrated) | Both integrated |
| Dimensions (W × D × H) | 23.6 × 36.3 × 65.6 in | 20 × 34.1 × 66 in | Comparable size; E91 lighter & full kW |
| Weight (with batteries) | 496 lb | 1,160 lb | Dramatically lower floor loading |
| Internal runtime | 6 min std / 9 min ext @ 30 kW | 11 min @ 27 kW | Eaton longer, but at 27 kW & far heavier |
| Runtime expansion | External battery cabinets | External battery cabinets | Comparable scalability |
| Warranty (electronics) | 2 years | 1-year parts | Longer standard coverage |
| Start-up & labor | Factory start-up included | Start-up optional; 90-day labor | Lower deployment cost |
| TAA compliance | TAA compliant | TAA compliant | Eligible for federal procurement |
Both are true online double-conversion three-phase UPS with integrated bypass and TAA eligibility. The E91 delivers full 30 kW usable output (vs 27 kW), higher efficiency, and dramatically lower weight (496 vs 1,160 lb), with factory start-up and a longer warranty. The Eaton provides longer base runtime, but at reduced output and more than double the weight. Confirm Eaton 9355 specifications against current Eaton documentation.
Choosing between them
Choose the E91 for full 30 kW usable output, far lower floor loading, higher efficiency, factory start-up, and longer warranty; the 9355 fits where longer base-cabinet runtime is the priority and higher system weight is acceptable.
Choose the E91 30 kVA if you need
- Full 30 kW usable capacity
- A significantly lighter UPS system
- Higher operating efficiency
- Runtime specified at full load
- Factory start-up included
- Longer standard electronics warranty
The 9355 30 kVA may fit if you need
- Facilities standardized on Eaton infrastructure
- Longer base internal runtime is the priority
- Higher system weight is acceptable
Related comparisons
Standardizing compact three-phase UPS across your facilities?
Xtreme Power supports E91 three-phase UPS sizing, runtime planning with external battery cabinets, modernization strategy for legacy three-phase UPS, and TAA-compliant procurement for healthcare, education, retail, industrial, and enterprise infrastructure.