Vertiv's published efficiency for the Liebert EXL S1 in double-conversion (VFI) and ECO (VFD) modes
up to 97% VFI vs >99% ECO/VFDobserved
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| Scope | Vertiv's ratings for the Liebert EXL S1 625-1200 kVA; efficiency changes with loading. Vertiv rates Dynamic Online (VI with VFI support) separately at up to 99%; it relies on instantaneous inverter takeover rather than a transfer. Loss as a share of input is 1 minus the efficiency; as a share of output it is 1/efficiency minus 1, or 3.09% at 97%. Checked against the datasheet on 2026-10-13. |
| As of | 2020-01 |
| Source | Vertiv Liebert EXL S1 UPS datasheet SL-26095 (R01/20) · Page 2, Typical Functioning Modes: double-conversion (VFI) efficiency up to 97%, ECO-mode (VFD) efficiency above 99%, Dynamic Online (VI) up to 99% |
| Review | checking…review by 2027-10-01 · standard cadence |
| Recorded changes | last 2026-10-13 · 4 revisions tracked |
| Claim id | double-conversion-loss-vs-eco-mode-advanced |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.