Transformerless
The transformerless range groups all Riello UPS systems built without an output transformer. The technology — see High-Frequency Topology and FAQ - Transformerless UPS — uses high-frequency switching to regulate output via a small filter inductor instead of a 50/60 Hz output transformer. The result: smaller footprint, higher efficiency, and lower capital cost per kVA. The trade-off is loss of Galvanic Isolation and reduced robustness under harsh inverter loads.
Most of the Riello single-phase line and the lower-end three-phase line falls into this category — the Pure Line family is explicitly transformerless high-frequency, and the Sentinel Pro / Sentinel Dual SDU / Sentinel Tower / Sentryum online double-conversion units are also transformerless designs.
Members
- Pure Line — high-frequency, 1–10 kVA tower
- Pure Line Rack — rack-mount Pure Line variants
- Pure Line Tower 6-10kVA — higher-power industrial Pure Line tower variant
- Sentinel Pro — 700–3000 VA online double-conversion tower
- Sentinel Dual SDU — 4–10 kVA rack/tower convertible
- Sentinel Tower — 5–10 kVA tower
- Sentryum — 10–20 kVA tower with three-phase variants
Connections
- (range members listed above)