Eaton 9SX1000IR online UPS 1000 VA / 900 W, rack 2U, 7 outlets

A double-conversion UPS continuously converts incoming AC to DC and then back to AC. The connected devices therefore always receive stable voltage produced by the UPS, not raw power straight from the grid. When the mains fails there is no transfer time, because the inverter is running all the time anyway. This is the main difference between an online UPS and line-interactive models, and the reason they are used with servers and sensitive equipment.

Apparent power is 1000 VA and real power is 900 W, giving a power factor of 0.9, so most of the nominal rating actually reaches your equipment. Size by watts: the combined draw of servers, storage and network devices must stay under 900 W, and with headroom the UPS runs cooler and the battery lasts longer during an outage. According to the manufacturer, the maximum input current is 10 A.

The UPS operates on an input voltage of 190–276 V and a frequency of 40–70 Hz, with a 50/60 Hz output frequency. The wide frequency window matters most when the UPS is fed from a generator whose frequency drifts as the load changes. In online mode the UPS evens out these swings before they reach the server, so the connected equipment receives clean power even when the building supply is restless.

The chassis measures 438 × 438 × 86.5 mm and occupies two rack units. At 15.7 kg it is best mounted low in the cabinet on sturdy rails or a shelf. The LCD display on the front panel shows the UPS status right at the rack. The colour is black. The manufacturer quotes a noise level of 41 dB and an operating temperature of 0–40 °C, which suits an ordinary cooled server room.

Management is handled through one USB 2.0 port and an RS-232 serial interface. Through them the connected server learns when the UPS switches to battery, and power management software shuts the system down cleanly before the battery is drained. That prevents file system errors and half-written database records. The UPS meets the IEC/EN 62040-1, UL 1778 and CSA 22.2 safety standards and IEC/EN 62040-2 and FCC Class B for electromagnetic compatibility.

Server rooms and racks where a database or file server must not feel a single interruption; businesses with an unsteady power supply or a backup generator; and IT administrators who need a compact 2U unit with seven outlets for loads up to 900 W and prefer online topology over a line-interactive model.