Eaton 5PX G2 5PX3000IRT2UG2 UPS 3000 VA / 3000 W, RT2U, line-interactive

Many UPS units offer fewer watts than volt-amperes because their power factor is 0.6 to 0.9. Here both figures are 3000, so connected devices may draw up to 3000 W in total. That covers several servers together with a storage system and network switches. Leaving some headroom still extends battery runtime and keeps the UPS cooler.

A line-interactive UPS corrects minor mains voltage fluctuations without drawing on the battery and only switches to battery when power fails or the voltage leaves the permitted range. The batteries are not worn down by every small disturbance, and server room equipment receives more even power than it would straight from the grid.

The RT2U in the model name marks the Eaton rack/tower version with a height of 2U, or two rack units. The UPS therefore fits a 19-inch server rack but can also stand upright on the floor. The manufacturer data does not say whether rails or a mounting kit are included, so check that before installation.

According to the manufacturer the UPS weighs 31.7 kg, most of it in the batteries. In a server rack, mount it as low as possible to keep the centre of gravity down, and lift it with two people. Leave enough space in front of and behind the unit for airflow.

Company server rooms where several servers and a storage system need time to shut down cleanly during an outage; IT administrators building a 19-inch network rack who want the UPS to take up only 2U; and offices where the network, phone system and point-of-sale system must not stop because of a power failure.