Review on 🔌 Reliable and Versatile Liebert PSI5 UPS - 1500VA 1350W 120V 1U: Rack Mount Line Interactive AVR Sine Wave UPS with Surge Protection and 0.9 Power Factor by Paul Ziegler

The unit appeared to be well assembled, but when I first plugged it into the mains it emitted a horrible squeak. I think it was the fan bearings. The noise went away, but I couldn't make sure the fan was working properly. I tested it with 80% load, which caused the internal temperature to rise to 42 degrees Celsius and the fan never turned on. I emailed Vertiv and they never replied (1 week has passed at the time of writing). Sent back to Revain for a refund.