When you're shopping for UPS critical power, the first fork in the road is usually used versus new. The Libert Vertiv PSI5-1500RT120 is a used 1500VA/1350W rackmount/tower unit at $149.99, while the Eaton 5P 1U is a new 1550VA/1100W rackmount UPS at $289.99. One brings more watt capacity for less money; the other brings new-in-box status, 1U density, and six C13 outlets. Here's how to pick.
Quick verdict
If your gear runs on standard 100-125VAC and you want the highest continuous wattage for the lower price, choose the Libert Vertiv PSI5-1500RT120. If your rack is on 208/240V and new condition matters more than price, the Eaton 5P 1U is the better fit.
Comparison
| Feature | Libert Vertiv PSI5-1500RT120 | Eaton 5P 1U 1550VA |
|---|---|---|
| Price | $149.99 | $289.99 |
| Condition | Used | New |
| VA / Watt rating | 1500VA / 1350W | 1550VA / 1100W |
| Input voltage | 100-125 VAC | 208/240 V (200-240 V) |
| Form factor | Rackmount/Tower | 1U rackmount |
The Eaton's higher price buys new-condition hardware, a 1U rack height, and wide 200-240V input tolerance. The Vertiv's lower price buys a higher 1350W output, but with used condition and a 120V input requirement.
Where each product wins
Pick the Libert Vertiv for a 120V rack where the lower price and higher watt capacity outweigh the used condition. Pick the Eaton for a 208/240V rack where new condition and 1U density matter more than the price difference.
Product notes
#### Libert Vertiv PSI5-1500RT120
The more affordable Vertiv carries the higher continuous watt rating in this comparison at 1350W. This unit has been pulled from a working environment and individually tested: it powers on, the LCD works, it passes its built-in self-test, batteries charge normally, and no replace-battery warnings appeared. For a used UPS, that's a useful level of transparency. The pure sine wave output and automatic voltage regulation make it a good fit for sensitive gear, while the rackmount/tower form factor gives placement flexibility. The limitation is that this unit is made for 100-125VAC circuits, so it won't work in a 208/240V rack. Used condition also means you're not getting factory-fresh assurance. For a 120V setup, this is the one to choose.
#### Eaton 5P 1U 1550VA
The Eaton is the new-in-box choice, and that alone can justify its higher price when uptime matters. It's a 1U rackmount UPS rated at 1550VA/1100W, with six C13 outlets and support for 200-240V input. High-efficiency mode delivers greater than 95% efficiency, which is meaningful for always-on equipment. The trade-offs are the roughly $140 price gap and lower watt capacity compared with the Vertiv. This unit is also built for higher-voltage racks, so it won't run on a standard 120V outlet. If your rack already runs on 208/240V and you want a new, compact UPS with more outlets per rack unit, the Eaton is the stronger fit.
Final choice by use case
- For a 120V home lab or small rack where lower price matters: choose the Libert Vertiv PSI5-1500RT120 for its 1350W, pure sine wave, and AVR.
- For a 208/240V server rack where new condition, 1U height, and six outlets matter: choose the Eaton 5P 1U 1550VA.
