UPS shows continuous coil whine even when idle and the fan remains on, is this typical or a fault?
UPS shows continuous coil whine even when idle and the fan remains on, is this typical or a fault?
Hi everyone,
I recently purchased a brand new Eaton 5P1550iG2 UPS (tower model) and am trying to determine if the noise it produces is typical or if there’s an issue with the device.
Here’s what I’ve observed:
When unplugged, the battery was around 90%. After plugging it in, it took nearly two days to fully charge. On the first day, only the standard fan noise was audible. The next day, a steady high-pitched coil whine or buzzing started. Using a phone app, I measured the sound level and it exceeded 40 dB even when the unit wasn’t running any load.
Currently, the UPS hasn’t powered any devices—just been charging. The fan operates continuously, never stopping, even in a cool environment.
Based on what I understand about the Eaton 5P series, they should generally be quiet (around 30–35 dB) and shouldn’t generate coil whine, particularly when idle.
My concerns are:
- Is coil whine typical for this model?
- Does the fan run 24/7 on these units?
- Could this sound indicate a faulty inverter or inductor, or something else entirely?
- Should I consider returning it?
Thank you!
Hi, thank you for your message.
Currently, there is no load connected to the UPS — I only connected it to charge.
The coil whine occurs even when the UPS is completely unloaded.
I made a short video capturing the noise for reference.
It was recorded during the middle of the night, so the surroundings were very quiet.
Please review and let me know if this sounds typical or suggests a problem.
Ups noise
Upload your video to another location and share the public URL here. Asking if exchanging the UPS is possible.
Yes, it's possible to return or exchange the UPS because I only bought it two days ago. However, since I'm in Iceland and the UPS was purchased from Germany through eBay, the return shipping costs would be very high. I want to confirm this issue is genuine before deciding to send it back. Please check the video here:
View: https://youtube.com/shorts/x_7NgDHx6qI?s...8fdtZ-LjfX
Link the PC to the UPS to observe if a load alters the operation. That is quite noticeable.
I linked the UPS to my NAS and positioned it in the corner of the room, just like the video shows. The space is bigger now, which makes the noise less obvious. The coil whine is softer than before, but you can still hear a high-pitched “eee” sound from about two meters away. It’s quieter overall, though it’s still audible. The fan continues to run constantly. Would you think this is typical for this model? I’m very sensitive to noise, especially at night when I work, so this worries me. Thanks.
eBay? So you purchased a used UPS? If yes, please return it.
If you're looking for a dead silent UPS, I can recommend the CyberPower CP1300EPFCLCD (1300VA/780W, line-interactive, true/pure sine wave). I own this model for six years now. I actually have two of them, each powering one of my desktop PCs (see specs and photos in my profile).
Spoiler:
Picture of my UPSes (click here to view)
In fact, the entire CyberPower PFC Sinewave series is dead silent.
Revision 1 lineup:
https://www.cyberpower.com/eu/en/product...._1#models
Revision 2 lineup:
https://www.cyberpower.com/eu/en/product...._2#models
And these UPSes are easily found on amazon.de
Yes, you're completely right. Bringing it back would be very expensive due to shipping costs, and I also asked my wife about the sound — she said it doesn’t bother her at all, so I’m trying to adapt to it myself.
Excluding the noise issue, the device looks strong in terms of power quality and components, which means I’ll likely keep it.
I’m considering adding some pyramid acoustic foam on the wall behind the UPS and possibly under the desk above it. It could help reduce the noise even more.
Thanks a lot for your assistance! Have a great day!