Electric arc noise

[axelrvf]

Hello everyone,

I own a apc Back-UPS RS 1200G. I bought it about 15 days ago. I have a problem with the unit.

When power is cut and my computer turns to battery, a very distinct electric arc noise is heard from inside the ups.

I contacted Schneider/APC here in Greece (phone number is 211990610) and the technician in charge told me that it is totaly ok to hear such a sound coming from the ups. Is that true? To my understanding (i am an electronics engineer). This means potential hazard and risk of fire.

Am i right? Is there a way (a email) to contact apc formally so that they will verify what the local schneider/apc technician told me? Otherwise i would like to file a formal complaint.   

Best Regards

[Teken]

Make a video show casing this problem in action and offer a direct link so it can be  reviewed.

[axelrvf]

Here you go

https://vimeo.com/904701305?share=copy

[Teken]

Based on the provided video the sound is indeed coming from the transformer (inverter system). All UPS make some kind of sound when they use their inverter to convert DC to AC. That sound can vary in pitch, tone, and volume. Larger UPS systems also have an internal fan which adds to perceived noise level. 🙁

I did not hear any kind of arcing (sounds) based on the short video. If you feel the noise is too loud it’s up to you to return / RMA the unit. You have a 50/50 chance of receiving one that is quieter but you could receive one that is the same or even louder! 🤦‍♂️

Appreciate you taking the time to make the video. Let us know what you decide to do and the final outcome. 👍

[axelrvf]

The noise - not sound, my bad - as you noticed, comes from inside the ups. This is by no means a normal noise. Maybe a production line flaw that Schneider/Apc refuses to accpet. You know that, over a period of time, this may result in, two contacts overheating, overheating means fire.

  If you have ever welded with a mig or a tig welder, you can understand what i mean by arc noise. At another post in this forum, that someone had the same issue, the answer he received is that no sounds or noise should be coming from inside the ups.

Can Schneider/Apc give me  a formal answer to this issue? Should i or should i not be hearing ANY noise at all coming from the inside of the ups?

I have already sent back one ups for this reason. The contact person for schneider/ups here in greece, after i sent a video showcasing the noise, said that there is no problem with the new ups.

This is why i am asking for a formal answer from Schneider/Apc. I just want a formal written verification regarding this problem.

Here is another clear video clearer than the first one.

https://vimeo.com/manage/videos/905595335/privacy

Thank you for taking the time to answer my question

[Teken]

At seven seconds into the video is that loud snap sound from when you unplugged the UPS? 🤔 As the video plays on it’s clear the other noise is from the inverter circuit which typically sounds like buzzing / humming.

That is atypical for these sort of devices built to a price point. Regardless, the perceived sound level is made a lot worse given the unit is sitting between a wall and cabinet which acts like a speaker with little room on either side. Having two reflective surfaces in what (audiophiles) call a bright room would be hard to ignore.

Id be interested to see & hear the the UPS out in the middle of the room. Have the phone held in place with a tripod next to the UPS. Then disconnect the power cord so we can hear exactly what happens when AC Mains is removed. It’s too hard to tell if the other sounds are coming from you simply moving around and banging things as you disconnect the AC Mains.

This APC FAQ speaks to the noise produced by an Enterprise Symmetra UPS. But this information also applies to the consumer level UPS systems: https://www.apc.com/ca/en/faqs/FA157596/