SMT1500I intermittent loud buzzing

[Anonymous user]

Hello,

My SMT1500I that I bought about a month ago sometimes starts buzzing pretty loud as well as vibrates while it's buzzing. Usually it lasts for a few minutes and then goes back to normal. I checked and during buzzing it's not in AVR mode and it's not on battery. My guess is transformer is causing that. Is this normal behaviour for my UPS?

Thanks.

[BillP]

Hello,

How much and what type of load is on the UPS? How often is intermittent? It could also be because the UPS is charging - not sure if you noticed that was the case or not. I think some noise is normal for Smart-UPS - it could be vibration or some dull fan noise. It could also be because of whatever type of load/power supply is connected to the UPS output. I am not sure, depending on how intermittent it is, if you can see if you see the same behavior with no load.

In general, I would probably guess that it is normal but the questions above may help confirm or deny that.

[Anonymous user · Accepted solution]

Buzzing happens very rarely, once every 2 days, I think. And it goes away in a few minutes. I don't particularly mind it, as long as it's a part of normal UPS operation. My UPS loads are really low, 10-20% usually, I maxed out at 45% a couple of times, and at night I shut computer off so it's 0% load.