SUA1500 buzzing

Anonymous user · ‎2021-06-28

So I purchased a Smart-UPS 1500 and a few hours of being in service it started making a fairly loud buzzing sound... even turning off the load it continues to make the buzzing and only stops if I unplug the UPS... I have checked the battery terminals and everything seems fine... sometimes it will go away for a few hours and come back... its really driving me mad since my PC is nearly silent and my old Smart-UPS 1400 never made a sound when it wasn't on battery...

any ideas?

thanks

Anonymous user · ‎2021-06-28

well power definately wasnt the issue, everything was within acceptable limits... so i had the unit exchanged from the place i purchased it from and the new unit is dead silent after the fan turned off when the batteries topped off...

See Answer In Context

Anonymous user · ‎2021-06-28

No definately not a fan, sounds like a 60hz hum... could be the transformer hum I guess, but it does it even when there is load or no load...

It's at my home and i guess its usually ~75~76F...

Also the noise changes from a loud hum to a much quieter different electrical noise when the house central A/C kicks in... I've tried measuring whatever I can with my fluke 73 (frequency/voltage etc) seems normal... I have some friends that work for the power company and I am trying to get some power quality dataloggers to see if its something electrical related...

but ive never had any electrical related problems besides this one SUA1500.... ive got a newer style rackmount smartups 1500 on my hometheatre that is dead silent, along with my ancient smartups 1400 and various other UPS' around the house...

Erasmus_apc · ‎2021-06-28

Well, SUA unit fans are on low during normal online operation, and on high, when the battery has to kick in or the temperature goes up or there is a very high load on the unit. So what you describe does not sound like a fan.

I would call into tech. support and have them replace the unit, if you don't find any electrical issues in regards to the unit input.

Erasmus_apc · ‎2021-06-28

Would you describe this sound as an electrical-type buzzing (like from a transformer) or the whir of a fan? What is the temperature of the room you are operating the unit in?

Anonymous user · ‎2021-06-28

well power definately wasnt the issue, everything was within acceptable limits... so i had the unit exchanged from the place i purchased it from and the new unit is dead silent after the fan turned off when the batteries topped off...