UPS making noise?

[malm11]

I'm getting conflicting answers -

I bought an apc smc1500 to protect my pc components.

But when I plugged my new APC, it makes a fairly loud buzzing noise when it's *not* under battery load and *not* connected to anything aside from being plugged in.

I can't find a solid answer online. To me, the constant buzzing doesn't seem normal.

What are your experiences with UPS devices?

 

[GhislainG]

Once the batteries are fully charged and there's no power outage, then it should be very quiet. If you disconnect it from the outlet, then it will be noisier.

 

[malm11]

Yes, when I disconnect it and it runs on the battery, it makes a fan running noise which sounds normal to me.

But when the battery is fully charged and there's zero load, the unit makes a constant buzzing noise.

 

[GhislainG]

My Smart-UPS 1500 doesn't make a loud buzzing noise. My Smart-UPS 1000 which is closer to my desk also is quiet.