Can you hear a hum coming from your UPS?

[coolpurplefan]

I can hear a slight hum coming from my Tripp-Lite Omni VS 1500 if nothing in my appartment is making noise (like refrigerator and the windows are closed).

Does anyone else hear a hum from their UPS? If so, what is the brand name? Or, actually, what is the brand name if you cannot hear a hum?

 

[SparkyJJO]

My APC BackUPS ES 725 hums, and when the battery kicks in it buzzes some and makes my PSU in my PC buzz a little as well (since it doesn't make a perfect sine wave output, this is normal). It is the charging transformer and circuitry that you are hearing.

 

[coolpurplefan]

Originally posted by: SparkyJJO
My APC BackUPS ES 725 hums, and when the battery kicks in it buzzes some and makes my PSU in my PC buzz a little as well (since it doesn't make a perfect sine wave output, this is normal). It is the charging transformer and circuitry that you are hearing.

Do you have a lot of power outages in your area? Has a power outage ever damaged RAM? (It happened to me.)

 

[SparkyJJO]

Originally posted by: coolpurplefan

Originally posted by: SparkyJJO
My APC BackUPS ES 725 hums, and when the battery kicks in it buzzes some and makes my PSU in my PC buzz a little as well (since it doesn't make a perfect sine wave output, this is normal). It is the charging transformer and circuitry that you are hearing.

Do you have a lot of power outages in your area? Has a power outage ever damaged RAM? (It happened to me.)

Depends on the time of year During the spring/early summer there tend to be more of them (this year has been good so far though). Main reason why I got it though was I got it brand new from ebay for $28 shipped $90 unit at the time too Poorly written auction ending at a weird time, but I knew what I wanted hehe.

Power outages don't usually damage hardware if the power just shuts off. If it flickers, brownouts, or pulses before shutting off completely that can damage stuff. Even a good surge protector can't protect against the low voltage pulsing/flickering that can happen with a brownout. A UPS does because of the battery backup.

 

[Modelworks]

I have an apc smart ups 1000 that hums.
Actually if your in the room and its completely quiet you can hear the ups making a humming noise, then go silent, humming, silent. Alternates about every 20 secs.

I traced it down to the ups checking and charging the batteries.
I placed a voltmeter on the battery leads and it goes up about .5 volt when I hear the humming sound.

I have about 600amps worth of batteries attached to it, I like loooong run times
It did the humming thing before I attached the extra batteries so its not related.