APC Smart 1500 SC - buzzing whilst on battery - normal?

[Anonymous user]

Hi

I just wanted to ask, is it normal for the Smart 1500 SC to buzz when on battery? It's quiet otherwise. More importantly, I noticed the server power-supply also emits a similar buzzing when the ups is on battery (this too is quiet when on mains power). I was concerned I might be dramatically reducing the life of the server power-supply somehow?

The buzzing itself is fairly loud, not very, but enough to make me wonder if i've just purchased a faulty unit.

There's only the one server on the Smart 1500, it's an HP ProLiant ML110 G4.

Thank you

Steve

[Anonymous user]

SteveB wrote:
Hi

I just wanted to ask, is it normal for the Smart 1500 SC to buzz when on battery? It's quiet otherwise. More importantly, I noticed the server power-supply also emits a similar buzzing when the ups is on battery (this too is quiet when on mains power). I was concerned I might be dramatically reducing the life of the server power-supply somehow?

The buzzing itself is fairly loud, not very, but enough to make me wonder if i've just purchased a faulty unit.

There's only the one server on the Smart 1500, it's an HP ProLiant ML110 G4.

Thank you

Steve

Buzzing from the UPS itself is normal. Modified square-wave type UPS will make buzzing sound and cause the PSU to emit a similar sound.

Sinewave UPS tend to hum rather than buzz and it does not make the PSU make any unusual noise.

The SC line of Smart-UPS is the economy version that puts out a modified squarewave, like the red graph. Modified sinewave would look more like sinewave simulated in multiple steps in ascending and descending, but marketing literature would usually call modified squarewave as "modified sinewave"

The noise is caused by sudden rise and fall in voltage in waveform. For the duration your PSU operates on it, it shouldn't affect service life.

http://img142.imageshack.us/img142/2597/waveforms600hi3.jpg

[Anonymous user]

"For the duration your PSU operates on it, it shouldn't affect service life."

Where I live there can be power-cuts every day. Sometimes they last for 5 minutes, other times they can last for hours.

With just the one server on the Smart 1500, it can stay running on battery for 60+ minutes...the PowerChute software has 2 options for auto-shutdown - on "battery limit" or "60 minutes" (max allowable value in the box). I currently have it set to shutdown after 45 minutes on battery.

You use the words "shouldn't affect"...would I be better off having the server auto-shutdown after...15 minutes? Is the buzzing going to shorten the life of the server PSU if it did it every day ?

Thanks

Steve.

Message was edited by: SteveB

Message was edited by: SteveB

[TheNotoriousKMP_apc]

Hello,

What is the power capacity (in Watts) of the server? Is the software reporting that you have 60 minutes of runtime available? That figure seems a little high, as you would normally see 45 minutes tops with approximately a 400W server, if not less. Again, the buzzing is most likely in response to the step-approximated sine wave, and may or may not be damaging to the PSU on the server. You should contact your server manufacturer for more details on how that can affect the overall performance and life expectancy of the server.

[Anonymous user]

Hi

Looking at the PSU in the server, it's rated at 300W for 12V and 130W for 3.3V (it's what came with the ML110 G4 when it was bought).

The PowerChute software reports load to be at 7% with 119 minutes of Runtime Remaining. This figure usually drops quite quickly (at least initially before stabilising at a slower decay) when the mains power does actually fail, but I am confident it'll do at least 60 minutes before the battery is exhausted.

If having the server on battery for prolonged periods (> 10 minutes at a time) is infact "damaging", then it seems i've invested in a $500 UPS that actually shortens the life of my server 😞

Steve

[Anonymous user · Accepted solution]

SteveB wrote:
"For the duration your PSU operates on it, it shouldn't affect service life."

Where I live there can be power-cuts every day. Sometimes they last for 5 minutes, other times they can last for hours.

With just the one server on the Smart 1500, it can stay running on battery for 60+ minutes...the PowerChute software has 2 options for auto-shutdown - on "battery limit" or "60 minutes" (max allowable value in the box). I currently have it set to shutdown after 45 minutes on battery.

You use the words "shouldn't affect"...would I be better off having the server auto-shutdown after...15 minutes? Is the buzzing going to shorten the life of the server PSU if it did it every day ?

Thanks

Steve.

I meant that it's not running on modified squarewave 24/7/365. Couple hours a week should not pose a problem. Since you have frequent outages, I would at least quadruple the runtime reserve. So, if you frequently have 30 minutes outages, get something that gives you 2 hours of runtime. Your battery will not last long at all if it's allowed to discharge deeply frequently.

Message was edited by: KVAr

[Anonymous user]

@KVAr - ok, that's useful to know, i've adjusted the PowerChute "automatically shutdown server after X minutes on battery" to 30. This should keep the server PSU happy and the battery in reasonable condition for as long as possible.

Thanks to both of you for your time, much appreciated 🙂

Steve.

[Anonymous user]

@KVAr - ok, that's useful to know, i've adjusted the PowerChute "automatically shutdown server after X minutes on battery" to 30. This should keep the server PSU happy and the battery in reasonable condition for as long as possible.

Thanks to both of you for your time, much appreciated 🙂

Steve.

[Anonymous user]

SteveB wrote:
@KVAr - ok, that's useful to know, i've adjusted the PowerChute "automatically shutdown server after X minutes on battery" to 30. This should keep the server PSU happy and the battery in reasonable condition for as long as possible.

Thanks to both of you for your time, much appreciated 🙂

Steve.

To clarify, I gave 30 minutes as being 25% of 2 hours. If you have very frequent long outages, set it for about 25% of maximum runtime. If you can only get an hour, then set it for 15 minutes. If this doesn't work out, you may want to get something like a SU1000XL refurb or a brand new SUA1000XL.

[Anonymous user]

Hi

I just wanted to ask, is it normal for the Smart 1500 SC to buzz when on battery? It's quiet otherwise. More importantly, I noticed the server power-supply also emits a similar buzzing when the ups is on battery (this too is quiet when on mains power). I was concerned I might be dramatically reducing the life of the server power-supply somehow?

The buzzing itself is fairly loud, not very, but enough to make me wonder if i've just purchased a faulty unit.

There's only the one server on the Smart 1500, it's an HP ProLiant ML110 G4.

Thank you

Steve