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Old 07-29-2012, 09:52 AM   #8
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Join Date: Jul 2007
City & State: East Coast, USA
Line Voltage: 220-221
I'm a: Professional Tech
Posts: 4,145
Smile Re: Need tips in fixing APC 1500VA UPS having buzzing noise

Please attach pics to posts. Links to external site disappear or become broken, and the info provided by you is lost.

That being said, Epcos B32232 sheet attached. Metallized Polyester Film.

SUA1000VA is not a 1500VA UPS...? 1000va = ~670 watts / 1500va = ~980 watts

Noise may very well be from another component. Usually, by time these caps start buzzing, it's too late. I've never seen one fail. The orange drop caps nearby (also MPF) I see fail when high spikes on the line occur. Telltale is a change in color or a crack/burn in the casing.

Yes, it's used for "smoothing" the output when in "running" mode.

Be nice to see a pic of the whole area. I'm assuming the pic in #3 is your unit.

Could also be noise from another device on the line this is connected to. Cheapo Chinese fluorescent ballasts radiate that and can be feeding it onto the line. Try moving it to another circuit.

You have enough "noisemakers" nearby to probably discount these as failures. I see 6 relays and several coils/chokes nearby. That entire bank of rectifiers/FETs can also be noisy at times.

DigiKey & Mouser carry some of this Epcos line, but not enough. $20 sounds about right going by their other caps in the line. That is a big mother.


PS: Make sure any output side power strips are -NOT- surge protected. They -say- sine wave, but spikes do occur and will quickly take out the MOVs, especially if lightly loaded.

Attached Files
File Type: pdf MKT_B32232.pdf (287.9 KB, 17 views)
veritas odium parit

Last edited by Toasty; 07-29-2012 at 10:03 AM..
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