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Internals of APC Smart UPS and fan noise

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Last response: in Components
May 12, 2009 3:00:34 PM


I recently purchased a SUA 1000xl smart ups from APC. I love the product except for one small problem. The fan is ALWAYS running on low. I can unplug the unit from the wall and the fan is still running.

I'm thinking about replacing the fan with a quieter fan. Does anyone have pictures of the internals of a Smart UPS that I can look at before I start the surgery?


More about : internals apc smart ups fan noise

a c 114 ) Power supply
May 12, 2009 4:49:49 PM

You should contact APC to get that info.
October 12, 2010 10:13:55 AM

I also bought the SUA 1000XL and its fan is always on, even with the unit switch off, and is deafening. I think this unit is only for data-centres which it doesnt tell you on the website. Its by far the loudest thing in our office, louder than all our servers, UPS and pcs put together. Its rated at 42dB, which is louder than our air conditioning unit (which is rated at 22dB).

So if you find a solution to this jet engined machine, let me know.

February 20, 2011 4:32:16 PM

I also have a SmartUPS that has a very noisy fan and sometimes seems to vibrate/resonate. Mine's a model SMT1000, not a SUA model. The fan in this unit is made by ADDA and has the following specs: 80x80x25 mm, 24V (**yes, 24V**), 0.10 A, 2440 RPM, 31.4 CFM, 28.3 dB(A). I measured the noise as 45 dBSPL (1 ft to the side of the unit) when it was "vibrating" and 42.8 dBSPL running "normally".

I had hoped to reduce the noise by replacing the sleeved fan with a higher quality one but the fact that this one runs off a 24-Volt supply has made it hard to find a suitable replacement. Why APC would put such a cheap, noisy fan in such an expensive UPS is beyond me except that I guess they are targeting servers with this unit. I would not recommend anyone purchase the SMT1000 for use in any room where someone also worked or relaxed.