I have an Uninterruptable Power Source, an Eaton 5115 Model Number: MDL-PW5115 750i USB which I bought in Austria in 2008. It has been running fine, with no alarms, giving me 240 volts for Austria and Germany, protecting a MacPro and a Raid Array for Video Editing. But I have had to replace the original fan, a Chinese Yate Loon fan. 60mm wide. The closest fan I could find that matched the original fan was a Noctua NF-A6x25 FLX which has a rotational speed of 3000 with no adaptation. Which is the way I installed it into the 5115. It has adaptors that can take it down to 2400 and 1600 rotational speed if desired or required. But I did not use these adaptors. The maximum input power tops out at 1.44W/ 0.12A and the input is 12v. The old Yate Loon fan also runs on 3 pins for 12 v. But the only other spec is on the fan "0.18A". I installed the Noctua and it ran immediately in the 5115 for about two minutes before the 5115 kicked off an alarm indicating, according to the manual, a "fan" warning. The fan throttles up and down and stays running quietly in the normal "throttle down" but not off mode. The light for the + plus - minus symbol blinks about every 2 seconds. The top On light stays solid green. The alarm "beep" is a continuously on shrill sound. But the UPS "works", the fans hums along nicely and the warning continuous signal can not be shut until the power cord is pulled from the wall. I disconnected the yellow wire that "senses" the motor state but the alarm continues when plugged back in. The difference I see in the fan I ordered and the old worn out fan is the 0.12A max input for the new Noctua fan, and the 0.18A for the old fan. Has anyone heard of a Mod inside the UPS that can make the new fan acceptable to the 5115 UPS? Such as turning a potentiometer on the board components to change the voltage in the fan circuit or changing the Alarm relay that doesn't like my new more efficient fan? Or perhaps of a specific firmware update to the Eaton 5115 UPS that allows the user to adjust settings for a new fan? Eaton themselves, given all the serial and model numbers from the 5115 could not tell me the fan that was in this unit. So, I don't expect them to be able to tell me how to adapt it to the newer 60mm 12 volt 3-pin fans on the market in 2013. I would appreciate any useful suggestions! Thank you.