I bought a UPS a year back to use in the server rack.
What I did not think of was the noise level. I think I saw the specs and saw a fan, but didn’t think it would be spinning all the time, or to be so loud.
Well, I was wrong and the fan was a bit louder than I could accept.
First thing I tried was the easy one. I just swapped out the fan with another one I had, a Noctua. Known for their silence.
That worked for 5 minutes, after which the UPS decided the fan had stopped and turned itself off. The fan WAS running, though.
Apparently there must be an incompatibility with the RPM-sensors – perhaps.
Another solution was needed..
So I ordered a fan speed controller from eBay, and hoped it could be used with the original fan.
This is the UPS I have. It is an PowerWalker VI 1500 RT.
So it’s an 80mm fan placed underneath the black shroud. It’s connected to the motherboard via a three-wire plug, which btw is not the same as you would use in a computer. So you need to reuse the original connector.
So, I took my Zalman Speed Mate 2 and cut off its connectors. Then I matched the colours on the fan and the fan mate’s wiring – black -> black. Red -> red. White -> yellow. Soldered them together.
Started it up, and adjusted the fan speed to an acceptable noiselevel – and let it run for 30 minutes to see if it would shut down again like last time. It did not! Success!
So I tucked the wiring away and placed the controller on the inside – hopefully no more use for it.