5PX2200 UPS cooling & noise management


Limp Gawd
Apr 2, 2011
I bought a 5PX2200iRTN UPS some time ago but the two 80mm fans make some very loud noise, even when the batteries were fully charged the fans slowed down a little but the noise is still unbearable for a quiet desk environment, so it's currently unuseable and lay here till now.
I suspect the unit to be rated for sitting in a rack and then nothing has been done to make it home friendly.

Here are the fans used inside (ref:ME80251VX-0000-G99) rated at 3600RPM 46CFM

The plugs are like some graphic card mini3pin but with the RPM wire on the middle (at right, vs the common 3pin fan plug at left):

I heard that heat harm battery's life, but as you can see here the batteries are completely isolated from the air flow:

I also have a line interactive APC SMT750I you can see on the background of the last pic that is completely fanless and silent, making me think a powerful airflow isn't absolutely necessary for a line interactive UPS (unlike online UPS).

There is also the way more quieter Eaton 5P product line that don't have the powerful external EBM battery charger the 5PX line have, making me think the EBM charger is responsible of the powerful fans used in the 5PX.

The 5PX line claim high efficiency up to 99%, and i seriously doubt it really need that much cooling, because that would mean it consume a ton of power for nothing.
The only real work occur when there's some power outage and after when it need to recharge the batteries, but in normal condition when there is available clean enough power and the batteries are charged there should be very little power consumption.

So as i won't add additionnal battery modules and thereby won't make use of the EBM charger i was wondering if that would be possible to replace the two noisy fans with quieter ones, like some noctua NF-R8 for example?

I never done this and i'm not very used to mod UPS so i don't know if there are parts that really need to be actively cooled and how much i can lower the fan's RPM without harming the unit or breaking something?
How to scale the fan speed to keep sufficient cooling even during a power outage

Has anyone already done this kind of thing, or have useful knowledge about this kind of hardware?
What's your opinion about that?


Sep 6, 2015
Did you find a solution to the loud fans on this UPS? Did you try the "Cooler Master Blade Master 80" fans?


Limp Gawd
Jun 7, 2004
Sorry to ressurect an old thread... I too was wondering if the OP ever replaced the fans in this UPS. I have a similar model (5PX1000rt) and have at least one fan that's rattling and probably about to fail. (The UPS is in a somewhat dusty environment, and I have to blow the dust out of the fans regularly and have cleaned and reset a "fan error" at least once now).

I don't care so much about making the UPS quieter, but I guess my main question is whether the OP confirmed the fan wiring? Is the RPM sensor wire on the middle pin versus the "standard" (computer case fan) wiring with + on the middle pin of the fan connector? Just trying to confirm whether it's the RPM wire placement, or color, that's "unconventional" from the usual PC case fan... ;)


Apr 11, 2020
Hi guys,
I decided to change the stock fans on my EATON 5PX3000 and i ended up on this forum.
I searched for some info on internet and from the results, I was confident enough doing it.

To sum up, for this kind of UPS there should always be a small airflow, can't run fully passive, but it doesn't need that much cooling anyway.

The 5PX3000 needs 3 fans, 1 in the front, 2 in the back, i choose the Arctic F8 TC (https://www.amazon.fr/gp/product/B0037AUS4S 6.95€ with prime) , which are cheap and run at 500 RPM unless the temperature rise above 32°C, then it will accelerate (linear) to 2000RPM.
Well, the temperature sensors didn't (on the 3 fans) kick in until ~40°C, but it was acceptable.

As Mastaba said, the pins wiring and connector are not standard, plus, they are glued. So i cut the end for it and plugged it with dupont connectors in the new ones.




Here is a photo with the two rear fans already changed and connected :



To remove the front cover, remove the 2 left torx screws then slide the front panel to the right :


I put some masking tape on the connectors just to be sure :


And then I bring the 3 thermal sensors of the fans together on the central coil.
The place was the one heating (using an infrared thermometer) the most when on battery and it's on the center of the air flow right after all theses heat sinks :

The average load on my UPS is 20%, no fan errors on the UPS, temperatures are fine 25,6°C in 32,4°C out (in a closet cabinet with 2 servers, 2 switches and some other stuff, with cabinet exhaust around 35°C).
Everything seems ok.

The noise has reduced even if the average noise of my cabinet didn't change that much, still around 45dB.

Didn't cost much, good improve.

Enjoy guys =)

Love from France ^^


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Apr 26, 2013
As Mastaba said, the pins wiring and connector are not standard, plus, they are glued. So i cut the end for it and plugged it with dupont connectors in the new ones.
The original fan connectors are standard, just not in modular PC fans. They're called JST-XH and look to be 0.1" (2.54mm) pin pitch. These connectors are used in all ranges of electronic gear as board to board and board to device interconnects.

If you need some pre-terminated connectors with leads:


May 31, 2020
Hello Guys,

I bought a 9SX3000IRT2U (online double conversion) which has the same problem than 5PX2200/5PX3000. Even when batteries are full, fans are running too fast, too much noise.

I have an old EATON "Evolution S3000 2RTU" (3 fans too), speed fans decrease a lot when battery are full. Very different behaviour for same power (3000 VA), I don't understand why.

I noticed that 9SX3000 has only 2 fans, then I think using 31 cfm (Arctic) instead of original (45 cfm) should be not safe.

I plan to change 9SX3000 (2 fans) for 5PX3000 (3 fans) , and get 2 x EBM. Do you think using Arctic 31cfm should be OK, even when temperature is high (when charging batteries in summer for example).

Thank you for your advice.