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Old 09-14-2021, 01:26 AM   #46
Join Date: Feb 2021
City & State: Minsk
My Country: Belarus
Line Voltage: 230VAC 50Hz
I'm a: Knowledge Seeker
Posts: 42
Default Re: Powerware 9120 Online UPS

Originally Posted by Behemot View Post
Don't bother with the large caps, those rarely fail (unless there's like 80+ C and you use for for decades 24/7).
You can try to replace KME with LE,
thank you
It seems that Nippon LE just 100F as maximum for 25V.
There is also a couple 220 F onboard.
I will try to find several different low esr capacitors with 8-10k Hr service life and manually check the best low leakage current.

I think UPS has some kind of fun regulator - noisy and super noisy modes :-)

There are 2 fans onboard - each has 2 wires connected in parallel so I hope my trick will work without faults fan on a display. I am going to install 4-7 fans and regulate their rpm automatically based on nearest radiators temperature. The power of all fans will be 2-2.5 times higher at full speed, my idea is to reduce rpm in standard UPS mode and in case of high temperature inside - temporary increase air flow and after quick reducing T then return to less noisy mode.
I never used online UPS before and I found at least 2 negative points:
1. energy consumption significantly higher compared to mine line interactive UPS
2. because of the first point, the fans work very loudly to prevent the temperature of the components from exceeding the allowable limits

In parallel with the adjustment of the fans, I will try to cover the space around the UPS with car noise insulation.
AleXis6 is offline   Reply With Quote