SC846 / PWS-902-1R PSU mod

Stefan75

Member
Jan 22, 2018
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Switzerland
I'm running my SC846 in JBOD mode with HP SAS Expander and a shorted ATX pin.

I want to quite down the PWS-902-1R PSU.
The current fan is a Sanyo Denki 9CRA0412J505 Sun Ace 40x40x56.
It has 2x 3pin connector, so I guess the speed is controlled by voltage.

sun_ace_fan.jpg

What options do I have?
- resistor
- one or two standard 3pin fans (Noctua etc.)
- ??

I think the Nidec fan here is PWM (not 2x3pin): https://forums.servethehome.com/index.php?threads/neos-freenas-build.5907/

thanks
 
Last edited:

StevenDTX

Active Member
Aug 17, 2016
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1) It is very dangerous to open up a power supply and start modifying it!
2) I did try it and you wont be able to get a fan that reliably cools the PS, and is a lot quieter.
3) Just buy the 920SQ's.
 
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maze

Active Member
Apr 27, 2013
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1) It is very dangerous to open up a power supply and start modifying it!
2) I did try it and you wont be able to get a fan that reliably cools the PS, and is a lot quieter.
3) Just buy the 920SQ's.
+1 - you can likely find the sq psu at a decent price if you have a little patience
 

nthu9280

Well-Known Member
Feb 3, 2016
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San Antonio, TX
Other cheaper alternative pws-741p-1r and are fairly quiet. Just need to make sure it has enough capacity for your load.

Sent from my Nexus 6 using Tapatalk
 

Stefan75

Member
Jan 22, 2018
91
9
8
46
Switzerland
I replaced the Sanyo fan with a Nidec UltraFlo 12V 1A 40x40x56mm R40W12BS4AC-52.
The installation was quite easy, wire colors were almost identical.
It seems more efficient than the original and less noisy too. :)

nidec1.jpg nidec2.jpg