Changing PSU fan help with fan amps

Discussion in 'Modding' started by drunkntigr, Oct 8, 2020.

  1. drunkntigr

    drunkntigr Member

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    Have a 620W Antex High Power Gamer

    Works 100% no issues, just want to make the fan quieter (no, it's not even loud)

    Annoying think the fan in there is 135mm, I'm just going to try and put a 120mm fan inside and just cable tie the fan on.

    Now the fan inside is a 12V 0.27A ADDA, I've seen people put in fans but as the operating amps are higher than the fan inside, e.g. 0.36A, the fans don't spin.

    I have a Noctua P12 and S12, each with 0.09A rating and 0.12A rating.

    If i put these fans in, will the fans get burnt out? Or should the PCB of the PSU supply just the amps required to run the fans?

    I have a 3pin to 2pin converter on order just in case someone mentions it.
     
  2. Butcher9_9

    Butcher9_9 Member

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    If the Amps are lower you are 100% OK. Its the voltage that matters.

    The fan will only draw what its needs. So if the board in the PSU can provide 0.27A then drawing less will not causes issues but drawing more might.

    Same as with your PC. If you PC has a 620W PSU does not means a PC that only draws 200W will get burnt out. It just only draws 200W.


    As for the 0.36A fan not turning. Did you test it out? I would say that 99% a 0.36A would work fine . I doubt the board is running so close to the red line that 10-20% extra would wreck everything. At he very least the Fan would for sure spin, its just that it might fry the board if its really so close to the max rating.
     
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  3. power

    power Member

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    just don't ruin the CFM, your PSU won't be happy running too hot over time.
     
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    drunkntigr

    drunkntigr Member

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    wisdom exists here. thanks.
     
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    drunkntigr

    drunkntigr Member

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    converted that system to just a spare web browsing desktop, doesn't even have a video card so would think it'll only be drawing 100-150W max.
     
  6. power

    power Member

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    nice, might even get away with passive for that.
     
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    drunkntigr

    drunkntigr Member

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    watch for Melbourne house fire on the news.

    hopefully these things cut out over a certain temperature i would think?
     
  8. mareke

    mareke Member

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    If you can afford it buy a PSU like my Corsair HX1000i PSU that I bought in the For Sale forum a few years back. The PSU is designed so the fan only turns on if certain extreme conditions happen (I'd have to look up what they are) and the conditions never occur in my computer. My Corsair HX1000i PSU may as well be fanless because the fan never turns on.
     
  9. power

    power Member

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    I've also got a Corsair PSU that is passive until a load limit is reached.
     
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    drunkntigr

    drunkntigr Member

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    Job done.

    Order a 2pin to 3pin adapter off ebay like $5 to save the hassle of converting the wires - some youtube videos were like 10 mins long lol.

    make sure the noctua fan nf-s12 in this case had less amps / required less amps than the existing 135mm fan inside - read many users had trouble with the fan not spinning, would assume the psu doesn't supply enough amps via the 2pin by default.

    the noctua s12 fan is: 12V 1.44W 0.12A (other noctua fans seem to be only 0.09A, this is an old S12)
    ADDA original fan is 12V 0.27A

    • Just used one screw to screw in one corner, then cable tied the rest using black cable ties.
    • Simply plug and play, wrapped the excess cable around the fan cage.
    • The original fan has a clear plastic covering 1 third of it, assumed it was so that air would blow more to the rear of the PSU and then blow the air out through the rear grills, the 120mm noctua i placed more towards the rear corner anyway so should be alright.
    • my only problem now is this being my old main pc now turned web browsing is now quieter than my brand new sff nr200p, fk, lol. Literally this thing is now dead silent. the noctua a12x15 and P12 fan in the top of the case and the 212 hyper x cpu fan make the itx case a lot louder than this now. ffs.
    • the psu is now quiter than the bequiet psu in the itx. blarg.

    3A12DB5F-7535-4591-80E2-778921333E38.jpeg 7B026859-3A38-4785-AFA0-1EB07E9C18B2.jpeg D9848CBF-119B-44FB-9425-B55EF18910C7.jpeg 29AA1E74-A8CE-4436-8794-B35C8591A95A.jpeg 1E87B253-1347-43E6-8549-07B505F646A0.jpeg
     
    Last edited: Oct 15, 2020
  11. the Fan-Man

    the Fan-Man Member

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    I've done this to a few power supplies, namely FSP ones. Excellent units that last 10-15 years but rubbish "power logic" fans.

    In your situation id recommend a 140mm fan. If the noctua fan you put in is one third the power and won't do anything when it ramps up. Secondly the gap created between the fan frame and the extra room of the original fan will ruin that airflow further.

    These PSUs are armed with fan fail detection on a 2 wire fan based on power draw so you're cutting it super fine if it runs with fan only drawing a maximum of a third less than the original.

    If I can find it, I had a spare one of these: https://www.pccasegear.com/products/34186/phanteks-ph-f140sp-140mm-premium-case-fan-black - if found you can have it for free plus post. Higher static pressure and up to 20cfm more maximum airflow. Only 2db louder than the noctua s12
     
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    drunkntigr

    drunkntigr Member

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    thanks. I've actually got 140mm fans lying around somewhere, didn't even think :| just assumed 140mm probably wouldn't fit in 135mm.
    sigh.
     

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