Re: Replacing fans in equipment?

["Andy Whitfield" <andywhitfield2002@xxxxxxxxxxx>]

I have to start with a few words of caution.....
UPSs are dangerous things to open up and work on.  Disconnect from
the mains, remove the batteries and press the ON button a few times
(to discharge the capacitors) before opening the UPS.
Also any modification of a UPS, could potentially, invalidate
insurance (such as building/contents insurance) if the UPS should
overheat, catch fire, etc.  I have to put this bit in, to cover
myself.  ;-)

Virtually all UPS fans are low voltage DC.  Only seen one with an AC
fan.
Any replacement fan will need....
Same voltage.
Very similar max current and/or max wattage (though can be less).
Same or better airflow.
Same direction of airflow (just a case of turning the fan around).
Same physical size.
And lower dB

As the UPS is double conversion, the fans needs to run all the time.
I can't remember if the fans in the 9120 are variable speed.
Paul, do they speed up when the go on batteries?

Andy the UPS Man
PS: I've got 2 of these UPSs left and 4 battery cabinets.  Plus many
other UPSs in stock.

--- In ukha_d@xxxxxxx, "Paul Gale" <groups2@...> wrote:
>
> I have two really good UPS's in my new node0 (thanks Andy).
>
> Trouble is, they have quite loud cooling fans which are the very
high performance type i.e. move a lot of air but are very noisy.
>
> I'd like to modify or replace them with something a little
quieter. I need to first check to see if they're mains or LV though.
>
> I was thinking it might be better just to mod them to reduce the
speed and hence noise a little, so is it just a case of adding a
variable resistor in series or is it more complex than that?
>
> Cheers,
>
> Paul.


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