[Milsurplus] 400Hz fan run(start?) cap help needed

[J. Forster]

> I have some gear with small 24 volt 400 Hz fans installed.  I had one of
> the fans seize - taking with it the fan inverter board - and have yet to
> find an exact replacement.  One replacement of the same series (Rotron
> AXIMAX2HT/990YH) I found was 48volt 400hz.  However, the capacitor
> specified for this fan is 0.68 mf, where the 24 volt cap was 12 mf.

==============

Are you SURE? 12 uF is awfully big for a small fan at 400 Hz. IMO, it's
more likely to be 1.2 uF.

-John

==============

> One option is replace the things with DC fans, and have found some with
> similar pressure and flow specs, but I'd like to replace the fan in one of
> these amps with something close to original so I can compare various
> circuit temps between the two types of fan. (I can place thermocouples all
> over the place and compare temps, fairly easy)
>
> Any comments on running this fan at a reduced voltage?  What would you
> recommend for the cap value if ran at 24 volts rather than 48?
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