[sdiy] Question on 120v/240v fuses and PowerOne PSU

[harrybissell at wowway.com]

As long as the VOLTAGE rating of the fuse exceeds the line voltage, that
is SAFE to use.  You should use a fuse of the correct (specified) amperage
for the line voltage.

(its similar to capacitors, you can use a highewr voltage but the microfarad
rating should be correct).

Don't EVER use a lower voltage fuse (like a 12V auto fuse) fro a line voltage
application. They are not guaranteed to clear (open) safely. The voltage might
still arc through the fuse and cause trouble. 

THIS IS DOUBLY IMPORTANT at higher voltages... a 240V fuse will NOT protect
a 480V line...

H^) harry


On Wed, 29 Oct 2008 17:31:42 +0000, Tom Bugs wrote
> Hiya,
> 
> Using a PowerOne HAA15 supply, the fuses are spec'd differently for 
> 120v and 240v. -> 375mA for 240v (and 220v) and 750mA for 120v (and 
> 100v)
> 
> I have two bags of fuses to use (375mA and 750mA!) but I just 
> noticed that they're both spec'd at 240v.
> 
> For 120v should I use 240v 750mA fuses? Or do the 240v375mA fuses 
> give 750mA at 120v??
> 
> The reason for my confusion is that on pwr switches, for example,
>  you usually have a spec such as 3A at 240v / 6A at 120v.. Though I 
> just checked a bit on the 'net and it seems as though a 240v fuse 
> should behave the same at 120v --- in which case I do use a 240v 
> 750mA fuse.
> 
> Any help, please let me know - thanks!
> 
> Tom
> 
> PS -- a note -- I just found out (by testing with a step-down 240v-
> >120v trafo) that if you trim-up an HAA15 for +/-15v operation at 
> 240v you can swap the trafo input connections (as detailed in 
> datasheet) (and change fuse) to 120v operation and the output 
> voltage is still accurately trimmed! I wasn't 100% sure that this 
> would be the case, but I'm happy that it is!
_______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy


Harry Bissell & Nora Abdullah 4eva