Re: Repost: NST VA Rating and Power Factor

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Christopher Boden by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chrisboden-at-hotmail-dot-com>

>Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-qwest-dot-net>" 
><vanyo-at-echoes-dot-net>
>
>First, is the reposting of unanswered questions a problem for the list?

Not regularly, but lately it seems so.


>I'm sure this is a simple question for the experts here, but it seems to
>have sunk below visibility in the endless flow of posts.
>
>Anyway, again, my main question has to do with the "high power factor"
>label, and 495 VA rating on Franceformer 15/60 NST's, as opposed to 900
>VA rating on Jefferson 15/60's.  I've depotted a Franceformer in the
>past, and it didn't contain a PFC cap (do any NST's?), but I don't
>recall if it was labelled the same as these other two are.
>
>Why such different VA ratings on different 15/60 NST's, and does this
>have any bearing on whether anything is to be gained by using PFC caps?
>
>	Thanks again,
>	Bill Vanyo
>
>Original post was:
>
>  My power supply consists of three 15/60 NST's.  Two are Franceformers,
>  and are marked 495 VA, and also have "High Power Factor" on the label.
>  The other is a Magnatek/Jefferson, marked 900 VA.
>
>  Does this mean that I will have little to gain by adding PFC caps to
>the
>  supply?
>
>  When adding PFC caps, is there any point in placing them on each NST?
>  Since they're in parallel, I can just put the PFC caps in one place,
>  hooked in parallel, no?
>
>  Also, regarding the problem of tripping the house breaker (It was on a
>  15amp breaker, but there is a 20amp available that I'll try next time):
>  I've got a 240 volt line in my garage (20 amp breaker).  If I use my
>  variac to step this down to 120 volts, will I be able to draw more
>  amperage?  The variac is 240 volt 50 amp, and has multiple terminals,
>  and I think there's a way to use it as a stepdown (other than just
>  leaving the dial at 50%), though I'm not sure how to do this (asking in
>  another post).
>
>          Thanks,
>          Bill Vanyo




I could be completely talking out my area on this one, but I honestly think 
that the difference between the low power factor and the high power factor 
is an internal power factor correction cap. That would also explain the 
slight weight difference in the transformers, the cap displaces the heavier 
tar.

Just a thought.


Duck



Christopher A. Boden Geek#1
President / C.E.O. / Alpha Geek
The Geek Group
www.thegeekgroup-dot-org
Because the Geek shall inherit the Earth!



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