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RE: Repost: NST VA Rating and Power Factor

Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>" <pkomen-at-zianet-dot-com>

Hello Jason

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Saturday, May 19, 2001 2:46 PM
To: tesla-at-pupman-dot-com
Subject: Re: Repost: NST VA Rating and Power Factor

Original poster: "Jason Petrou by way of Terry Fritz <twftesla-at-qwest-dot-net>"

>  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.
If you do the math (15000V*0.06A) you get 900VA - which is what it should be
for all 15/60 NSTs. I have no idea how you have got just under half that for
the franceformer ones... it is technically impossible :) I'd recheck the
labels, and if you are still lost measure the Vout of the secondary, then
short out the secondary and measure the current flow, and also measure the
current out of the mains socket. I think that the xfmr must be labeled
incorrectly. I dont know what the High Power Factor means - i'd check with
the company (or wait for other replies from the list

I have two NSTs, both 12kv at 60ma, high power factor (rated 400va).  It is
my understanding that the HPF NSTs have a built in capacitor to correct the
current lag due to the inductive load.  Adding the PFC cap reduces the input
current without reducing the output.  See also Terry's posts on PFC caps.
Adding PFC caps to a HPF NST doesn't make sense.  Maybe someone else can
give you the technical details.  Maybe I'll check the input current on these