Re: Series-ing Potential Transformers

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

Original poster: G <bog-at-cinci.rr-dot-com> 

Hi Dave,
Wouldn't it be less stressful on the insulation if you just run the 
transformers series opposed like an NST? Just ground one side of the 
dual-bushing PT and swap the AC input wires. Now you have 7200 volts on 
each terminal, opposite polarity, for 14,400 total.

Regards,
Gregory


>Hi Bert, all,
>
>Bert is correct. I have (2) butyl rubber 7200 volt PTs.
>One of them only has one HV bushing terminal while the
>other has two. As I mentioned in an earlier post re-
>garding this issue, I series the two together for 14.4
>kVAC out to my HV rectifier for up to 20 kVDC to charge
>my 10 kJ can crusher/quarter shrinker capacitors w/in
>20 seconds. I run the single bushing one from ground and
>take the "floating" 7200 volts off of the single bushing
>of it and run it "piggie-back" to one side of the double
>bushing one, making sure it's properly phased and get 14,400
>volts out of the second PT's second bushing. I have had
>no problems with this setup as I know the BIL rating of
>both of the HV terminals of the second PT should easily
>hold off up to 14,400 volts.
>
>David Rieben



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