Re: Putting two potential transformers in series

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

Original poster: Esondrmn-at-aol-dot-com 

In a message dated 12/21/03 11:52:13 AM Pacific Standard Time, 
tesla-at-pupman-dot-com writes:


> >Here is something that should be considered. The windings of HV Xfmrs are
> >rated at 2 and 1/2 time the voltage. Putting 2 xfmrs at 7.2 kv in series
> >means that the insulation should be rated at 2 and 1/2 times 14.4 kv. The
> >voltage rating of winding of both primary and secondary is the same because
> >of buck and boost possibilities of xfmrs. The original writer did not
> >indicate if the PT's were used or not.
>
>
>Al,
>
>If the transformer HV terminals are put in series, then the center point
>should be grounded.  This way the transformers will see their normal
>rated voltages.  The assembly should not be single-end grounded.
>
>John


I had a thought about this.  If you use only one P.T., I would assume that 
you would ground the case, as opposed to leaving it floating.  If you 
series two of them and ground the mid point where the two center H.V. 
bushings are tied together - do you then still ground the cases, or leave 
them floating?

Ed Sonderman