RE: 110KV BIL? (3 more questions)

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

Original poster: "Ray Haynes by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ray.haynes-at-home-dot-com>

If one side of the HV winding is grounded (see G.L.'s text from previous
posting below) then why can't I tie the cases together and pull the HV from
the 2 non-grounded HV bushings (assuming proper phasing)?

Also how does a 110KV BIL rating apply to a PT with only one HV terminal. I
assume that would be the max impulse in or out of that terminal.

These transformers are 120:1 types. With a BIL rating of 110KV it seems I
could run the LV side off 240V and get 28.8KV out and not stress it too
much. True?

Could some in-the-know take a look at a picture and offer any comments. They
don't look like I expected a PT to look (they have built in fuse holders and
no apparent HV bushings).
http://www.soap-lotion-dot-com/images/pt.jpg


Thanks All,
Ray

-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Wednesday, May 16, 2001 7:00 AM
To: tesla-at-pupman-dot-com
Subject: RE: 110KV BIL?

<SNIP>
If your PT has only one HV terminal, then it might be the case that one of
the HV leads is connected to the core of the transformer. You cannot series
such PTs as you are sure to have an insulation failure.

Godfrey Loudner

<SNIP>