Re: 110KV BIL?

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <wysock-at-ttr-dot-com>

Ray,

BIL stands for "basic impusle level".  It is an IEEE standard, for
impulse voltage level (withstand) peak voltages in a (simulated)
lightning strike.  Whereas the insulation of a P.T. may have a
110 KV BIL rating, unless you have an (unususally large) P.T.
i.e., larger then a nameplate rating of 1,500 VA, I would NOT
connect two units in series (on the high voltage side).  14.4 KV
is more then ample to drive any medium-sized Tesla coil.  You
will, however, benefit from PARALLELING the two units
(assuming they are identical units with the same power factor
and the same nameplate impedance specifications), and of 
course, you must be SURE to PHASE these two units the
same, both on the low and high voltage sides.  Then if you have
a large enough (primary tank circuit) capacitor, you will be
able to take full advantage of the additional P.T. transformer
current.  Alternately, if you are only running about 0.01 to 0.03
uf in your tank, still, the parallel configuration of the two
identical P.T.'s means you will never have to worry about
"smoking" them, due to over driving the low voltage winding
with excessive current.  Good luck to you!

Best regards,
Bill Wysock.

> Date:          Tue, 15 May 2001 20:58:13 -0600
> From:          "Tesla list" <tesla-at-pupman-dot-com>
> To:            tesla-at-pupman-dot-com
> Subject:       110KV BIL?

> Original poster: "Ray Haynes by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<ray.haynes-at-home-dot-com>
> 
> On a potential transformer what does the BIL rating mean? My only guess it's
> the breakdown voltage from the high voltage winding to either the case or
> low voltage winding. Is that correct?
> 
> If that is true then if I had 2 potential transformers (120 to 14.4KV) each
> with 110KV BIL then I could connect the HV sides in series (for 28.8KV) and
> not worry about breakdown from either high voltage winding to anywhere (case
> or low voltage winding) caused by the transformers themselves (excluding any
> tesla related arcs)?
> 
> 
> Ray
> 
> 
> 
> 
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