RE: Why do TC's use line filters wired in reverse

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Gary.Lau-at-compaq-dot-com>

No, I maintain that EMI filters are very much asymmetric and that the hookup
direction is critical.  Look at the schematic.  The case terminal is
connected via 2 capacitors directly to the LOAD terminals, and not to the
LINE terminals.  This makes it asymmetrical.  If you connect the filter case
to the 3rd wire AC ground, and the LOAD terminals to your NST, the HV
transients will be coupled directly from the NST primary (via the
aforementioned capacitors) to your 3rd wire ground, which is a bad thing.
The common mode chokes never come into play.

Connecting the LINE terminals to the NST puts the chokes between the NST and
the caps to the case/ground, and you now have an effective low pass L-C
filter between the NST and the hot/neutral/ground.  Again, please reference
the schematics on http://people.ne.mediaone-dot-net/lau/tesla/emifilter.htm.  If
this filter schematic is not the norm, please correct me as I would hate to
be the one spreading bad advice, but I'm pretty sure it is.

Gary Lau
Waltham, MA USA

>Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Mddeming-at-aol-dot-com>
>
>Hi All!
>Terry's right. I went through the entire CII Corcom catalogue and there is
>not one asymmetric filter, although all are marked "in" and "out". The only
>difference I've seen on any filter is that some have a ground terminal only
>on the "out" side. But ground is ground as long as it's not the RF ground,
so
>do like Jonathan Swift finally recommended in Gulliver's Travels and break
>the egg on the" convenient end". It doesn't make any difference, or as they
>say down here in the hills, "She don't make no darn diff'rence nohow"
>
>Matt D.