Re: New Variac (and lots of ?'s)

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Marry Krutsch by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>
> 
> Hi All.
> 
>         I finally bought a Powerstat variac from C and H Sales.  I got it for
> $190.  Now the questions:
> 
>         The data plate says it's rated 270VAC and 56 amps, but the
windings are
> only 12 AWG.  I wonder if someone switched the name plate.  What's the
> deal?
> 
>         This thing has multiple taps, for 115, 210, 230, 250VAC, Common, and
> output.  The 210 tap was badly "abused" by the former user, so the
> solder connection between the 210 wire and the windings had melted!  The
> wire was just hanging there.  The surrounding winds had
> blackened/flaking insulation, so I just removed the 210 tap/wire
> completely, and scrubbed the damaged area with alcohol.  This is OK,
> right?
> 
>         There are a few errant winds sticking out above the rest.  I smoothed
> them a bit with SiC paper, but the wiper still makes "tinging" noises
> when it goes over them.  I know this will shorted brush life, so is
> there anything minimally invasive that I can do to correct the problem?

	I once repaired three bad turns of a 10 amp, 120 Variac between where
the brush had been sitting and the high side of the line [accidental
short from brush to neutral].  I pulled the old turns off the core and
replaced them with new ones of the same gauge.  Had a !-at-#%%!! of a time
getting all three into the space and reasonably flat against the core! 
I then took a fine file and was able to file the top of those turns flat
with the rest of the original ones.  Took it easy to keep from taking
much off the adjacent "good" turns.  Finished with #400 Wet or Dry, and
cleaned up the residual filings with an exacto knife.  That was over 30
years ago and the thing is still working!  The brush was in terrible
shape, but I didn't replace it at the time as it worked.  Later got a
replacement brush assembly from GR; I think it cost almost $2.50 way
back then.....

	By the way, that Variac was part of a bunch that the guys at C&H had
bought from the Ogden, Utah Army (or was it AF?) depot for peanuts. 
They'd been in a fire and someone had scooped them into a freight car,
where the water on them had frozen into a solid mass which had ashes and
junk in it as well.  Anyhow, C&H hired high school kids to clean them up
and repaint them with Krylon.  They were selling them years later.  This
particular one had been rejected as too scruffy to sell, and I got it
for a buck or so.

Ed