Questions about my variac

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

Original poster: "Bill Vanyo by way of Terry Fritz <twftesla-at-uswest-dot-net>" <vanyo-at-echoes-dot-net>

I have a used variac with the following on the label:

General Electric VOLT-PAC
Mod. No.: 9T92A5052
Input: 250V  50/60HZ  3 PH
Output: 0-250V  50AMPS

It has several connection terminals, labelled as in the following
diagram:

http://hammer.prohosting-dot-com/~vanyo/images/variac.jpg

Right now I just hook my house line to 1 and 4 (4 being the hot wire),
and the line from my NST's to 1 and 3, so I can send 0 to 120 volts to
the NST's.  It seems to work.

Does anyone know how else this can be configured?  For instance, if I
had 240 volts in, and wanted to draw from 0 to 120 volts out?

Also, when I turn the dial to the extreme high end, there is some arcing
where the brushes make contact, and at that spot there seems to be a
carbonized area of the black stuff that encases the coils there.  Is
there a way to fix this?  Can that carbonized stuff be brushed out and
filled in with some appropriate insulating material?

	Thanks,
	Bill Vanyo