Re: Variac faults: what to look for

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

Original poster: "Crow Leader by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-lists.symmetric-dot-net>

 > Original poster: "Scott Hanson by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<huil888-at-surfside-dot-net>

[cut]

 > Very old ('40's vintage) variacs may be found that did not use a slip ring
 > arrangement, but instead used a heavy asbestos-insulated cable that
wrapped
 > around the shaft two or three turns and connected the wiper terminal to
the
 > moving brush-carrier plate. I replace this cable with a piece of
 > fiberglass-jacketed high temperature aircraft wire, exercising the usual
 > cautions with handling of any asbestos-containing material.

Some companies like Staco Energy still use the wire on larger
autotransformers.

KEN