Variac frequency question

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ryanchrj-at-notes.udayton.edu>


Hello list,
     I recently acquired a stack of three 0-140V  20 Amp  400Hz variacs
(Technipower, type M20's).  I went to the manufacturer's website and found
that they can each be run with 60 Hz  60V input at 20 Amps without
problems.  My question is can they be run at 120V 60Hz  input with some
form of inductive or resistive ballasting on the input, or will there be
excessive core heating or saturation problems?  Thanks in advance for any
answers or suggestions.

Orteaze