Re: Pole Transformer Re-Winding for Higher Voltage

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

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

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, August 03, 2003 10:27 PM
Subject: Pole Transformer Re-Winding for Higher Voltage


 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<dhmccauley-at-spacecatlighting-dot-com>
 >
 > I recently acquired a 4800V Pri, 240V Secondary 10kVA Pole Transformer
from
 > a friend of mine.  Does anyone have any experience as far to the
 > possibilties of
 > re-winding for higher output voltages.  Concerns would obviously be
primary
 > to secondary insulation, and core saturation due to higher voltage swings
at
 > 60Hz.

Core saturation should not be an issue if you leave the secondary winding
alone. The problems you will have are:
- the core and coil are heavy, and hard to work with. I battled one, and I
got oily and cut up.
- the primary and secondary may be on one coilform. If so, it's likely the
HV winding may be on the inside of the secondary, meaning you have to
destroy the whole coil to tear out the primary.

If this is not a problem, you'll find the core is a step-lap type, held
together with several steel bands. I've tried to take some of these apart,
and it's not easy. You have to keep the U shaped metal strips in order,
otherwise the core will not go back together again.

The paper in the transformer is some high density kraft paper or Nomex
paperboard (really plastic, not paper). The windings may be aluminum, so if
you use copper,  may more space for extra insulation, which is good.

KEN