Hello List,
I removed the filament transformer assembly (lots of HV wires for isolation)
and the cool but way to big Inductor (150H). There is a lots of free space
in the tank assembly now. Really only the (3) HV phase voltage wires are
coming out in the centers of the HV coils into empty space on the now roomy
side. I found the star point of the HV windings on the rear. Most of that
side is close to the tank wall and LV connections. I need to revolve it
(bring the engine lift back) to address where the additional "working
windings" that were terminated near the filament transformer, also .5" HV
wire that go around to the back. The unit is very modular and a tribute to
the Raytheon engineers for serviceability and clean design. Hell, it could
have come off an old aircraft carrier. I heard it was from a missile site,
but who knows. And I won't ask... it was decommissioned and surplus sold
back on the East Coast.
Having said and done all that, it looks like I may be back to the drawing
board. I back fed 120.9 volts and measured 1.328 volts on the LV respective
phase connections with my Fluke. I may try another meter as this has not
been calibrated in a long time, just to verify like results. That gives me
120.9V/1.328V = 91 to 1 turns ratio unloaded. That would be 91T * 208 volts
wye in = 11KV! per coil, well balanced too. Even running this at half
voltage is iffy. I suppose the interaction LV voltage control with a 3P
Powerstat stack must have inductive complex relationships to the transformer
and maybe the charging coil or is that isolated by the diode strings and
dequeing?
A few things come to mind which are out of my experience level: the HV coils
are 4 individual coils in series on each core... what would happen if one or
two were removed (I know half VA rating)? These would have to be
destructively removed, not really something I want to do. Parallel pairs
like in a generator would be awesome! - 2x current .5x voltage. The theory
of possible harmonics or eddy currents is out of my league but maybe doable!
This is much like a 12 wire Gen head wired in wye in that sense.
With the turns ratio and the core dimensions I should be able to calc the ~
VA of the transformer in the ball park, yes?
Open for suggestions,
Jim Mora