Looks like your recommendation is going to work AOK, Bob.
With 110 on primary leg A, I wired in primary leg B through a light bulb
(to limit current if necessary). Even though I can measure about 31 VAC
across the light bulb contacts before I screwed in the bulb, there seemed
to be negligible current through it when I screwed it in, so I shorted
across the light bulb and no problemo! I now have two primaries activated
with no apparent transformer heating or abnormal current consumption! I am
surprised, but will not argue with success.
Checking voltage on the filter cap I got 451 with only one primary leg
activated, then 548 with both. This is with 110 on the primaries. When I
put the full 220 on it, I think it will be about right. I am hampered a
little by not knowing the exact voltage it would put out in normal 3-phase
use, but I know the AC ratings on the transformer, so can make a good guess
about the DC voltage.
I may have to add more filtering later, but that is another story, and one
I can write by myself. I haven't put a load on it yet. If anything strange
happens then, I will report it here.
Thanks for the help.
Jerry W4UK
At 08:01 PM 11/13/2001 -0600, Bob Alexander wrote:
>Hi Jerry,
>If the delta primary is strapped externally for delta configuration, try
>placing
>two of the primary windings in parallel and leave the third winding
>disconnected. I did this on a plasma reactor p/s and it worked quite well.
>Leave the Y secondary as is.
>Insulate the third winding leads. The output voltage with 220 applied
>should be close to the original level.
>Bob, W5AH
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