Here, the soft start is wired up. Paralleled 25 ohm, 50 watt resistors
used. Since there is a total of 125 uf for the filter cap assy, the step
start has to be done very carefully, with the requisite delay...typ 5-10
seconds. 12.5 ohms is used because if say 25 ohms used....the B+ will
come up to almost max, but won't reach max, since the magnetizing current
on the paralleled plate xfmr's primary's will still flow through any step
start resistor...creating a V drop across the step start resistor
assy....so you never get the full 240 vac applied to the xfmr's primary.
Once shunted, you end up with a secondary surge. To minimize the
secondary surge, a lower value is used for the step start resistor assy.
Regardless of value, when T=0, you always end up with the full 240 vac
dropped across the resistor assy.
Paralleled 4 ga teflon wire used. Mercury contactors used. I found a
pair of 250 amp supercon connectors, cheap, on ebay, so notified Scott
asap....and he snagged em. These go on the power cable ......and plugged
into the mating (existing jacks) on the back of the HV supply. This supply
gets a bit more complex, since the pair of identical 7.5 kva (5300 Vac)
plate xfmr's will reside in a separate cabinet. The HV supply is getting
there.....albeit slowly, due to time constraints.
https://www.youtube.com/watch?v=-BpADwJMbOk
Note you can turn on the close captioning...and also the entire
transcript.
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