OK, obviously this is two different days. Here I have a 208/220V; 440V, 5
horsepower 3-phase motor that I am experimenting with converting to an
inductive generator, powered by my Changfa S195 Chinese 12 hp diesel
engine. I'm learning here; I have never done this before. In both clips,
the motor is wired for low (208/220) voltage. That means it is wired
Wye-Wye (two sets of windings paralleled), whereas it would need to be
wired Wye (both sets in series) for 440V. Does this mean I could produce
440 volts with this setup? Undoubtedly. Rectify that to DC and power
the plate circuit of a tube linear amplifier without the big transformer
normally required. Add a small transformer for the low voltage stuff,
and this would make a good power supply for a legal-limit ham radio
So anyway, in the first clip I am using only one capacitor, and it is
the only capacitor I could find in the microFarad range that was rated
for high voltage AC. It has nowhere near enough capacitance; I think it
was 0.75 uF or something like that. As you can see, it didn't work.
Digging around in cyberspace, I found reference to C-2C wiring for this
specific purpose. Unfortunately the guy who was describing it didn't
have a firm grasp of what he was describing, having simply followed
someone else's directions. Thus, although it would seem that "2C" would
imply double the capacitance of "C", the narrative did not leave me with
a feeling of confidence that that was what he meant. Not disrespecting
the guy or anything, just telling it like it is.
So I searched further and ascertained that, indeed, 2C means 2C and not
merely C2. I found other stuff about it too, which gave me the
confidence to actually spend a bit of money.
Basically, it works like this: imagine a delta-wound, 3-phase motor.
There are of course 3 legs to which the power connects; L1, L2 and L3.
L1 and L2 will be the output. C, the first capacitor, connects in
parallel across L1-L2. 2C connects in parallel across L2-L3. Nothing
connects across L3-L1.
2C can be either a single capacitor of double the value of C or, as you
see here, two caps of the same value as C, connected in parallel.
So I went to everybody's least favorite online auction site and bought
three identical, new, 55 uF 440V motor run capacitors. As you can see,
this works; at least as far as producing voltage. Stay tuned, because
next I plan to load it with some heating elements to see what it can do.