Re: MOT Wiring

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: coils@xxxxxxxxxxxxxx 




Tesla list
> Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>


> "Is your primary 120 or 240?  If it is 240, then you should have a nice
> 15KV unit.  Did you knock out the shunts in the transformers?"
>
> No I haven't knocked out the shunts. If a current limmiting ballast is
> required to limit current, why would I want to?

With or without shunts, you need a ballast with MOT's, if you are not
getting the list via email, then check out these threads in the Pupman
March 2006 archives (http://www.pupman.com/); MOT Shunts, and MOT Shunts?

> I have the MOT's aranged with each primary pair in parallel, and the 10V,
> (240V) across each pair. So like this I should still get about 12 to 15 KV
> out, right?

I put my primary pairs in series, and then the three primary pairs in
parallel,  because the individual trannies were designed for 120Vac, but I
wanted to operate at 240.  All secondaries are seriesed, and the secondary
network is center grounded.  Unless yours are in fact made for 240Vac, I
would not put them in parallel.

The problem with putting two 120V primaries in parallel, and then applying
240V, is that you are doubling the secondary voltage too (and probably
saturating the little cores when current flows and stressing the
insulation specs, which are already being stressed on the outer 4 units).
So two 120Vpri(parallel)/1800Vsec(series)  MOT's operated at 240V results
in 7200V secondary. So a six pack by that design would see a 21,000V
secondary (briefly, have a fire extinguisher nearby).  21+KV on a tranny
designed for 1.8KV.

You mention 10V across your primary,  for phasing, testing, and finding
your ratio, I recommend applying the low voltage across the secondaries
and meter across the primaries, that way your always stepping the volts
down, and you can arrive at the same information.


>
> "I arranged my 6 pack so those two wires were the output legs. "
>
> So rather than use the output tab that would normally be the 'high' side
> of
> the MOT's, I use the inner lead that was attached to the core. Wouldm't
> this
> put more stress at the cores? Well if this works for you, I   might give
> it
> a try.

Yes, that is exactly what I did, I did it that way because the original
outputs plugged right into my series network, and I needed long tails to
reach my ouptut bushings.  The core connections got new 18 awg tails,
packed in Phillyseal "ratseal" epoxy to keep them off of the core. The
cores are isolated from ground, so the voltage stress on the insulation
isnt as serious a problem.  You can do it either way.

I just ran my coil Sat. the 18Th in Needles, CA. and it was a blast.
Almost 8ft streamers.

-Thad Howard
> Thanks,
> Mike
> ----- Original Message -----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: <tesla@xxxxxxxxxx>
> Sent: Sunday, March 05, 2006 8:58 AM
> Subject: MOT Wiring
>
>
>  > Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
>  >
>  > I'm putting together a MOT 6 pack.The center xfm'rs will have the
>  > cores tied together. As I move out from the center the next 2 xfmr's
>  > will have there lower voltage side be the core. Is it necessary for
>  > me to remove this HV wire from the core, or can I leave them
>  > attached? I plan to submerge the whole thing in xfmr oil.
>  > Or as an alternative wiring scheme, should I think of wiring this
>  > like a single bushing pig. That is consider one outer xfmr's core as
>  > ground, and each adjacent xfmr as the next higher voltage unit? I
>  > hope I'm making myself clear.
>  >
>  > As always, THANKS!
>  >
>  >
>  >
>
>
>