Re: MOT Wiring

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: coils@xxxxxxxxxxxxxx 


hi Mike,
here are some pics of my 6 pack powered coil, and the power supply.  I
grounded the inside cores, and left the HV on the core. I left the "next 2
xfmr's" HV tied to the core also, you just have to make sure that they are
insulated from ground and your case should be grounded.  I removed the HV
to core leg on the outer most xfmr's so they would not arc to the primary,
also the outside cores should be insulated from ground to prevent arcs to
ground.  All of my transformers are large and range from 1800vac to
2400vac.  I tried to match up pairs for equal voltage on the seriesed
secondaries.  I have had many successful runs at more than 4KVA apparent
power, it does'nt seem to do well over that though.  I think that wiring
it as a single bushing pig could give serious arc over problems at the
outside two maybe three transformers since they were only intended for 2
or so KV.  With it center grounded, the voltage stress is less on the
outside trannies.  My unit has an xfmr ration of .0175:1, so at 240V in,
the output is 13.7KV, and since I tried to match the secondary pairs, the
13.7KV is almost perfectly divided to ground.  So my outside trannies only
see 6.8KV (which is seriously testing the voltage rating of those two
trannies).  If all the secs were in series, with one end grounded, the
outside trannie would see the full 13.7KV, and I'm not so sure the winding
insulation would hold up.

Take your time and make sure they are phased together properly at both the
primary and secondary, that is the biggest challenge with putting so many
trannies together, also dont dow what I did and make it in a wood box, use
metal.

http://members.dslextreme.com/users/teslacoil/

good luck,

Thad Howard

Tesla list
> 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!
>
>
>