Re: MOT V stress was Re: pole pig

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Allanh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <allanh-at-starband-dot-net>

I agree that at least the total supply voltage is across the sec.for some
period of time, and would submit that there may be even higher, that is
kickback spikes, across it as well. I've had no success with using the sec.
of  a MOT (they fail from arcs) as an inductor and I suspect it has to do
with high freq. spikes from the TC pri. After all, we are asking it to block
those hf freq. and isolate the TC pri. from the PSU so the voltage may rise
much higher than the supply levels.

allan

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, August 17, 2002 5:05 PM
Subject: Re: MOT V stress was Re: pole pig


>
> Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<tesla-at-paradise-dot-net.nz>
>
> Hi
> Wells
> I believe you are correct but I would comment.
>
> The very outside of the secondary does come back close to the EI core.
> Having said that I select my MOTs for the maximum clearance in this area.
> I am guessing that as the very inner part of the MOT does not require much
> insulation as it is normally near Gnd potential the insulation near the
> inner is not as good as the installed insulation at the outer which is
> required to hold off 2kv for long periods. Pushing this a little to 6kv
does
> not pose problems either in air or oil. Mine have never failed in this
area
> in MOT driver PSU service.
> The point I'm making is really that the very inner part of the MOT sec
> (which you can't get at or see) is not subject to full stress.
> I've not used a MOT as a charging reactor and I would imagine this is
> extremely stressful on the insulation as the total coil primary voltage is
> across the secondary for a period
>
> Best
> Ted L in NZ
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Sunday, August 18, 2002 10:54 AM
> Subject: MOT V stress was Re: pole pig
>
>
> > Original poster: "Wells Campbell by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <wellscampbell-at-onebox-dot-com>
> >
> > Ted,
> >
> > I lost the post before I could reply, but if I'm not mistaken, while
> > the voltage between the inside of the MOT secondary and it's core in
> > a 6 MOT setup may be ~ 4.4 KV, the outside of the sec. winding comes
> > close to the outside legs of the E segments, not free space, and are
> > uaually insulated the same as at the inside leg; at this point, would
> > the stress (Sec to core to primary) not be around 7 KV? That's where
> > one of mine arced over when I tried to use it as a charging reactor.
> >
> >
> > just checking...
> >
> > cheers
> >
> > --
> > Wells Campbell
> > wellscampbell-at-onebox-dot-com
> >
> >
> >
> >
> >
> >
>
>
>
>