Re: Preventing a REALLY expensive mistake.

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <mystuffs-at-orwell-dot-net>



Tesla list wrote:
> 
> Original poster: "Aleks Nowak by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <Aleks-at-sn2.co.uk>
> 
> > Original poster: "Metlicka Marc by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <mystuffs-at-orwell-dot-net>
> >
> > chris,
> > just my opinions below
> 
> > no way, keep single, install triple
> 
> It would surely depend on how the 3ph comes in. If they install extra wires
> and the old ones are inplace still then fine, keep both. But you will
> probably find that they send only 3ph in and you have to drop it to 240
> yourself

this isn't a big problem because in most cases i've seen, large
delta\wye transformers can be had at a reasonable cost. there was a
35kva on ebay a few weeks ago that went for $400.00 new. we have dropped
480 down to 240v at the point of need for most cases, with smaller 30 to
50kva dry transformers. 


> >


> >
> > use this for all rf grounding.
> Can't comment on this. It all depends on the surface area in contact with
> the ground. Some large buried metal plates about 2m underground would do a
> better job.

this does sound like a better option. and easy to do. 


> 
> >
> > >
>
> >
> > faraday type shielding of the room, conductive paint on the walls
> > sprayed over grounding buss along floors, grounded to rf ground points.
> >
> Marc, this isn't a flame, but I would not advise RF conductive paint, as
> IMHO conductive paint tends to just burn up on contact with a discharge, and
> would therefore need to be replaced on a regular basis (at great expense)

i've had great success using graphite for toroid coatings, no burning,
no flaking. graphite can be had for a cheap price and it can be mixed
with water and sprayed, we use it for high temp lube on mandrel bars at
the steel mill. what i was thinking is it could be sprayed onto the
walls and then coated with white wash lime or a dry fall paint. coated
up to a slight thickness it should pass any wall strikes or rf to the
buss along the floor. 


> 
> > >
> > > 4. I remember reading about garage coilers who have had discharges
> through
> > > the roof, can this happen on a solid concrete structure? (There will be
> > > classrooms under the H.V.L.)
> >
> > i wouldn't think so?
> Its is mildly possible. You should install some shielding (as another post
> said, nothing more than chicken wire is really needed)
> 
> >
> > >
> > > 5. I've heard of coils being mounted inverted from the ceiling. How is
> this
> > > done? Why? What are the advantages of this setup? Can it be used to make
> > > near vertical discharges to the floor?
> >
> > i would imagine this is so items to be tested can be placed under the
> > discharge point (pretty hard to mount a car on the ceiling?)
> Sounds good to me
> 
> <snip>
> > > Thanks guys!
> >
> > flame away,
> > marc m.
> >
> > >
> 
> Ok, thats my bit. Only based on what I know. If you know better (which I
> know many of you do) then let us know.

i don't mind at all.
marc