Re: Safety FAQ (Electrical Hazards)PLEASE READ!

>>From Esondrmn-at-aol-dot-comFri Jul 12 21:56:50 1996
>Date: Fri, 12 Jul 1996 14:00:40 -0400
>From: Esondrmn-at-aol-dot-com
>To: tesla-at-pupman-dot-com
>Subject: Re: Safety FAQ (Electrical Hazards)

>In a message dated 96-07-11 00:48:22 EDT, you write:

> Hmmm, I've often held a copper rod in the output sparks of a 4" coil. It 
>was only 1 kVa so I assume it was quite safe. On a larger coil, say 5 - 
> 10 kVa, would it still be safe to do this?
> I know Bill Wysock (spelling?) is renound for sitting atop a 1MV coil.
> The reason I ask, is because when I show my new coil, I would like to be 
> able to demonstrate this effect. The coil is running at about 2 kVa.
> Is this safe? (provided I am well insulated and in good tune)
> Thanks,
> Greg.


>I have attracted the sparks from my coil running at 2 or 3 kva using a metal
>rod.  There is enough current there to make my arm jump.  It is definitely
>best to stand on plastic milk crates or some other insulator.  You can
>definitely feel it when the sparks jump through your tennis shoes to the
>cement floor.  No harm done though.

>Ed Sonderman


Ed, I think you are literally playing Russian Roulette when you stick a 
hand held metal rod into the output streamer of your coil running at 
3kvA, while standing on a concrete floor!!!!!!!!!!!!!!!

When you start running these kind of power levels (or even less) some 
coils have a tendancy to form a corona or even send a streamer down to 
their own primaries every once in a while.  A grounded strike ring is 
often added around the primary to try to prevent this self striking 
streamer from hitting the primary coil and thus introducing a high 
voltage pulse into the 'bottom end electrics' where it could do 
damage to components.  These strike rails are not 100% effective.  
The streamer can still, and sometimes does strike a point downstairs that 
is part of the LETHAL 60 Hz circuitry.  When such a contact is made, 
any person also connected to a corona/streamer link to the secondary at the 
same time will, via the ionized air path, become connected to lethal 
60 Hz mains current.  You could try the trick you described standing on the
cement floor in your tennis shoes half a dozen times and live, or be killed the
very next time you try it.  The fact that the bottom of your 
secondary is tied to ground will not save you.

If you isolate your own body well away from the floor and any other 
potentially conductive objects in the vicinity, such as sitting or 
standing on an elevated insulated platform (I would NOT consider a 
plastic milk crate adequate!), then you will survive if 60 Hz is 
introduced into the streamer you are in contact with by the mechanism 
described above.  However, in setting up this insulated platform you 
must consider the path that may be taken from streamers that will 
re-emerge from your body and head off looking for other targets.  

In a safety warning I have about the potential hazards of Tesla coils 
mention is made of a stage lecturer while demonstrating how he could cause 
long sparks to come out of his fingers (by standing on a specially 
constructed coil), was electrocuted when the discharge created an 
ionized path to grounded overhead pipes supporting stage back drops, 
and the lower voltage but far more deadly 60 cycle current passed 
through his body along that path.  The name of this lecturer was not 
mentioned but I wonder if it is this deceased Transtrom fellow mentioned in 
Richard Hull's recent post.

I was dinking around once with a vacuum tube coil drawing 15 inch 
streamers to a hand-held, 10 megohm metal film porcelain resistor 
about a foot long while standing on a carpeted, elevated wooden floor 
in composition rubber soled dry shoes.  I inadvertently got the 
resistor too close to the primary tank coil (the top end directly 
connected to the 3 kilovolt output of the plate supply transformer) 
and the high voltage RF closed a path to the primary.  I felt an 
uncomfortable 60 Hz shock through my entire body.  Had that resistor 
been a solid metal rod I would have experienced a very painful jolt 
or worse, and had I been standing on a cement floor, I'd probably be 'worm 

I think the danger  of electrocution is just as real by making contact with a
hand held florescent lamp tube, as any solid conducting metal object.

I cringe when I hear of some body contact stunts proposed by people 
on this list!  The potential (no pun intended) for death is very 
real.   Be careful!

Happy (and safe) Coiling!, rwstephens