Re: Safety--NFPA70E and Flashover Clearance Info

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

Original poster: David Sharpe <sccr4us-at-erols-dot-com> 

Hi John

Tesla list wrote:

 > Original poster: "John Richardson" <jprich-at-up-dot-net>
 >
 > Hi Dave,
 >
 > I am glad that you brought this subject up, and was hoping that you could
 > offer some insight into my problem.  I am getting to the point in the
 > basement where the streamers are getting long enough to start hitting things
 > that they shouldn't be, ie house wiring.  I have moved everything as far
 > away from gas lines, wires, etc, but after having added another quick coiled
 > up piece of dryer duct, things changed dramatically.  While tuning, I went
 > from no output to tremendous output, with streamers longer than expected,
 > and therefore hitting the Romex in the ceiling.  I didn't expect this.  If I
 > run chicken wire on the ceiling, and ground it out, will this be enough to
 > keep things safe?  I think it would.  Also, what are the thoughts on a
 > dedicated line filtered 120v line for all coiling activities?  I DON'T want
 > fires, and I am at a level now that concerns me.  Up until recently, I've
 > been a firefighter and hazmat tech for various volunteer departments, and
 > having seen the aftermath of carelessness, I want to avoid it.
 >
 > Thanks,
 > John Richardson

It is a potentially (no pun) a dangerous situation to be running HV apparatus
in confined space.  That being said, I've run a magnifier spitting 60"+ sparks
in a garden shed of 12'x20' so I know the issues of limited work space
that you having to face.
.
4 square to inch hardware cloth or chicken wire mesh will work fairly
effectively to shield Romex branch circuits streamers.  I've also said
"scre.. it" and run circuits in steel armor BX (yes a pain in the butt, but if
grounded at both ends is  very effective in shielding 120V circuits).

Regards
Dave Sharpe, TCBOR/HEAS
Chesterfield, VA. USA

<<SNIPPO>>