NEC and Tesla Coils

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>

It occurs to me, reading over David's stuff, and my copy of the NEC, that
really, the NEC (and the building code) applies primarily to permanent
installations.

For "portable equipment", NEC regulates some aspects.. things like power
cords, although it really doesn't aim at that "market". For instance, the
NEC isn't used to regulate PC's, Televisions, etc.

Also, for instance, NEC prohibits installation of electric sign equipment
operating at >1kV in a residence.  But, of course, the monitor you are
reading this on has a 15-20 kV supply that is unequivocally lethal in it.

In fact, there isn't much in the way of legal regulation for these sorts of
things. If you were to try and sell them, some jurisdictions (Los Angeles
County in California, for instance, but not Ventura County) require that all
appliances and electrical equipment be either UL listed, or UL tested and
approved, or approved by a recognized testing lab, etc...

But, since your average tesla coil isn't being manufactured for sale, these
laws wouldn't apply.

OSHA rules apply to "occupation"... i.e. work (if you are being paid or
volunteer...) and don't really apply to owner/operated.

I think that as far as safety regulation goes, "good engineering practice"
is it.

That said, I think that looking to the NEC and OSHA regs for guidance on
formulating a set of "design requirements"..  Things like grounding,
interlocks, bleeder resistors, current ratings of conductors, are all things
that you need a starting point for.

It's also important to make sure that you don't wind up inadvertently
getting yourself regulated... If you start out with the (publicly) stated
intention that you will "meet code", you're probably doomed to failure.
Which code? Which regulations? Who's doing the inspecting?  This is
definitely one of those things where you probably don't want to even start
down the path.

As it is, TC's are a hobby or avocation, not particularly more or less
dangerous than any other hobby such as metalworking, car racing, shooting,
sewing (every year more people are disabled in the garment industry than in
electrical industry, on both absolute and percentage basis).  None of these
activities are particularly regulated (except, perhaps, shooting) when done
on a non-business basis, other than common sense sorts of general laws
prohibiting you from creating a nuisance or hazard.

Everything is different if you are doing it for a profession (paid or not).
Then it will primarily be up to your insurance carrier and the places that
you show your coil.  Those of you that have done TC stuff for organized
haunted houses, school assemblies, film production, all know about what
hoops you have to jump through. (And they vary from instance to
instance....)