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Re: [TCML] NIST High Voltage Laboratory Testing / Safety Reference



You betcha, and is a real problem in industry.
Why do 300+ qualified electrical folks get killed annually
by electrocution or arc-flash, arc-blast events?  Not because
their lazy, but working on energized circuits (done it xxxx times
before and nothing happened, but today Murphy showed up.

Much is these requirements is to protect you from YOU,
and shield you if Murphy (or bad luck, timing, whatev)
happens.  It's no secret we are often times pushing
electrical equip way beyond OEM specs, so sudden
failures, sometimes spectacular, should be expected.

On Wednesday, August 20, 2014, mddeming--- via Tesla <tesla@xxxxxxxxxx>
wrote:

>         Interesting and highly informative document. I guess the fewer
> kilo-dollars one has to invest in redundant safety systems, the more
> responsible, careful, and aware one has to be.
>
>
> Matt D.
>
>
>  "Dune buggies don't come with 5 air-bags."
>
>
>
> -----Original Message-----
> From: David Sharpe <sparktron01@xxxxxxxxx <javascript:;>>
> To: Tesla Coil Mail List <tesla@xxxxxxxxxx <javascript:;>>
> Sent: Wed, Aug 20, 2014 7:13 am
> Subject: [TCML] NIST High Voltage Laboratory Testing / Safety Reference
>
>
> Truly excellent reference for use when designing
> medium or high voltage equipment or performing HV lab work,
> from NIST.  This document was referenced in a recent
>  EDN e-blog.  The great thing about this document is it
> is succinct, brief (9 pages), specific, and to the point.
>
> http://www.nist.gov/el/isd/mmc/upload/high_voltage_rules_revised.pdf
>
> One recommendation is the requirement of having "2"
>  separate operations to turn on high voltage; this requires
> at a minimum a Main Disconnect (Lockable Safety Switch)
> and a start-stop push-button station with seal in contactor.
> This requirement supports my contention you should never
> "instant on" high voltage equipment.  YMMV, but I've seen
> catastrophic, spectacular failures doing this.
>
> The additional requirements of a RTZ (Return to Zero) interlock,
> on all  HV equipment is very interesting, and I'd bet less then
> 5% of the amateur Tesla Coil HV equipment built worldwide
> has that feature.  But RTZ could save your life, and possibly
> infrastructure too.  I am designing a solid state power controller
> with integral ballasting and current limit regulation (240V/100A)
> utilizing AC Chopper technology that I have decided to incorporate
> this feature into the design.  An additional requirement is a
> flashing red beacon with the presence of High Voltage (if it
> doesn't interfere with testing).  If the SG is not firing, you have
> no outward indication that there is high voltage present, which could
> have very dangerous consequences.
>
> I hope this document is useful to the Tesla Community
>
> Best Regards
>
>
> --
> Dave Sharpe, TCBOR/HEAS
> Chesterfield, VA USA
>
> Sharpe's Axiom of Murphy's Law
> "Physics trumps opinion!"
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-- 
Dave Sharpe, TCBOR/HEAS
Chesterfield, VA USA

Sharpe's Axiom of Murphy's Law
"Physics trumps opinion!"
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