Re: Complying with Australian regulations

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

Hi Peter,

On 22 Nov 2003, at 12:36, Tesla list wrote:

 > Original poster: "Peter Terren" <pterren-at-iinet-dot-net.au>
 >
 > Had a visit from the electrical inspector from the Dept of Energy
 > Safety here in Western Australia.
 >
 > This occurred as some kid showed my website to his Dad (from the
 > Dept).
 >
 > Basically I passed!
 >
 > Here's how. In WA you are allowed to wire a plug and no more unless
 > you are an electrician.  However, the Dept is only concerned up to the
 > point when the mains is dropped down to 50VAC (or 110VDC). Everything
 > after that is OK even if you step it up to 240V it seems or in my case
 > up to 500kV.
 >
 > So for the inspection I connected one arc welder to step down 240 to
 > 50V 120A then another to step them up again to 240V to run my 4 MOT
 > supply for the Tesla coil.  (Home arc welders output 48 - 50 V to be
 > legal).  Actually with losses and a slight voltage difference between
 > the welders I get about 210VAC out.
 >
 > Presumably this can supply other home made 240 V mains equipment.
 >
 > I also had to satisfy him that I knew about safety and wasn't making
 > an income from it or doing public displays. I aslo demonstrated
 > Ignition coil supplies and flyback transformers all running off low
 > voltage as well as a van der Graaff generator. No problem.
 >
 > I didn't demo my other HV supplies or NST supplies but presumably OK
 > if passing through 50V. The OK still has to be confirmed from Perth
 > headquarters.
 >
 > Hope this helps other people in Australia.  ? anything similar in the
 > US/UK.
 >
 > Peter (Tesla Downunder)
 > <http://members.iinet-dot-net.au/~pterren>http://members.iinet-dot-net.au/~pte
 > rren

As a coiler from further downunder I can only comment that this
proves the law to be a complete ass, founded on some fundamental
misunderstandings about electricity. Voltage matters  only as a
function of (real) skin resistance - i.e. 50VAC might allow one to
get away with connecting onself across it if the the skin is dry and
calloused. So what happens if the skin is wet? It appears that
isolation of the mains via a transformer doesn't figure in the real-
world considerations of what is safe and what is not, even if it is
written into law. I'm surprised that 110VDC is considered "safe".
That is around SQRT(2) higher than the peak allowable AC voltage. In
NZ, the defined "extra low" voltages are 32VAC and 50VDC. I don't
suppose generating 100kV -at- 50 HZ from a bank of 1000AH lead-acid
battteries wired for an inverter supply voltage of 48V could in any
way be considered "unsafe".

Malcolm