Re: Tesla Coil Safety (was RF Interference and Chokes)
Christopher, Ed, All -
It is my understanding that not using the house third wire ground is a
violation of the National Electrical Code (NEC). This is a safety code to
protect life and property and is mandatory in all states.
The following has been mentioned on this List several times before so this
is for the newbies.
It should be noted that Tesla coils cannot be UL rated and, therefore,
operating them is a violation of the NEC. Demonstrating Tesla coils in any
public building should be done only with the approval of the fire marshall,
wire inspector, lawyers, etc, etc. This is a hobby that carries many risks.
It is obvious that electrocution is not the only TC hazard.
Building Tesla coils is not illegal but operating them is. You should
operate your Tesla coil with the thought that if you goof up because of
inexperience you could be in deep trouble.
There are two major rules to follow before firing up that coil. Build only
small coils and learn as much as necessary about electricity so you can use
At 10:57 PM 5/13/99 -0600, you wrote:
>Original Poster: Esondrmn-at-aol-dot-com
>In a message dated 5/13/99 2:16:06 AM Pacific Daylight Time, tesla-at-pupman-dot-com
>> Original Poster: Christopher Michaelis <cmichael-at-xmission-dot-com>
>> Whenever I fire up the coil, my parents come out screaming and wailing
>> because the phones, tvs (cable, not antenna), radios, and intercom (which
>> is wired, not radio-based) are fuzzing about noisily.
>> I've only got 2 little chokes from radio shack on it -- what do the tesla
>> gurus recommend for protecting my 60hz line from feedback (is that what
>> it's called?)
>> Is there any other way besides a faraday cage to make my coil screw up
>> radios a bit less? I'm quite far away from my house, so the neighbors can't
>> be any happer than by parents.
>> Thanks in advance
>> Christopher Michaelis
>I would advise to make sure you have a good RF ground for the bottom of the
>secondary. Also connect the center contact of your safety gaps here as well
>as the case of the neon sign transformer - if that is what you are using for
>I also use a separate ground rod for my 60 hz ground. The case of the AC
>line filters as well as the case of the variac and any other items that
>should be grounded in the control system should be connected here. Nothing
>should go to the house third wire ground. I use this method of grounding and
>have very little interference on the television. The cordless phone is
>another story. It seems to be very sensitive. When the coil is running, you
>don't use this phone.
>You might also invest in some better line filters. I forget which mail order
>place I ordered mine from but they were relatively inexpensive (surplus).