Re: NST protection and grounding

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

Original poster: "WIZZARD . by way of Terry Fritz <teslalist-at-qwest-dot-net>" <pbobyk-at-hotmail-dot-com>

A safety gap alone will not protect an NST.
Capacitors of greater than ( a certain value ) to ground to filter out RF 
back to the NST can actually cause the NST to fail. I have heard that 
series coils for each leg of the NST are the best protection, coupled with 
the overvoltage spark gap can be effective,
BUT.....

I have two 15Kv/30mA that have suffered great damage by protection circuits 
that could have been avoided if I ran without protection at all.

I have unpotted and checked out rewinding an NST and I am intimidated by 
the fine windings of the secondaries! Get past the messy tar and count the 
hair windings per layer to rewind the transformer and well... I gave up. I 
would not recommend this to anyone.

An adequate protection circuit is REQUIRED for people like me who cannot 
afford to buy a NST every so often when one fails, for any reason! LOL!









>>Original poster: "Kurt Schraner by way of Terry Fritz

>>Hi,
>>
>>Elementary Q's, but I need help from you experts:
>>
>>1.) How important is the grounded center tap of the safety gap, when 
>>using a Terry type filter? Function of the center tap? (My SRSG has only 
>>a single safety gap).
>>
>>2.) What are the possible (-and probable-) consequences of a missed 
>>grounding at the center tap of a HV center tapped NST?
>>
>>3.) The old Q:
>>     Where should the NST be grounded: RF- or line-ground?
>>     Here my guess:
>>In order to protect the NST, it is better to connect to the line-ground, 
>>because, by that way, the voltage difference between the line neutral 
>>(connected to the primary)and HV-center tap is minimized. But, on the 
>>other hand, in order to protect the line (-and what's connected to it), 
>>from incoupling of ground strike noise, it is better to use the RF ground.
>>
>>Or: I'm missing something?
>>Thanks for your help!
>>
>>Kurt
>>
>>
>
>Hi,
>
>sorry for making more questions and dont answering, but... I have got 
>ground connection screw in my nst and is it center tap of HV or maybe only 
>connected to the core.
>
>This is tecnoservice NST 10/35.
>
>hardtmuth
>
>
>

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