[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Secondary Circuit Ground Fault Protection



Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Jeremy,

If you have one of these new transformers, please try it!!  The goofy stuff 
can be easily defeated* but I am not sure anyone has tried them straight 
yet.  It would be fascinating to know if they still will work as is.

*Just take the cover off and you will get the idea ;-))

Cheers,

         Terry


At 01:09 PM 4/21/2003 -0700, you wrote:

>Has anyone used an NST that has a secondary circuit
>ground fault protection built into it?
>
>New Allanson transformers have apparantly have these
>built in, and as far as I can guess they detect
>shorts to ground on the secondary side and cut
>the power if that happens. (Just like the outlets
>in bathrooms and kitchens.)
>
>I was wondering which "ground" these circuit
>protectors
>are referenced to -- the AC mains ground or the
>NST ground reference (secondary center tap)
>
>I don't connect the AC mains ground (ie green/bare
>wire) to my NST's but I do install saftey gaps
>between the secondary center tap ("NST ground" - zero
>voltage reference) and hot secondary connections.
>(Part of the Terry RC filter)
>
>I am concerned that arcing here (ie spark gap
>fails/cap goes overvoltage) will trip the ground fault
>protector
>and shut the off the power. That wouldn't be a bad
>thing in theory, but I do expect the occasional
>safety gap spark during tuning and adjustment.-- is
>this GFCI going to be a pain?