Re: Danger, and I don't understand why.

On Thu, 12 Aug 1999 12:04:15 -0600, you wrote:

>Original Poster: ARSONIST01-at-aol-dot-com 
>> I
>>  turned off the power switch, unplugged the supply cord,  walked over
>>  to the gap, and pushed the wires apart with a plastic rod.  To my
>>  surprise a 4mm white spark snapped across the gap.
>RIchie, all,
>    This occurrence of an NST "holding a charge" is not uncommon. Last week i 
>was paralleling two Nsts( a 15/60 and a 15/30). after i successfully 
>paralleled them, i tried to hook them up on a jacobs ladder to see the efect 
>of a more powerful xfmer on a jacobs ladder. When i first hooked it up and 
>turned it on, nothing happenend so i turned it of. Like Richie, i thought 
>that once its off, its off and all charges are dropped s ince the nst isn't 
>supposed to hold charge. But i was dead wrong. When i touched the rods to re 
>position them, i got one hell of a zap from them.
>    This little incident wasn't posted to the list becuase i thought this was 
>a rare incident since i haven't heard of it before, but now i guess this 
>might be a common occurrence, again, I would like to know why this happens. 
>Getting shocked in Los Angeles,
Could it be the capacitance between the NST windings to the case ? Is
the centre-tap actually grounded to the case ? If not, it's
conceivable that a charge could sit on the windings (which are of
course well insulated) when switched off. This charge would of course
be between windings and ground, not across the windings.