Re: PTs

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

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 4/14/01 12:46:09 AM Central Daylight Time, 
tesla-at-pupman-dot-com writes: 


>
> In the past I have connected an MOT directly to the wall as long as I didn't 
> draw an arc, nothing happened. Pull an arc, couple seconds later, tip the 
> breaker. Tried connecting the big PT straight to mains and 2 seconds after 
> plugging it in, BEFORE I drew an arc, it tripped the breaker. 
>
> POO! 
>
> Why? 
>
> help, I'm confused (as usual) 
>
> Christopher A. Boden Geek#1 



Hi Chris, 

Unfortunately, it sounds to me like your big PT has an internal 
short in the HV secondary winding. It certainly shouldn't be 
tripping your mains breaker with no load on the output, unless 
there's an internal short. And unfortunately, a butyl covered PT 
is virtually impossible to tear into to repair ;-( 

David Rieben