Since many enjoyed the puzzle Henry posted the other day I thought I would add one that had me stumped.
A few years ago (NEC 1999) a contractor called me to check out a problem with a new inground swimming pool.
The problem was that the GFI receptacle kept tripping.
He then went to the sub panel and showed me that the breaker for the receptacle was in the OFF position. We then reset the receptacle and it tripped, with the breaker off.
What do you think was causing it ?
