OK guys, this is recollection from 8+ years ago...
If I remember right equipmemt approved for use in a swimming pool by UL (not a fountain) has to have a split wound transformer with the secondary on an insulated bobbin. This is where the primary and secondary windings are either on seperate bobbins on a common core or are wound on an insulating bobbin with secondary insulation between the windings (windings side by side). This is opposed to primary and secondary windings right on top of each other. The core was also to be grounded.
The theory, I guess, is that a fault on the primary would be cleared by overcurrent protection (short winding) or by ground fault (short to bobbin) while the secondary was still insulated from the core and primary.
Again, trying to remember from a while ago...
