sounds good, until you THINK,,,THE CORE IS GROUNDED IRON,,,that blows the fuse as you want.
leakage from primary to secondary winding is the problem,,,but that will never happen !!! in a properly designed transformer,,,or parachute !!
All it takes is a lightning hit on the overhead power lines in your neighborhood. Then you've got Ltning HI on the service phase conductor, Ltning LO (ground) on the neutral of the ljne cord.and lots of inductance to make L di/dt. I don't recall the exact insulation standoff value that UL requires for the varnish winding layer, but the number 1 kV keeps jumping into my brain, so if the lightning strike potential exceeds 1 kV it can arc through the varnish and paper wrap. Now if you calculate the induced L di/dt voltage appearing across 25 feet of #6 ground conductor, it comes out to just over 18 kVAC. It's more than twice that for a typical 6 ft #16 ga line cord.