Sorry for the silence... been stupid busy.
It is good to see you have a formula for the turn per volt.
My observed rule of thumb is within 10% out from your proper equation... Generally if anything is within <10% electrically, all should be good enough to work very near properly.... the steel may be different too.
However, your test data says 1.15 volts per turn.... thats very different to the rule of thumb I use, and your formula... your steel seems to be very different, or your input voltage was low....... odd..... was the light globe still in series?
You should have had huge noise and very very serious heat, if you can blow your fuse once it is running ( 3 mins means 20 amps for a 10 amp o/load.... this is unlikely and will present as a 5kw heater.. I think you would notice this....) if the tranny is at fault... are you sure it cant be current leakage ( RCD triggering) rather than fuse.
If the tranny stays cold ( and I think it should with that many turns)... it is not from current overload... find something else doing it.
If the tranny gets hot... I have no idea at all, as there is enough turns there for your published core size to not be saturated for my money.
Only on turn on will the thing blow every fuse in the street, after that it is very very small power consumption comparatively..... in the milliamps, not amps... maybe 150-200 ma or thereabouts.
...............oztules