Harry Bloomfield brought next idea :
Graham. wrote :
Good greif, that's scary. Was there a secondary side fuse inside?

--

Any primary fuse could have avoided that. It looks like quite an old
transformer..

Er, it doesn't look as if the mains supply cable was overloaded (as I
first assumed), rather those mains cable were just damaged by the fire.

Sorry Harry, I meant secondary side fuse.

That transformer must be nearly 50 years old. If they still make iron
cored bell transformers, they are bound to have a thermal fuse
embedded in the windings. Same goes for extractor fans.
--

Graham.
%Profound_observation%