This has always a worry to me,, here in the uk the flex that supplies electric lawn mowers is always 2 core.. if the blade slices thru the flex with out any contact to earth the RCD will remain on, it is unlikley that the fues would blow because of the speed of the blade,,

the worst that could happen is the gardner with his wellies on could place his finger on the bare flex and recive an electric shock, straight across live and neutral,, rcd would still not trip..

i feel for the cost differance manufactuers should use 3 core flex,,

Thoughts??