Hi Alan, Electrical separation (isolation transformer) and RCD are two different protective measures, there is little point in using an RCD with a fully floating supply as it won't detect an earth fault because there is no potential difference wrt to Earth.
If you happen to come into contact with two current carrying conductors at differing potentials from the same source, or commonly connected whether via earth, chassis or other means then you will always get a belt, regardless of *any * protective measure applied.
I am going to leave it at that because we have had many, many, sometimes heated discussions over the years with the inevitable thread closure that usually follows. I will respectfully bow out now.
