Ok lets get this in perspective..
3phase and neutral generator,, RCBO on the supply out.
Earth and Neutral bonded at source..
A fault occurs somewhere on the cables from the generator, as you say, a phase cable trapped in a metal door.
Nothing is going to happen unless the door in bonded to the earth supplied from the generator. I agree..but in therory you wont receive a shock because the generator is not connected to the Mass of earth, even though the door maybe.
So you say take an earth stake from the generator earth and stake it in the ground, in so doing you connect the generator earth to the mass of earth.
Now.. are you saying that this will now, if the door becomes live trip the RCBO??
Well i say it wont,, purely due to the fact that the resistance of the return path to the generator will be to great..
Now i am not the brightest button in the box but i am only trying to get this clear in my head, i still cant see the point..
any one else out there got any ideas on this
Pheww!!
