"Sparks" wrote in message
...
Okay, I am confused!

As I understand it (Please correct me if I am wrong!) if you have a TN-S
installation (Earth supplied via the armor on the mains supply) then if
you install a generator, you cant rely on this earth. - seems sensible, as
the fault that has taken you off supply could be because your cable has
been cut.

I can't fully explain why, but if you are using a generator through a change
over switch then you must convert to a TT system with a local earth rod, and
have the generator floating N strapped to E.

Tim..