"BigWallop" wrote in message
...

"Welsh Bob" wrote in message
om...
As an occasional student of the wiring Regs, i've been wondering this
for a while - when there is a remote CU in an installation like in the
flat in this case, why is the connection made from the main CU to the
remore one made using armoured cable if its internal to the property.
Could the link be made with some hefty T&E?

It could be made with T+E but the armour gives a more secure earth bonding
because there is more of it and not just a thin inner core of bare copper.
Also, SWA Cable can be made more secure in any switch gear that is used to
isolate the remote mains supply. It is also more protected against
damage.
But there is nothing stopping anyone from installing a sub main with heavy
enough T+E.

Indeed, I have done it (yes it was inspected). There is also a separate
earth to the earth rod (in my case). Mine runs through the flat roof - I
guess if it was running exposed you might prefer armoured cable if it's
protected at 100A - you'd get a meaty flash off that in the right
circumstances.


--
Bob Mannix
(anti-spam is as easy as 1-2-3 - not)