Paul,
I can't personally speak for BS 7671.
What sort of length of run are we talking?.
But this argument came up here a few years back in a new house I was to hook up at work.
The Inspector called me to delay me turning up to hook up the pillar box end.
What had happened was the Electrician had used the Earthing Lead (or Main ECC) to earth the meter enclosure and the inspector had other ideas.
What the Electrician had done was stripped the ECC and wrapped it around the braised stud in the meter enclosure, without actually cutting the copper wires themselves.
All nice and tight once the washer and two nuts were added to the stud, what's the problem?.
Under the 1992 Regulations, I'm told, you have to run a seperate bonding conductor from the Earth busbar in the Main Switchboard, to the meter enclosure (6mm2 too + tags at both ends).
I really don't see the point in it to be honest.
Lets face it, how often in a safe installation, will that conductor actually carry any real fault current?.
If you wanted to be really sure that the connection was safe, you could cut the Earthing Lead and terminate the ends at the stud with two properly sized eyelet crimp lugs.
I have a sneaking suspiscion(sp?), that at one time, somebody did a poor connection at a board or the like with a Main ECC and someone got killed or injured.
That seems to be the way we make Regulations these days (ie: knee-jerk reaction).
I don't have a problem with using the Earthing Lead as long as the connection is made properly and is tested after the connections are all made.
