Length and Routing of Meter Tails

[acvc]

Scenario:

A mains head is in one end of a house, split phase. Second phase allowed on the basis of a second semi-separate dwelling to be built adjoining the existing house approximately 30 metres away frm the head.

Would it be permissiible to run the meter tails from the exisiting mains head, through the roof space of the house and under sections of floor to get to the new proposed dwelling, and into a the C/U + isolator of the new dwelling? I know there's the requirement to fuse protect the tails if they're over 3 metres. Do the tails require extra mechanical protection on a very long route such as this? I also realise a VD calulation will have to be done.

This would all be to avoid the expense and disruption of re-locating the mains head.

Any thoughts peeps?

Thanks.

 

[Guest123]

Cant really see an issue mate.....is it possible to run an armoured or split con???

You may need some mechanical protection where the cables travel under floors if they are to be drilled though joists.

Switchfuse at supply end into CU will be fine.

 

[acvc]

Yep I'd feel safer were it armoured all the way! Thanks Lenny.

 

[Des 56]

If you were running a twin and earth sub main,likely you would be less concerned
The protection for the tails is double insulation so it is permissable to route them with the same considerations that are given for twin and earth regards mechanical protection etc

I see no problem taking them through floor joists as long as the holes are at permissable depth and spacing,
Older dwellings example prefab units used to have the suppliers tails running the full lenghth of the attic spaces,little has changed other than the Rcd requirement for buried cable to make it less compliant today

 

[acvc]

Thanks for that Des, really helpful.

This thread cross-feeds to another current post by Magic-Sid about a bungalow.

I've still got a question similar to Magic Sid's:

Would all the regs in Sections 4, 5, and 7 about RCD requirement apply to sub-mains as well? The tails will be installed in mostly the same environment as final circuits and certainly feeding final circuits that will e.g. be less than 50mm in walls, outdoor use <32A, locations with bath/shower etc etc etc.

Bit hypothetical, but anyone get my point?