Meter tails

[Hugh]

Do electrical regulations allow for the use of twin and earth cable between an isolating switch and fuseboard? About 15 years ago I had an istallation and which appears thoroughly professionally carried out - From meter to isolator - normal tails - From isolator switch to consumer unit - twin core and earth (like cooker cable - 16mm??) If OK, what size cable is appropriate for this normal domestic installation as I want to move the fuseboard (and change to a split load with RCD type) to avoid crossing cellar which is occasionally under water!!

tia Hugh

[John Rumm]

Yup. Quite often done if a submain needs to run for a distance. You could use SWA as well.

16mm would be right for a 60A main fuse.

This is after the main fuse I take it? If so what rating is the supply? (typically 60A or 100A?). Not sure you will find a T&E large enough for a 100A submain.

[OldBill]

[Andrew Gabriel]

Yes. Some wiring accessory products might not handle T&E too well, in particular, getting the cables into separate entry holes without some length being unsheathed, given the T&E sheath is lost when you have to separate the cores.

Also, T&E is _very_ much harder to handle than singles of the same size. I did a run of 16mm² T&E, and getting it to go where you want, particularly in a confined space, is quite difficult. Tape over the cut ends, so when it springs back and swipes you across the face, a piece of sharp copper doesn't slice into your skin.

Also, for this application, the CPC (earth conductor) probably isn't large enough. In 16mm², it's 6mm². I don't know what it is in 25mm², but it might be only 10mm² when you need 16mm².

IME, SWA is more commonly used for such cable runs (but is probably even harder than T&E to route, and has same issues with cable sheath).

Should be 25mm² T&E for a 100A supply, but would have to be surface mounted. ISTR T&E doesn't come any bigger than 25mm².

[Hugh]

Thanks all, I've just had confirmation from a qualified electrician (the one who'll certificate the work) and he endorsed a lot of what you all said, BUT: New installations must have meter tails to the fuseboard or armoured cable, which it must be if the distance is over one metre. But as I'm just moving the meter can use the 16mm twin and earth - BUT must add a 16mm earth cable (as was pointed out the integral one is 6mm), and I'll get the cert.

There's plenty of room to manoeuvre so not a problem bending the cable - I'll use an MK split load 8way fuseboard, and there's plenty of room inside.

Thanks again. Hugh