Length of tails...?

[Angelbabes]

What is the maximum length of tails from supply to to consumer unit.

I always believed it was 3m... then I heard, it is up to 30m... then I heard, has to be switched after 3m. then I heard you can get away with 5m.

I cannot seem to find any hard and fast aswer in the regs...

If there is a reg can anybody tell me what it's ref is or at least give me a true answer...

Thanks in advence...

Angelbabes...

 

[Steve]

Actual tails shouldnt be much longer than a metre IMO.

Any longer, they should be switched and run in SWA.

 

[securespark]

What the DNO are happy with depends on which DNO it is: they all seem to have different rules of thumb.

Some 1m, some 2m, some 3m, but rarely over. I personally would not go over 2m without then fusing down and running a submain, preferably of split-con.

 

[ban-all-sheds]

I cannot seem to find any hard and fast aswer in the regs...

Nor will you. From the POV of BS7671 they are just DI singles, so there are no special length restrictions, just the regular ones of adjusted CCC, OPD value and characteristics, voltage drop, suitability for whatever external influences there are etc etc etc.