A 'consumers meter tails' question.

[Ashnook]

I am doing a new build and want to locate the suppliers cut-out and meter in the garage but have the consumer unit in the house. The distance from the Meter to the Consumer Unit (CU) is about 15M.

What I want to do is install a breaker on my side of the meter in the garage and run an armoured cable underground to the house and consumer unit. Is this permissible.

There is no indication in the On-site Guide although it does show the possibility of a main switch between the meter and the CU. I have also heard that there is a limit of 5M on 'tails' but again the On-site Guide does not mention this.

Thanks, Brian

[Bob Mannix]

Well, inside a building, it's called a submain and has to be approrpiately rated (eg 25mm^2 for 100A supply). It also has to be overload protected at the meter end, ie not just a breaker but an overcurrent device at 100A (for example). In your case it sounds as though the garage is separate so more rules may apply - in particular earthing arrangements. The usual limit for meter tails is 3m but this may differ around the country.

[Ashnook]

Thanks Bob, I am happy to comply with any over current/breaker and earthing requirements, as well as cable size.

[John Rumm]

Yup, in fact over a certain length of tail (which varies with supplier) you need a switch fuse isolator at the start of the cable run to the CU.

[Ashnook.]

Thanks John, that's what I will plan to do then.