electricity to garage

[Fred]

Hello,

Our garage has a socket which seems to be a 2.5mm T&E spur from the ring main. I'd like to have it brought into the 21st century. I understand that the best way to do it is to have say a 40A mcb that runs "big" T&E to the garage; then in the garage have another CU with

2 MCBs: one for sockets and one for lights. Is this right?

I understand that I need to have a voltage drop of less than 9v. Should the T&E be 4mm or 6mm? (Garage is attached to house so no burial of cable required).

I assume that part P prevents a DIY install?

Thanks.

[John Rumm]

Answers to these types of questions can get a bit deep, so in case you have not seen it here is some background:

Our garage has a socket which seems to be a 2.5mm T&E spur from the

Yup that is one way of doing it.

You need to think about RCD protection and where you want it. You also need to look carefully at earthing - what type you have in the house, and what would be best in the garage.

That depends on the design load, and the length of the cable run - the voltage drop will be in proportion with it. Have a look at the submain design section of the wiki article above.

No, part P does not prevent DIYing anything. It may require a building notice submission though if the work is not classed as "non notifiable".

[David Hansen]

On Wed, 05 Dec 2007 15:13:31 GMT someone who may be Fred wrote this:-

Does it have any lights in it?

Pretty much. The type of cable used may be one of many, but appropriately installed T&E is usually fine.

That depends on the distance and other factors. As well as voltage drop there is the question of having an adequate disconnection time. The cable size may need to be larger then that necessary for voltage drop reasons, in order to cope properly with faults.

According to the Labour Party that nonsense does not prevent DIY, however you should officially get a bod from the council to inspect it or arrange for it to be inspected.