electrical spur

[agamad]

Can anybody tell me what the minimum cable size for a spur is and what is the rating of the protection device at the consumer unit?

[The Builder]

is it a spur from a 32 amp final ring circuit?

[buildersmate]

In other words, is it a spur off the 13A ring main of sockets.
If it is, the cable used is the same as the ring main - 2.5 mm squared conductor T&E.

[agamad]

No, its direct from the consumer unit.

[agamad]

...and how many sockets can be safety supplied by the spur?

[The Builder]

That's not a spur Agamad................ that's a radial cicuit ............ what do you want to use it for?

[buildersmate]

............. and I'm afraid to disappoint you, but you can't (legally) add extra circuits (ring or radial) off the CU unless you are a registered electrician or you make a separate Building Regs application (about £120) to have someone check what you've done afterwards.
You can add a spur yourself, provided you know what you are doing - unless it's in the kitchen.

[agamad]

A friend of a friend (honest!) wants to make use of defunct storage rad circuits. I think he intends to put a couple of double sockets on the end of it. I dont know what the current condutor size is or the fuse rating in the CU. Just looking for the minimum spec.

[buildersmate]

Depends on the size of the cable running to the storage rads.
It will either be 2.5mm square area or 4mm square area (2.5mm square is the size of a normal ring main cable).
If he's got a radial circuit and he's got 2.5mm cable, protect each circuit with a 16A MCB and fit one double socket on the end of each.
If he's got 4mm square cable and a radial circuit, still protect with a 16A and put one double socket on the end - because one isn't allowed more than one double on a spur. The cabling size of 4mm would cope with up to 32A load, but there's no point upping the breaker size.

[agamad]

Thanks BM.