Garage power

[Electrapeace]

If I connect 4mm2 armoured from a 32A mcb to a garage 30metres away do I need to sub-fuse box in the garage or can I just use it as a radial circuit?
The garage will have two sockets and fused down lighting.

 

[pc1966]

It might not be needed but personally I would use 3 core. It's only 25p more per meter, so an extra £7.50 for 30 meters, which isn't that bad.

Fair point, no harm in having the extra CPC in it.

 

[Dustydazzler]

I always use 3c

 

[John-SJW]

You do get 1mm for light circuits and it is often used.

I recently saw some new build houses by a developer and all lighting was still in 1.5mm, despite in-built kitchen lights and downlighters all being LED. Old habits....

The one off general builders (those who do it all themselves), will not budge from 1.5mm for lighting, not understanding it, so lean on the side of caution. These guys wire houses as rule of thumb. One 32A ring for upstairs, one for down and one for the heavy appliances in the kitchen with all having FCUs over the worktops. Radials for the ckr and immersion. 25mm meter tails no matter. It works, no calculations needed for them.

Many people around the world have slagged rings, looking at the British as odd for using them - they do have their advantages for sure. The great thing about them is that they are generally foolproof from an installation point, using only rule of thumb. I read that was one of the reasons they were promoted in 1942 when planning for the post war building boom, with millions of men being demobbed needing to pick up skills quickly. Hence why we have 13A fuses in plugs, and restrictions of 13A for spurs, to the bemusement of other nations.
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Do they need 3-core?
Why 50m, I thought the run was 30m?

Just an e.g, of price difference. Not using 3 core is well....

 

[davesparks]

I recall one Dutch guy who said the British oversize cables. He said, with widespread adoption of LED lights you are still installing 1.5mm lighting cable when 1.00mm is more than adequate. Lightly used rings are oversized with a total of 5mm. But the oversizing may compensate, even if ever so slightly, over voltage drop.

A Dutch guy said the British oversize cables, well that's great but what does that have to do with anything? Everyone is entitled to their opinion, that doesn't make their opinion any more valid than anyone else's.

The installation of LED lighting is largely irrelevant, the cable size is based on the nominal current for the circuit. The nominal current of standard lighting circuits hasn't changed.