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A comment on Suddenly energy independence feels practical:Europeans building mini solar farms. Parent comment

Re:Suddenly energy independence feels practical:Europeans bu... by mytailorisrich on Friday March 27, 2026 @02:09PM (#47546205)
Not expert but one difference is that in Germany the standard wiring is radial circuits with 16A MCBs while in the UK it's ring wiring with 32A MCBs.

So in the UK we have 2.5mm^2 wires in a ring on a 32A MCBs... Of course a 2.5mm^2 wire is rated ~20A so any issues with the ring (sockets still work since connected from the other branch) can burn the wire before the MCB trips...

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Re:Suddenly energy independence feels practical:Europeans bu... by formerly_proven on Friday March 27, 2026 @02:36PM (#47546544)
The "standard" wiring is 1.5mm² on 16A MCBs which are rated to trip at 1.13-1.45x nominal current (so 18-23 A). So this is already mildly improper because you can pull elevated currents continuously and dramatically shorten the life of the insulation.
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Re:Suddenly energy independence feels practical:Europeans bu... by kevin_thibedeau on Friday March 27, 2026 @09:08PM (#47550461)
The rated ampacity of wire for electrical distribution has a significant margin on it.
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Re:Suddenly energy independence feels practical:Europeans bu... by PaulDavisThe1st on Friday March 27, 2026 @09:12PM (#47550490)
Does anyone know the US equivalent terminology for a "ring final" ?
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Re:Suddenly energy independence feels practical:Europeans bu... by hamdingers on Friday March 27, 2026 @10:06PM (#47550810)
We would call it "a serious code violation." It's prohibited in the NEC and always has been, it's objectively less safe.

From what I understand the UK allowed it because of a severe postwar copper shortage and it persists to this day because it's allowed and a bit cheaper.

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Re:Suddenly energy independence feels practical:Europeans bu... by bell-cot on Saturday March 28, 2026 @04:37AM (#47552738)
> From what I understand the UK allowed it because ...

I'd say "severe post-WWII money shortage". After wartime expansion, the global copper industry could physically meet peacetime demands. But the UK was very close to national bankruptcy. And the Luftwaffe had turned an awful lot of their prewar housing into rubble. So - any cost that could be cut, was.

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