Do UK ring circuits rely on a single breaker at the fusebox? I assumed that they would have a breaker for each leg of the ring (8A + 8A in your example).
That sounds really dangerous as a cut ring would be fused at double the current capacity of the wire. Would the wire in your example be rated at 8A or 16A?
I have little to no knowledge of the UK power setup but have heard that its meant to be pretty safe. What am I missing?
you’re not missing anything, it’s an unhinged tradeoff that you do because you need to conserve copper for brass casings because nazis are in calais, there’s zero reason to do this today. apparently it’s still allowed in uk for some unthinkable reason but i haven’t heard of it anywhere else. yes, single fuse *per ring is used, rated at double what it would be in star/radial circuit
you don’t even need a fault, sufficient asymmetry in ring geometry or load distribution already will cause this problem
60yr old house in the UK, we have one breaker per socket circuit for example. It uses 2.5mm wire which can handle 30A, so that would be the max recommended fuse rating at the breaker. That way it’s still protected if there is a break in the circuit anywhere.
We also have a separate lighting circuit with 1.5mm wire and a lower breaker fuse rating.
It can lead to some annoying fuckery though. I recently updated a ceiling light and was frustrated at why it wouldn’t switch on after triple checking every connection. Had to get out a multimeter and investigate all over the house. Turns out at some point in the past a previous homeowner had not bothered to connect the neutral wire back to the fusebox at an entirely different ceiling light, leaving the neutral floating. It was sitting at 110V rather than zero. Somehow it was OK to do that with old lights.
Do UK ring circuits rely on a single breaker at the fusebox? I assumed that they would have a breaker for each leg of the ring (8A + 8A in your example).
That sounds really dangerous as a cut ring would be fused at double the current capacity of the wire. Would the wire in your example be rated at 8A or 16A?
I have little to no knowledge of the UK power setup but have heard that its meant to be pretty safe. What am I missing?
you’re not missing anything, it’s an unhinged tradeoff that you do because you need to conserve copper for brass casings because nazis are in calais, there’s zero reason to do this today. apparently it’s still allowed in uk for some unthinkable reason but i haven’t heard of it anywhere else. yes, single fuse *per ring is used, rated at double what it would be in star/radial circuit
you don’t even need a fault, sufficient asymmetry in ring geometry or load distribution already will cause this problem
60yr old house in the UK, we have one breaker per socket circuit for example. It uses 2.5mm wire which can handle 30A, so that would be the max recommended fuse rating at the breaker. That way it’s still protected if there is a break in the circuit anywhere.
We also have a separate lighting circuit with 1.5mm wire and a lower breaker fuse rating.
It can lead to some annoying fuckery though. I recently updated a ceiling light and was frustrated at why it wouldn’t switch on after triple checking every connection. Had to get out a multimeter and investigate all over the house. Turns out at some point in the past a previous homeowner had not bothered to connect the neutral wire back to the fusebox at an entirely different ceiling light, leaving the neutral floating. It was sitting at 110V rather than zero. Somehow it was OK to do that with old lights.