Extension of ring final circuit


25 Jan 2019
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United Kingdom
Hi there all,

I have a property and I have noticed the following wiring (please see below) in one of the rooms in the house.

It looks like the ring main has been extended.
A single 2.5mm Twin + Earth cable (in red) is providing power from the consumer unit which feeds a chain of electrical sockets via a junction box which returns back to the junction box.

Every socket has two cables (feed in & feed out). To my understanding given that each socket has two cables (provided continuity is sound) the load would be shared between cables to ensure no one cable is overloaded.

However couldnt the single cable giving power from the consumer unit be overloaded or would that be fine given that the power returns back via the junction box?


  • socket diagram.png
    socket diagram.png
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It depends on the rating of the MCB.

25A or less would be alright. If it is 32A then it is not satisfactory.
Thought so, on a 32a breaker the cable coming from the consumer unit could be overloaded right?
Yes it could be.

Are you sure it is 2.5mm²? Single core conductors? Larger cable has seven-strand conductors.
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Thank you for this.
Yes I am pretty certain it is 2.5mm².

Thanks for the advice.

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