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Help Please!

Question. When he comes back.

If he can't find the break and turns it into two radials. Can you talk me through the process?

This is all new to me so I'm just assuming. This problem has got me really curious and I'm trying to use it as an opportunity to understand and expand my understanding.

So I've got some very basic questions and assumptions.

1. As an electrician. How would you tell for sure a circuit is a ring or radial?

2. Once you determine it's a ring and discover there is a break. How do you narrow it down to discover where exactly the break is ?

Especially on an old house where the sequence the sockets run could be random , various spurs e.t.c.

3. Say you find a the break between two sockets but can't fix / replace the cable and decide to turn it into two radials.


What do you do ?

Disconnect the broken length cable at BOTH sockets between the break. So you don't end up with a cut wire that's still getting power, in a hidden location behind some wall or under floorboards?

Just trying to understand. Please remember my knowledge is extremely limited and experience is near on zero.


I'm asking party because I'm curious and partly I want to understand, so I can understand what the electrician will be doing and will be able to know if he's doing a proper and safe job.
 
its all very simple if the electrician is good and has the equipment , which they should have a Multi-Function Tester (MFT)


in the CU he just replaces or uses if available the 32A for a 20A and then uses another 20A MCB
so in the current 32A you have two wires which form the ring as i showed links to the images in previous post





so now 1 goes into the replacement 32A - 20A mcb and the other goes to a new or existing 20A unused MCB
as i said my daughter had that done - very easiy

you can easily measure a ring - an electrician will have a box that checks - I'll try and fins a link - otherwise you just take the 2 wires out the mcb , 2 wires for earht and 2 wires for neutral and test with a multimeter continuity test
he should also do an insulation resistance test,


My daughters electrician as i was there , tested every socket they could find, hoping to see a a disconnet and alsomeasured the resistance at that socket and in fact put label with that figure on each socket , as i say she could not find the break (suspected where it might be - but that meant lifting all the flooring to find exactly ) and so made 2 radials, as mentioned , I also got her at the same time to run a ring into the kitchen as she was having a new kitchen in some future dste , with 3 double sockets on one side of the kithcen - it was very easy and as i was there , we purchased the cable and I ran the cables into the kitchen leaving a lot of wire under the plinth
 
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1. As an electrician. How would you tell for sure a circuit is a ring or radial?

In the case of a ring, the L+N+E begin at the consumer unit, MCB, go to every socket on the ring, then back to the same MCB. That's why it's called a ring, a full circle, out, and back. So their should be two reds (or browns), connected to the MCB. A basic check, to check that the ring has not been broken, is to take out those two wires, and check if there is continuity between them. You would also check the N and the E, for continuity.... No continuity, indicates a break in the ring somewhere.
 
In the case of a ring, the L+N+E begin at the consumer unit, MCB, go to every socket on the ring, then back to the same MCB. That's why it's called a ring, a full circle, out, and back. So their should be two reds (or browns), connected to the MCB. A basic check, to check that the ring has not been broken, is to take out those two wires, and check if there is continuity between them. You would also check the N and the E, for continuity.... No continuity, indicates a break in the ring somewhere.
Yes, but only IF it IS a ring.

A radial could have two browns (or reds) originating from the MCB Hence if there are two conductors at the MCB and testing shows no continuity between them that indicates that there is a broken ring OR that is is a radial circuit. With no other information, one could not tell which of those possibilities was the case.
 
You do have conductor size and MCB rating. Conductors will likely be 2.5 or 4 mm2, MCB 16, 20, or 32 A. 16 or 20 indicate a radial, 2.5 mm2 and 32 A a ring, 32 A and 4 mm2 a radial. If you have 2.5 mm2, 32 A and no continuity on only one or two conductors, it’s likely a broken ring, if there’s no continuity on any conductor it’s probably an incorrectly installed radial circuit.
 
A radial could have two browns (or reds) originating from the MCB Hence if there are two conductors at the MCB and testing shows no continuity between them that indicates that there is a broken ring OR that is is a radial circuit. With no other information, one could not tell which of those possibilities was the case.

True, which why my ring circuits, are clearly identified as ring circuits, in the labelling - as well as having a 32amp MCB.
 

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