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EICR code for ring within a ring

Doing an EICR at the moment and fairly sure I have found a ring within a ring, how would you code it?

Protective device 32A MCB and upstream 30mA RCD.

Shortest ring R1+R2 0.17

Longer ring R1+R2  0.54

r1 0.70

r2 0.87

rn 0.72

The short ring has most of the load as it covers the kitchen and fused spur to garage, the longer section is a couple of bedrooms and hallway

Above results to not include fused spur to garage R1+R2 1.10.

Normally I would put a 20A breaker in and code as a C3 but given the loads on the circuit not sure if in this sittuation I would end up with nuisance tripping. 

Appreciate your thoughts

Thanks

Parents
  • when you say ring within a ring, I may not have the right picture -

    do you mean figure of 8  with  4 wires meeting at some point to make a waist ?

    Or a sort of circle with a double track section almost as if we had 2 spurs from different parts of the ring  that joined up ?

    Are there

    just 2 ends at the CU not 4 ?

    All sockets 'mid ring' not spurs ?

    But ring-round resistance different from different sockets ?

    Either would be unusual, and quite likely a  mistake. Certainly not in the OSG or other lists of pre-packaged circuits that require no design effort, but  neither is very likely to be dangerous at 32A if all cable is 2.5mm, all sockets are fed from two cables,  and these are well made off.

    Problem is how to be sure ? 

    As you say a 20A MCB is one dead cert way not to overload a cable, and a common fixall for the ring that has been crab clawed into a centre fed radial, but you probably do not need to. Is the cable showing signs of distress anywhere ?  If not could well be c3 with the breaker left alone.

    Also, if badger has been at it how confident are you it is indeed the right sort of cable and there are no funny joints anywhere hidden.

    Mike.

    'badger'  being a reference to being  rough as a... not entirely PC link.. 

Reply
  • when you say ring within a ring, I may not have the right picture -

    do you mean figure of 8  with  4 wires meeting at some point to make a waist ?

    Or a sort of circle with a double track section almost as if we had 2 spurs from different parts of the ring  that joined up ?

    Are there

    just 2 ends at the CU not 4 ?

    All sockets 'mid ring' not spurs ?

    But ring-round resistance different from different sockets ?

    Either would be unusual, and quite likely a  mistake. Certainly not in the OSG or other lists of pre-packaged circuits that require no design effort, but  neither is very likely to be dangerous at 32A if all cable is 2.5mm, all sockets are fed from two cables,  and these are well made off.

    Problem is how to be sure ? 

    As you say a 20A MCB is one dead cert way not to overload a cable, and a common fixall for the ring that has been crab clawed into a centre fed radial, but you probably do not need to. Is the cable showing signs of distress anywhere ?  If not could well be c3 with the breaker left alone.

    Also, if badger has been at it how confident are you it is indeed the right sort of cable and there are no funny joints anywhere hidden.

    Mike.

    'badger'  being a reference to being  rough as a... not entirely PC link.. 

Children
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