More of Why I hate domestics...

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Another 'just job'...
Customer moved in this year complaining of RCD tripping, this used to be 2 houses built, on a hill that have been made into one but the floors are offset by roughly 4ft and as such there are 6 floors.

2 RF circuits in 7/0.029:
Red numbers 1 to 26 in fuse box in left property with various spurs starting at 100 mostly in 2.5mm².
Blue numbers 30 to 48 in CU in right property with various spurs starting at 100 mostly in 2.5mm².
Fuse box and CU are on the same meter and Henly block.

Green numbers are all in the fairly modern kitchen.
Purple numbers have been added to fitted wardrobes in 2 bedrooms.

My count is 71 devices on what started out as 2 rings and as it was so confusing we eventually disconnected every device to do testing and prove circuit except 34 as its visible but inaccessible behind fitted wardrobe.
upload_2020-1-18_15-13-30.png
 
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I wonder how the person that did the kitchen wiring managed to test it?
 
Sounds dangerous and in desperate need of a complete rewire!
That was our initial thought but every item in the system tested perfectly
We have left it like this:
upload_2020-1-19_0-54-38.png

By dissing the grey cables and adding one wago box under the floor by sockets 2 & 3 we ended up with a 32A ring and a radial and as luck would have it an original cooker point on 7/0.044 had been changed to a DSSO and a 20A yellow fuse and blue holder so we swapped them with the red 30A [editted from 32A].
 
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RCD will trip in the case of being fed from two different sources.
Is that necessarily the case if (as presumably in the case here) each of the interconnections is of both L and N (of essentially identical length)?

In that situation, is it not possible that the load currents (both L & N) would be shared between the two sources, but equally for L & N, so that neither source would see an L-N imbalance?

Kind Regards, John
 
Is that necessarily the case if (as presumably in the case here) each of the interconnections is of both L and N (of essentially identical length)?

In that situation, is it not possible that the load currents (both L & N) would be shared between the two sources, but equally for L & N, so that neither source would see an L-N imbalance?

Kind Regards, John
Of course they should be balanced but I guess it only needs one screw to not quite be tight enough. In practice feeding both sides will generally cause nuisance tripping.
 
Of course they should be balanced but I guess it only needs one screw to not quite be tight enough. In practice feeding both sides will generally cause nuisance tripping.
Sure - that's why I asked "Is that necessarily the case..." (maybe I should have written "Is that necessarily always the case..." to be even clearer). ... my point really was that, unlike the case when there is just an N (or just an L) interconnection between circuits (when an RCD trip is inevitable when any significant currents flows), when there is an L+N interconnection, a trip is not inevitable.

Kind Regards, John
 
Rewireable fuse, or cartridge fuse?
Cartridge fuse, Some of the others have been back in to do a little more work with a view to improving power circuits as decorating is being done.
 

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