I have a customer who lives in a grand old house which suffers from damp.
The ground floor sockets (2 different circuits) IR test at around 0.3Mohms L/N-E. This was actually 0.01Mohms but I have already done some fault finding and managed to improve it.
Most of the back boxes are very rusted and flaking to bits with moisture inside them. As stated, I have done some improvements to the sockets and boxes but this has only managed to get the IR up to 0.3Mohms (L/N-E). I have looked thoroughly for any more sockets/FCU's that I may have missed but I now feel the remaining fault(s) are within the walls, even though this doesn't make sense as I can't see how moisture would have got inside the cable (Its black/red metric PVC).
I think the existing cables have metal capping within the damp walls, but again, even if this capping is rusting I cant see how it will affect the PVC covered cable. The wiring is approx 25 years old
My questions are..
1. What can you do about damp? It's pointless to rewire as the damp problem will still be there. Are there ways to protect the boxes and sockets from damp?
2. What are the solutions if I cannot raise the IR above 0.3Mohms? I'm guessing I have to map out the entire circuit, and find every single fault, but then what? It's an immaculate house, surface trunking not an option, new cable in wall not really an option as existing damp problem already somehow affecting cables in walls (unless some kind of cable joints in walls which are affected).
3. Are these designed to be installed in the wall? 2 Gang 35mm PVC Flush Box Round Corners with 20mm Conduit KO White (Sold in 1's) - https://www.cef.co.uk/catalogue/products/1063228-2-gang-35mm-pvc-flush-pattress-box-round-corners-with-20mm-conduit-ko-white
Usually fault finding is easy. 1 fault, bit of IR testing, fix fault. In this case there are faults everywhere and not just in the actual sockets!
The ground floor sockets (2 different circuits) IR test at around 0.3Mohms L/N-E. This was actually 0.01Mohms but I have already done some fault finding and managed to improve it.
Most of the back boxes are very rusted and flaking to bits with moisture inside them. As stated, I have done some improvements to the sockets and boxes but this has only managed to get the IR up to 0.3Mohms (L/N-E). I have looked thoroughly for any more sockets/FCU's that I may have missed but I now feel the remaining fault(s) are within the walls, even though this doesn't make sense as I can't see how moisture would have got inside the cable (Its black/red metric PVC).
I think the existing cables have metal capping within the damp walls, but again, even if this capping is rusting I cant see how it will affect the PVC covered cable. The wiring is approx 25 years old
My questions are..
1. What can you do about damp? It's pointless to rewire as the damp problem will still be there. Are there ways to protect the boxes and sockets from damp?
2. What are the solutions if I cannot raise the IR above 0.3Mohms? I'm guessing I have to map out the entire circuit, and find every single fault, but then what? It's an immaculate house, surface trunking not an option, new cable in wall not really an option as existing damp problem already somehow affecting cables in walls (unless some kind of cable joints in walls which are affected).
3. Are these designed to be installed in the wall? 2 Gang 35mm PVC Flush Box Round Corners with 20mm Conduit KO White (Sold in 1's) - https://www.cef.co.uk/catalogue/products/1063228-2-gang-35mm-pvc-flush-pattress-box-round-corners-with-20mm-conduit-ko-white
Usually fault finding is easy. 1 fault, bit of IR testing, fix fault. In this case there are faults everywhere and not just in the actual sockets!
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