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Site fabricated wooden trunking/capping
Former Community Member
Saw this in a wooden summerhouse, the owner has created his own wooden capping to conceal the cables of a ring final circuit. I was wondering if this might create a safe zone issue where it runs along the bottom edge of the room. The cable is obviously not "buried in a wall at a depth < 50mm but could somebody inadvertently screw something to it. Is it concealed wiring or wooden trunking? Would it get a code if doing a EICR?
And to add a historic note - a few years ago (OK probably rather a lot of years now, but still that I can remember) there was no special table for T&E cable - everyone just used what's now 4D2A.
Then came new buildings with lots of thermal insulation in the walls, and someone pointed out that using 2.5mm2 for rings didn't comply with the then 0.67x rule with a 32A MCB - although many people had continued to used 2.5mm2 as normal and experience suggested there wasn't a problem in practice. So a bit of research later it was shown that the flat shape of T&E allowed better heat dissipation and so the ratings could be increased somewhat. It still didn't quite meet the 21.44A needed for the 0.67x rule though, so the requirement was changed to a flat 20A for a 30A or 32A ring instead.
And to add a historic note - a few years ago (OK probably rather a lot of years now, but still that I can remember) there was no special table for T&E cable - everyone just used what's now 4D2A.
Then came new buildings with lots of thermal insulation in the walls, and someone pointed out that using 2.5mm2 for rings didn't comply with the then 0.67x rule with a 32A MCB - although many people had continued to used 2.5mm2 as normal and experience suggested there wasn't a problem in practice. So a bit of research later it was shown that the flat shape of T&E allowed better heat dissipation and so the ratings could be increased somewhat. It still didn't quite meet the 21.44A needed for the 0.67x rule though, so the requirement was changed to a flat 20A for a 30A or 32A ring instead.
