Discussion in 'Electricians' Talk' started by Andy Neillans, Sep 3, 2018.
I would also be looking at Henley block, and a MCB/RBCO/RCD what ever just for vehicle charging, not connected to main CU with what you describe. The idea of taking power 30 meters there and back with volt drop involved does not make much sense.
However I know when my son rewired his house he wanted the supply point changing, he fitted the new CU near to where the new DNO head would go, it included a new outside box for meter. However before complete this also resulted in long tails between boxes.
I wonder if some thing similar has gone on? He ended up with long cables from DNO head to new CU for a long time, it seems who ever brought power into the houses cheated and used one cable to feed two houses, which while they were council houses was not a problem, but as the houses were sold it resulted in power cables being clipped to wall of house without a way leave.
The DNO records showed individual feeds, but that was not the case. So although the moving of the DNO head was agreed before the CU was re-located, it became a problem, specially as an extension planned was going on the wall where the cables went to supply next door.
I can see that some thing like this could result in long cable runs remaining. Specially if the house changed hands before all completed. If this is the case, then maybe there is a reason for taking supply from the existing CU, but can't see why from what you have said?
Cable sizes are the cross sectional area, not the diameter. I think you are measuring the width of the cables from what you are describing ie 10mm and 8mm, those are not cable sizes. Likely you will have 16mm2 meter tails if you previously had a 40A main fuse. With a 100A main fuse you must have 25mm2 meter tails so get your electrician to advise you.
Although, as it’s a fused submain to the main CU with its own (likely 63amp) fuse, 16mm tails are fine.
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