This is a follow-up to the CU replacement job (parents house) with a massive earth which I posted a query about in the summer. Thanks for all the help.
The last job is to replace the feed from the switch fuse to the new
100/80A split load Contactum CU (which replaced the old fuse box).The old rubber covered cable (imperial roughly = 25mmsq) crosses the house (about 9m) from the 60A switch fuse (near the incoming supply) to the new CU. It is enclosed in a metal conduit, but looks dodgy & tends to crumble if handled.
Can this be replaced with standard 25mmsq sheathed tails? IEE regs give 114A rating for this cable & sFAIU table 4B1, as a pair would be only 1 circuit, they could be run touching each other clipped to the side of the floor joists without derating. Using 100A cable for this gives me the option to replace the fuse box with a 100A one.
BTW the 10mmsq earth cable to the CU recommended here in the summer is already in place.
It looks the simplest method to me, but are there any snags, or is some other cable preferred?
thanks for all the help so far - the end is almost in sight & all I wanted was to visit & not have to scrape about for socket converters!