Really I need to get back onto National grid who are the DNO, but for now there’s no issue. As it’s an older house, the main wire in he said is much thicker than newer ones. I am considering getting maybe just batteries and not solar panels, as we live in a 3-story townhouse built in the 1920s. Which I can charge overnight when not charging the car, and run most of the daytime energy off those. We average about 7.5kw a day during peak times. Again, I have no real clue as to what or the costs to have it done, obviously as cheaply as possible.
National Grid (Western Power, as I still refer to them) are very good, it worth getting back intouch with them to fit an 80A fuse. Hopefully you will get a different contractor or gang
If the three cables are the same size, it could be two neighbours are looped from the main supply in your house. Whils’t its not common, its also not unheard of.