- In another bedroom, I had to chisel out the ring main cable from a
concrete wall. This involved accidentally baring the cable in parts so I
decided to cut it off from the highest point I could and apply new
cable. To
join old + new cable, I used 30 amp terminal blocks but over tightened
some
so the metal cracked. The cables seemed to be fixed tight so I didn't
worry.
Should I have?

If you are going to plaster over the cable again then you need to either
solder or crimp the join and not use screw terminals. Sheath the
individual wires and the overall cable in heatshrink as well.


OK - I've decided that the terminal blocks aren't a good enough solution so
I've decided they must come out. Some were contained behind plasterboard,
which has meant a messy pain in the a*** to expose them, but I guess you
live and learn.

I'm going to go and buy a crimping kit but I don't fancy mucking around with
heatshrink wrap (I haven't got a soldering iron and the terminal blocks I'm
replacing are in awkward positions). Will good electrical tape do as good a
job?

One other question - is there any harm in my using 4mm core cable in what
may be a 2.5mm core radial system?