More on my replacement of 2 old fuse boxes with new CU. All now planned and kit bought except for earthing.
Situation now: There is an accessible earth block in the enclosure where the main incoming fuse is. From this earth block there is:
1 earth to a standalone shower CB 2 earths to one of the fuse boxes 1 earth to the other fuse box 1 earth connected to the gas pipe adjacent to meter.These existing cables (of various sizes!! ) coming out of the block are secure - but one of the grub type screws has a damaged head - so I want to have minimum cables coming out of it)
There will be: New CU - 1 circuit directly to existing shower CB all other circuits from CU to a junction box and then out to the house. CU mounted on mdf - not varnished!!
Junction box has connectors (one per conductor) mounted on DIN rail. The connectors used for earth conductors are "earthed" to DIN rail.
I was going to mount a new earthing block adjacent to CU on the board with block connected directly to the earthing point on incoming mains enclosure (single cable??).
From this block have:
1 earth to existing shower CB (as is) 1 earth to earthing busbar in CU 1 earth to DIN rail in junction box. 1 earth to gas pipe (as is)Is this OK - or is there a better way to do things? What size earth cable should I use? (I've looked at the various old threads on this subject and I'm still not sure). (I don't know what size the holes in earthblock at incoming mains enclosure are)