Sorry if this has been covered before. Went to a job today to wire a heating system and the install requires main bonding. The problem is that I can't get to the main board as its solid floors etc. There is a sub main feeding a db upstairs supplied by a 16mm twin. Can I run my 10mm earths to this sub board
? TNC-S earthing. Please be gentle!!
? TNC-S earthing. Please be gentle!!