Hi all some advice will be Much appreciated please when filling out a eicr the primary supply conductor would that be the main supply cable coming in to the building or would it be the submain of the board under test in a commercial/industrial installation as going through others eicr and speaking with other engineers I'm getting different information I thought it's best to ask on here as I believe theres many bright sparks on this forum. Some say it is the main supply from dno some say it's the supply to the board you working on eg landlords ccu.