I have recently had some electrical work in a new extension inspected, the work was given the OK but the inspecting electrician has noted that the main earth to the CU ( supplied by the local electrical authority 25 years ago when the house was built ) is only 6mm, as opposed to the present requirement of 16mm as per rev 17 . He is reluctant to sign the certificate of inspection because of this . Can any one help/advise/comment please ?
