Can I ask your opinion in relation to neutral /earth on this rather untidy changeover arrangement located just downstream of the main isolator? There are 2no 3-pole contractors with mains in bottom left and generator in bottom right. On the stud adjacent they have connected gen neutral, DNO neutral and installation earth. The arrangement means a self-imposed conversion to an unauthorised TNCS. I can’t be sure if the existing supply is already TNCS.
Andy, in the ROI we use TNCS almost entirely. Each installation will also have an electrode. The conductor that is referred to as the earthing conductor in U.K. is referred to as the main protective conductor or neutralising conductor in ROI. The earthing conductor is the one that goes from the MET to the earth electrode. Normally in domestic premises the DSO will have the N/E connection sealed and no further neutralising should be made. Sometimes in larger installs the NE link would be made in the main panel. In any event, it is the registered contractors responsibility to ensure that neutralising has been done. However, the photo in my OP is an installation in NI which is presently in the U.K.! Had it been in ROI, it might have been regarded as Ok providing the genny had an independent electrode. It is most likely a TNCS system but I can’t be absolutely certain as the PE readings are slightly different to PN. I am in the process of checking this out with NIE.
Andy, in the ROI we use TNCS almost entirely. Each installation will also have an electrode. The conductor that is referred to as the earthing conductor in U.K. is referred to as the main protective conductor or neutralising conductor in ROI. The earthing conductor is the one that goes from the MET to the earth electrode. Normally in domestic premises the DSO will have the N/E connection sealed and no further neutralising should be made. Sometimes in larger installs the NE link would be made in the main panel. In any event, it is the registered contractors responsibility to ensure that neutralising has been done. However, the photo in my OP is an installation in NI which is presently in the U.K.! Had it been in ROI, it might have been regarded as Ok providing the genny had an independent electrode. It is most likely a TNCS system but I can’t be absolutely certain as the PE readings are slightly different to PN. I am in the process of checking this out with NIE.
