why do you need a seperate earth to make rcd,s and rcbo's work?
an rcd will actuate at around 22-30 milliamps, either of the phase conductors could come loose and touch exposed metal work which would allow the cpd to work,(connected to cpc or not),..... surely as scotty mentioned its a minute inbalance that would trip them....earth leakage that is. Non rcd/rcbo cpd's would require cpc for sure. Hope i'm not missing the point here
