Our very elderly neighbour has recently started having irregular RCD tripping on her ring mains ccts. Usually with a few days in-between. There are two (Steeple) MCBs in the fuse box with their circuits supplied through the RCD. She had her side utility room rebuilt and new LED lights fitted recently. These are supplied by a 2-pole switched fused spur on one ring. I changed the sfs for her at the weekend as the old one was buzzing a bit… As both live and neutral are switched in the box and the lights are off when a trip happens I have discounted this new wiring. Nothing else has changed electrically.
I spent many years on the installation and testing of DC, control and RF wiring but have no real experience of testing domestic ac mains wiring. My question is, if I knock the main breaker off and completely isolate the two ring main circuits in the fuse box by disconnecting the lives from the two MCBs and their neutrals from the bar is a DC resistance test of lives and neutrals to earth going to show me anything useful which would help identify the cct with the potential high leakage? Or does it need some sort of an ac resistance test using a higher voltage?
Thanks.
I spent many years on the installation and testing of DC, control and RF wiring but have no real experience of testing domestic ac mains wiring. My question is, if I knock the main breaker off and completely isolate the two ring main circuits in the fuse box by disconnecting the lives from the two MCBs and their neutrals from the bar is a DC resistance test of lives and neutrals to earth going to show me anything useful which would help identify the cct with the potential high leakage? Or does it need some sort of an ac resistance test using a higher voltage?
Thanks.