just thought of another one.
went to a property to assist in a kitchen rip out and remove some socket prior to builders taking a wall out.
when i arrived wall is still up, and most of kitchen still fitted, so i make a start
first off, turn the socket circuit mcb off in the 16th ed board, went back in and checked with socket and see, woah its still live, lucky i checked
so i went back outside and turned off the other socket mcb, back in to check, and still live? im confused now.
daughter was in the shower so i couldnt go any further at that point, so assisted in ripping out the kitchen, and found this
ok looks knackered but its being replaced anyway.
daughters out of the shower so i went back out and turned off the rcd for the protected side,(actually it was already off) back in and its still showing live
so back out again, turned everything off, took cover off the board and there it was..............
at some point, someone had rcd nuisance tripping so they had the bright idea of linking out the rcd (not sorting the fault) only the muppet only did the live, and left the neutral, yet it had still worked????
put the links back as it should of been, left power off and went back to doing what i was there for.
started at that knackered socket from earlier, OMFG
there was a neutral earth fault.........................................
suddenly it was all clear, the reason everything worked was because it was running live to earth, back feeding down the cpc of the kitchen ring
but hold on, the shower and cooker were also on the rcd??????
yep 2 ring mains, cooker, and shower were all running down the neutral earth fault in that socket, and had been for about 2 years. amazingly the cpc survived intact, and ring tested ok