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sparky351355
i recentley carried out an ecr to a domestic dwelling and found the main earth was sparking when touched to the earth bar, all test result were ok , all ir's to all ccts were +299Mohm , main protective bonding conductors all verified , split board installed (16th) split with 30 mA additional protection and rcbos for lights. TNC-s earthing system. basically no problems, however i seem to be getting 72v from the earth bar to the main earth at the consumer unit. this voltage decreases as i start to turn off each cct all the way down to 0v, ive had the supply checked by DNO all ok. im using a megger mft 1720 test kit , totally bemused by what is happening,> im just wondering wether this is an induced voltage but from where ? any suggestion would be greatly welcome , many thanks.