arvesti, mille kaitset elektrilöögi eest ei usaldata ainult põhiisolatsioonile, vaid sisaldab lisaks puudutatavate juhtivate osade ühendusi paigaldise kohtkindla juhistiku kaitsemaadusjuhiga sellisel moel, et puudutatavad juhtivad osad ei pingestu põhiisolatsiooni rikke olukorras, meter in which protection against electric shock does not rely on basic insulation only but which includes an additional safety precaution in that accessible conductive parts are connected to the protective earthing conductor in the fixed wiring on the installation in such a way that accessible conductive parts cannot become live in the event of a failure of the basic insulation