This also means that a person in an installation touching a live part whilst standing on the earth would take the place of the voltmeter in Fig. 16.1a , and could suffer a severe electric shock. Remember that the accepted lethal level of shock current passing through a person is only 50 mA or 1/20 A. The same situation would arise if the person was touching, say, a faulty appliance and a gas or water pipe ( Fig. 16.2 ).