In earth-free locations, the appearance of dangerous touch voltages is prevented by means of local equipotential bonding conductors. In the case of failure of the basic insulation, in fact, such conductors, by connecting together both simultaneously accessible Class I equipment supplied by different phase conductors and the floor (if conductive), can prevent, or reduce, the appearance of dangerous potential difference in the installation being protected. The equipotential bonding, in fact, makes the location a Faraday cage, which becomes equipotentially energized upon faults (Fig. 2.13).