Safety requirements for electrical installations in bath and shower rooms are defined in DIN VDE 0100-701:2008-10. They are based on IEC 60364-7-701:2006 (CENELEC harmonisation document HD 60364-7-701:2007).
Rooms with bathtubs and showers
In rooms with bath tubs or showers, a fault-current protection device (FI switch, RCD – residual current protective device) with a maximum operating current of 30 mA is mandatory. The conductive components of fresh and waste water supply as well as heating, air conditioning and gas supply must be factored into the additional potential equalisation.