What is supplementary equipotential bonding?
This is required in rooms or locations which have an increased shock risk such as rooms containing a bath or shower. Metal parts are connected to the protective conductor of each circuit supplying Class I and II equipment in zones 1-3. This reduces any potential difference between any of these parts during an earth fault condition and reduces the risk of receiving a dangerous electrical shock. Under the 17th Edition (1st July 2008) supplementary equipotential bonding can be omitted if all circuits to the room have RCD protection, main protective bonding is installed and circuits comply with the maximum disconnection times.
