⊕
Protective Bonding
Main and supplementary bonding to equalise potentials.
Main bonding
Connect extraneous-conductive-parts (incoming gas, water, oil, structural steel) to the MET. Min 10 mm² copper for PME up to 35 mm² supply neutral (Table 54.8); generally half the earthing conductor size, min 6 mm².
Supplementary
In bathrooms it can be omitted if all circuits have 30 mA RCDs, disconnection times are met and main bonding is in place (701.415.2).
Key regulations
411.3.1.2544.1Table 54.8701.415.2