Main protective bonding

Also known as Main bonding, Main earth bonding

Main protective bonding connects incoming metal services or other extraneous conductive parts to the main earthing terminal so touch voltages are reduced during a fault.

Main protective bonding connects incoming metal services or other extraneous conductive parts, meaning metalwork that can introduce an outside electrical potential into the installation, to the main earthing terminal with main protective bonding conductors. In home energy work it is a fixed electrical-installation term that may appear in certificates, condition reports, Part P information, EV chargepoint checks and handover documents for solar, battery or heat-pump work. It is related to equipotential bonding, but it normally refers to the main bonding conductors for services such as water, gas, oil or structural steel rather than supplementary bonding inside a room.