When water comes in contact with an electrical source such as a defective
submerged luminaire or a pump motor, persons in the pool can be subject to an
electric shock The (NEC) National Electrical Code requires protection from this
shock hazard by maintaining an effective connection between the water itself
and the pool's equipotential bonding grid.
AND WHY DO YOU NEED IT
The requirements issued by the National Electric Code (NEC) that a corrosion-resistant conductive structure with a surface area of at least 9 square inches must be installed in contact with the water and connected to the equipotential bonding grid. This ensures that the pool water and the equipotential bonding grid have the same electrical potential.