What must metal piping systems associated with a fountain be bonded to?

For metal piping systems associated with a fountain, bonding them to the branch circuit supplying the fountain is essential for safety. This requirement helps ensure that any stray currents or fault conditions are safely diverted back to the electrical source, reducing the risk of shock hazards to individuals who may come into contact with the water or metallic components.

Bonding to the branch circuit also helps maintain a low-resistance path for grounding purposes, which is critical in reducing the potential for electrical shock. When the piping is properly bonded to the circuit, it allows for effective operation of overcurrent protection devices, such as circuit breakers, which can sense a fault condition and interrupt the electrical flow, thereby preventing dangerous situations.

Additional options, such as grounding rods, the power supply main, or generator systems, do not provide the same level of effectiveness for bonding in this particular context. They may serve other important functions within the electrical system but are not directly related to the bonding requirements of metal piping associated with fountains as per NEC guidelines.