(A) Performance. Bonding as required by this section is intended to help reduce or eliminate voltage gradients in the pool area by forming a common bonding grid. Bonding is not required to provide a low-impedance ground-fault current path.
FPN: The bonding requirements contained in this section are not intended to require an 8 AWG copper conductor to be bonded to a panelboard, service equipment or electrode.
(B) Bonded Parts. The following parts of a pool, outdoor spa or hot tub shall be bonded to a common bonding grid of the type specified in 680.26(C).
(1) Metallic Parts of Structure. All metallic parts of the water structure, including the reinforcing metal of the pool shell, coping stones, and deck, shall be bonded to a common bonding grid [680.26(C)]. Steel tie-wires made up tight are suitable for bonding reinforcing steel together. Figure 680-19 un680-19 680-26B1 01.cdr
(2) Underwater Lighting. Metal forming shell used to contain underwater pool, outdoor spa, and hot tub luminaires and speakers.
(3) Metal Fittings. Metal fittings within or attached to the pool, outdoor spa or hot tub structure, such as ladders and handrails.
(4) Electrical Equipment. Metal parts of electric equipment associated with the pool, outdoor spa and hot tub water circulating system, such as water heaters and pump motors.
Where a double-insulated water-pump motor is installed, a solid 8 AWG copper conductor shall be provided from the bonding grid to an accessible point in the motor vicinity.
(5) Metal Wiring Methods and Equipment. Metal piping, fixed metal parts, observation stands, towers, platforms, or diving structures, as well as metallic surfaces of electrical equipment located within 5 ft horizontally of the inside walls of the pool, outdoor spa or hot tub, and within 12 ft above the maximum water level.
Author's Comment: Bonding is required for diving structures, sliding glass door frames, windows, fences, screen enclosures, heater equipment, and the metal cases of electrical equipment, such as the blower, chlorinator, etc. located within 5 ft of the water’s edge.
(C) Common Bonding Grid. The metallic parts of a pool, outdoor spa or hot tub specified in 680.26(B) shall be electrically bonded to a common bonding grid by a solid conductor not smaller than 8 AWG. The termination of the bonding conductor shall be made by exothermic welding, or clamps labeled (listed) as being suitable for the purpose. The common bonding grid can consist of any of the following: Figure 680-20 un680-20 680-26C.cdr
(1) The structural reinforcing steel of the concrete pool, outdoor spa or hot tub that is secured by steel tie-wires.
(2) The wall of a bolted or welded metal pool.
(3) A solid copper conductor, insulated, covered or bare, not smaller than 8 AWG