Pool & Spa Equipotential Bonding

Equipotential bonding ties together the conductive parts around a permanently installed pool so voltage gradients (and the resulting shock in the water or on the deck) are reduced. The bonding conductor is solid copper not smaller than 8 AWG, and connections must be made with listed clamps or fittings suitable for the location (often stainless or brass in wet and chemically harsh areas). Do not use a stranded jumper or a random screw where 680.26 requires a listed bond.

• Conductive pool shells (gunite, concrete, conductive tiles, and similar) — bonded as 680.26(B)(1) describes for the adopted edition.
• Perimeter surfaces — an equipotential bonding grid or conductor around the pool, commonly an 8 AWG solid copper conductor. In the 2020 NEC this is generally 18–24 in. from the inside wall, 4–6 in. below the subgrade. The 2023 NEC revises how perimeter bonding depth is measured (from finished grade: no deeper than 6 in. under paving, and 4–6 in. under bare earth) and was later the subject of further revision / interim language in some publications. Confirm the exact 680.26(B)(2) text and any TIA or local amendment before you trench.
• Metallic components: forming shells, metal fittings, metal covers, ladders, rails, and similar parts in contact with the pool water or within the scope of 680.26(B).
• Electrical equipment associated with the pool (pump motors, heater, metal equipment enclosures) as 680.26(B) requires — this is in addition to the equipment grounding conductor of the branch circuit.
• Metal wiring methods and fixed metal parts in the area, as the section lists.
• Water bonding: the pool water is bonded, typically through a listed water-bonding fitting (or a corrosion-resistant metal fitting in contact with the water, or another method 680.26(C) recognizes in the adopted edition). A pool with all-plastic fittings and no water bond is a common fail.

• Pool and spa equipment has specific GFCI rules (680.5 and the section for the equipment: pumps 680.21, lights, heaters, etc.). Ordinary “bathroom GFCI” habits are not enough — read the 680 section that applies to the item.
• 2023 680.5 splits protection by voltage: Class A GFCI up to 150 V to ground, and special-purpose GFCI (SPGFCI) above that, up to the voltage the rule allows. 2023 also requires ground-fault protection when a pool pump motor is repaired, not only when it is replaced (680.21). Those are 2023 changes — they do not apply in a 2020-only jurisdiction unless the AHJ says otherwise.
• Storable pools, spas, and hydromassage tubs have their own parts of Article 680 / 421 / 680.40 and are easy to get wrong if you apply the permanent-pool rules (or vice versa).

• Underground wiring near a pool has a minimum distance from the inside wall (680.11 / 680.10 in recent editions) and only certain wiring methods are permitted. 2023 tightened when a run within 5 ft is acceptable (complete system, method listed as suitable).
• Overhead conductor clearances over a pool and around diving structures are in 680.9 (check the edition). Do not run ordinary branch-circuit cables over the water as a convenience.
• Receptacles, switches, and equipment have minimum horizontal distances from the inside wall (commonly 6 ft for receptacles, with required GFCI, and a 5 ft equipment setback in some 2023 spa / fountain rules). Lighting in the water has niche, forming-shell, and low-voltage rules of its own (680.23).
• 2023 680.41(B) adds a 5 ft horizontal setback for spa equipment above the low-voltage contact limit unless a permanent barrier is in between.