Pool and outdoor electrics in Playa de San Juan

Playa de San Juan is the beach district of Alicante city, with pools and terrace spas within a few hundred metres of the shoreline.

Salt reaches every connection here, including the ones that were never meant to be seen again.

What salt does to a bonding connection

Equipotential bonding works by continuity: an unbroken low-resistance path between every piece of metal around the pool. Continuity is the whole function. A bonding conductor that is present but no longer continuous provides exactly nothing, and provides it invisibly.

Salt attacks that continuity at the connections rather than along the conductor. Where the bonding is clamped to a ladder anchor, a pump body, a pipework fitting or a reinforcement bar, salt and moisture work into the joint, corrosion products build up between the clamp and the metal, and the resistance of that joint climbs from near zero to effectively open circuit — while the conductor itself still looks perfectly intact.

This is why visual inspection is worth very little here and measurement is worth a great deal. A clamp that looks sound can be electrically disconnected, and the only way to know is to put an instrument across it. On a seafront pool that has never been tested, finding one failed connection is more common than finding none.

What extends its life is specification rather than maintenance: stainless or brass clamps rather than plated steel, connections made above the waterline where the geometry allows, and joints protected rather than left bare. Where we replace bonding on this strip we do it with the assumption that everything will be attacked, because it will be.