‘WIRED FOR SUCCESS’
It’s time to dive into the electrifying unknown with our new column featuring Reuben Clark, the wizard of wires in pool service! Reuben is here to illuminate the path to a safer, more efficient, and expertly-wired outdoor oasis.
Reuben Clark has been the President and cofounder of Consolidated Manufacturing International, LLC (CMI) for more than 22 years, developing and manufacturing electrical products for the pool industry. Reuben holds an MBA, is a member of the IAEA, NCEIA, and NFPA, and has been involved in development of the National Electrical Code. He lives in Raleigh, North Carolina with his wife and has three grown children.
Let Reuben’s expertise shed light on everything electrical from the complexities of bonding and grounding to electrical code compliance and troubleshooting issues.
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Today’s Topic: Water Bonding:
A local licensed electrical contractor who mainly wires pools recently asked me if the water in a concrete, plastered pool needed to have an intentional water bond if there was no metal in contact with the water, such as ladder or handrail. He was concerned that the plaster finish would render the concrete shell nonconductive by creating an insulating barrier between the water and earth. He feels the pricing pressures of competition to reduce costs but will not sacrifice safety for money, and he therefore asked our state electrical inspector for a determination.
The inspector recited parts of Article 680.26(B) & (C) of the National Electrical Code, basically stating that if the pool shell meets the requirements of 680(B)(1), then it is a bonded part. Clarifying, he holds the position that if a concrete pool shell has uninsulated steel rebar, and the contractor installs cast-in-place concrete, pneumatically applied or sprayed concrete, and concrete block with painted or plaster coatings, it shall be considered conductive, and no additional bonding of the water is required.
I have worked with NEETRAC (National Electric Energy Testing, Research and Applications Center) on a couple of projects, and when one of their lead engineers told me in 2007 that he was defending his proposal at a Code Making Panel meeting requiring “bonding of the pool water,” I thought it was absurd. You can’t bond dirt; you can’t bond concrete; but to my surprise, you can indeed bond water.
Apparently, some mild shock events occurred on pools, so the testing lab demonstrated that a pump motor could generate a static charge buildup on the pool water in vinyl liner or fiberglass pools if it was well insulated from the earth. Think of rubbing your socks or a balloon on the carpet. In recent years, metal ladders, handrails, and light rings have not been present on many pools or have become nonmetallic, and therefore, the water circulates in its own environment and is not in contact with the earth to dissipate the charge or there is no path for which it can bleed off the static charge. Therefore, Article 680.26(C) of the National Electrical Code required the pool water to be in direct contact with at least 9 square inches of approved non-corrosive metallic surface and bonded to the pool’s equipotential bonding system, when no other metal objects defined in Article 680.26(B) are in direct contact with the water.
While asking several experts in this area, many initially felt it was better to take that extra step for safety. But after further thought, most decided that because plaster suppliers do not make a claim for conductivity and most plasters are made largely of (conductive) cement, they see no need to contradict the sentiment found in the NEC. A colleague at a prestigious research lab agreed. He also stated that this static charge, which is addressed by water bonding, should NOT be confused with stray voltage, as they are two different animals. I have not seen any reports of physical damage caused to a person by this static charge. Yet there are many reports of physical harm and even fatalities caused by stray voltage on pools and decks. Protection from stray and contact voltage is essential and accomplished by proper bonding of the pool system and its metallic parts by creating equipotential planes. This safety requirement was further enhanced by a TIA 23-9 to the 2023 Edition of the NEC . Always ask your local Authority Having Jurisdiction (AHJ) regarding safety and building codes prior to working on pools, decks, and pool equipment. Also, if you are not licensed to perform electrical work, hire someone who is. In this case, it seems the electrical contractor will not have to include a water bond on plastered concrete pools, as his state’s AHJ has weighed in on the issue, because the electrician took the proper step and asked.
