This is the explanation of stray voltage in brief, everyday terms. Electrical Power Generating Companies (Utilities) distribute the electricity via copper or aluminum wire.  Electricity always returns to the source of supply, either over the utility distribution source or, in cases of faulty or damaged wiring or equipment, if there is no available path, current will return to its source by any means available, including the earth or your body.  It normally travels in the ground, and looks for all paths of least resistance. Water is the least resistant path verses the earth.  Therefore, the electricity will travel through a pond or swimming pool and somewhat “electrify” the water.  A fiberglass or vinyl liner pool is a non-conductive shell, so the electricity cannot go through it and thus the swimmer is protected.  A concrete pool is conductive and will allow the electricity into the pool water. However, because almost all concrete pools are reinforced with steel rebar, an equipotential plane is created (called a Faraday Cage), which will not allow the electricity into the pool, and thus the swimmer is protected.

Pool decks used to be predominantly made from poured concrete with rebar reinforcement.  In recent years, two changes have occurred. The first change is that pavers are being used more frequently.  There is no need for steel reinforcement underneath pavers, as they are individual tiles placed in fine sand. The second change is that fiber reinforced concrete (referred to as fibercrete) is becoming more widely used and most builders believe steel reinforcement is not necessary with this. Therefore, in both cases, no equipotential plane is created underneath the surface area of the deck, so stray voltage can appear on the deck and shock people. Swimming Pool Decks are designed to get wet, and thus there is much less resistance verses dry ground.

In 2005, the National Electrical Code established a solution to this problem.  In the absence of a steel rebar grid (which has to be chaired up and fully encapsulated in concrete), a copper grid will provide more than adequate protection so the person standing on the deck will not get shocked by any stray voltage in the area.  CMI began manufacturing the EquiBond equipotential bonding grid, to allow builders to comply with the NEC and construct a product that will protect the public.  Click on the picture below for info about this product.

Water Bonding

This is the explanation of Water Bonding in brief, everyday terms. In the “old days” pools contained metal handrails and metal ladders, and sometimes metal light niches. Per the electrical code, all metal within 5 feet of the water needs to be bonded together. This brings everything to the same potential voltage.  If there is not voltage differential, there can be no current flow, and thus no one will get shocked.  The current trend in pool design as of the last few years, is a neat and clean look, which means no ladders or handrails, and walk out steps are built in to maintain that clean sightline. Fiberglass and Vinyl Liner Pools would now have the water circulating in its own environment, which means that it can be at a different potential voltage.  Thus when the swimmer is on the deck and dips their foot into the pool, or they are in the pool and place their arms on the deck, an electrical shock can occur.

In 2008, the National Electrical Code established a solution to this problem.  In the absence of a handrail or ladder or metal light niche being in the water, an intentional bond must be made. This is accomplished by placing metal with a minimum of 9 square inches in the water, and then bonding it to the other metal and surrounding environment. CMI began manufacturing WaterBond to allow builders to comply with the NEC and construct a product that will protect the public. Click on the picture below for info about this product.

This product maintains no Listing or Recognition from any NRTL (Nationally Recognized Testing Laboratoy, like UL, ETL, TUV, CSA) because there is no standard to test it against.  This is logical because the entire purpose of this product is to do the job that the ladder or handrail used to do. Obviously, neither of these types of products were ever UL Listed or tested by any lab for that purpose. Some products do have UL Listings, but that is similar to putting a metal toaster in the water and bonding it back to the pool’s electrical system.  It has a listing, but the job it is doing in this case has nothing to do with the purpose.  Contact CMI for documentation explaining NO Listing or Recognition is available for this purpose.

STRAY VOLTAGE Info

Feel a shock/Burn/Tingle while standing on the pool deck?  CMI’s EquiBond protects the deck from stray voltage

Click the EquiBond picture below for info on the product and NEC 680.26.

Click the WaterBond picture below for info on the Water bonding and NEC 680.26(C)

Click the link below to learn about protection from Stray Currents and equipotential bonding of pools and decks. Here is info from NEETRAC www.dom.com/about/safety/pdf/pool_equi_bond.pdf