For those lucky enough to have a pool at their residence, swimming can be a great way to unwind during the summer months. While swimming pools are an excellent way to relax, stray voltage in the pool can pose a significant threat. Stray voltage typically occurs from improperly grounded pool equipment.
What is Stray Voltage?
Before you can figure out how to prevent stray voltage, you need to know what it is. In most layman’s terms, stray voltage occurs when unrestrained currents leak from an electrical source. If swimmers or pets come into contact, stray voltage can even be fatal.
Most initial shocks from stray voltages are less than 10 volts, which is not very strong. When a person steps into the pool or touches a handrail or ladder connected to the pool, they may feel a slight tingling or stinging sensation. Children are more sensitive to sensory input than adults, so they often notice these small shocks before adults.
A defective transformer or electrical cable can often be the source of stray voltage in a swimming pool. This leakage current then travels through the ground to dissipate its energy. Just like lightning, it uses the ground as a path.
In reality, these stresses are found underground in most homes. Your family could be at risk even if your home’s electrical system meets all applicable standards.
Common Sources:
- Damaged or melted neutral or ground wire systems
- Defective lighting systems
- Damaged or exposed buried electrical wiring
- Faulty overhead line “drops” (where power is drawn from the main line)
- Electrical panel problems
- Damaged pads under transformers can also introduce stray voltage.
- Various other sources
One of the most likely places to find stray voltages is in a swimming pool, simply because electrical current has a much less resistant passage in the presence of water. When current flows from an outlet to another conductive element, such as a a metal water pipe, metal beam or concrete slab, this is called “stray voltage”.
Until the power supply is interrupted or the energy source is removed, the electricity remains in the water. Poor electrical wiring, inadequate GFCI protection for outlets and circuits, and electrical cords and equipment that come into contact with water are the three most common causes of electrocution in swimming pools.
Identifying the cause of the problem
Electrocution in a swimming pool is very rare, but it is still a risk for anyone who owns a swimming pool. Therefore, it is important to know what to look for if there is electricity in the pool and how to turn it off.
It used to be common to embed metal reinforcing bars in concrete pavements (for concrete stability). Metal was the conductor of electricity of choice over concrete, and stray voltage was not a major problem at the time.
Stray current became a problem when the concrete industry began incorporating additional components into the mix and rebar was no longer required in every construction. As a result, touch voltage has been linked to far too many injuries and even deaths.
There is no visible sign or way to tell if the water in the swimming pool contains enough electricity to kill. Most of the time, people don’t feel the electric current immediately when they step into the pool. This is a lesson New Jersey homeowner James Volk learned firsthand.
A Brick family discovered an electric current running through their yard and pool. Now they are looking for help to close it. https://t.co/p5VoT9UfWe
— Asbury Park Press (@AsburyParkPress) September 7, 2022
“My wife, mother-in-law and daughter were in the pool and my wife went to clean the skimmer basket,” Volk told news sources. “When she put her hand in, she was so shocked she felt it down to her feet, like a tingling, a numbness.”
The whole family has learned to walk carefully in the pool area as some have experienced these tremors outside the pool. The family is currently investigating the cause of the issue and have closed their pool until the cause can be determined.
Protection of swimming pools from stray voltage
Protecting pool swimmers from stray voltage should be a top priority. With proper wiring, the risk of stray voltages can be greatly reduced. Wiring and grounding also work better. Therefore, the consideration of how to protect against stray current begins with the construction of the pool itself.
Stray voltage can appear suddenly when there are problems on the ground or neutral side of an electrical system. Devices that have worked flawlessly for years can fail if something out of the ordinary happens.
Any pool with underwater lights, a pump to move the water, or an electric heater has the potential for the water to become electrically charged if there is an electrical failure. Most experts would advise placing equipotential bonding grids under the pool and deck to provide an alternative path for stray voltage.
A pool should be electrically safe for swimming if it is properly constructed and has an equipotential deck surface with all of its components properly connected.
Shock Alarm – ESD (Electric Shock Drowning) protection system
If you suspect your pool has stray voltage, a device known as a “shock alarm” can be used to check for electricity in the pool water. When there is electricity in the water, the shock alarm will let you know by beeping and flashing red. This would indicate that there is current in the water and swimmers should stay outside. On the other hand, if the device is flashing green, this would indicate that there is no voltage and it is safe to enter the pool.
What to do if you encounter stray voltage in the pool
The best advice is to avoid exposure to stray voltages at all costs. Seek the help of a licensed electrician as soon as possible if you think you are having this problem near your pool or spa. Do not allow anyone, including humans and pets, near the pool until the problem is resolved.
The electrical code has evolved significantly over the past few decades. It’s possible that in many older pools, the wraps were never properly installed or constructed. A wiring error or a problem with your electricity company are other possibilities. There are a number of possible causes of stray voltage, so it’s best to have this checked and corrected by a qualified electrician. Most problems have very simple solutions.
