jlauck
New User
- Location
- North Carolina
- Occupation
- Technology
I have an inground fiberglass swimming pool in my backyard. Recently I noticed a tingling sensation at one corner of the pool when touching the pool water with bare wet feet from the concrete pool deck. The location where this happened is also nearest the corner where the plumbing and electrical enter the pool deck area from the remote equipment pad up near my home's foundation. There is a retaining wall that the plumbing and electrical dives down behind before running under the pool deck. Upon investigation I found that the entire length of bare copper conductor between the pool and equipment pad has corroded away in the ground, AND the ground has a steep voltage gradient with a peak of about 40 volts right around the retaining wall.
It seems the bonding conductor suffered accelerated electrolytic corrosion due to the ~40 volts in the earth around it. The local electric utility has been out multiple times to "investigate" this elevated stray voltage as it is present even when my home's main breaker is off (but not when power is out to the entire neighborhood). It is obvious that the bonding grid for the pool must be repaired, but I am concerned that the steep gradient so close to the edge of the pool deck still presents a safety hazard. Although not required by the NEC, I could extend the bonding grid out to the retaining wall but then I would be importing that ~40V to the entire grid which seems like it could potentially create other problems down the road.
Like most or all of the U.S. I'm on a multi-grounded utility neutral, and although no neutral integrity issue has been found with my home's service, it seems there could be an issue with my neighbors or possibly the primary utility conductors at the street. Has anyone experienced this level of voltage gradient in the soil before without a fault someplace? Should I just hang up the hat with the utility company and simply repair the pool bonding grid, routing the conductor from the pool area to the equipment pad away from the area of the elevated voltage?
It seems the bonding conductor suffered accelerated electrolytic corrosion due to the ~40 volts in the earth around it. The local electric utility has been out multiple times to "investigate" this elevated stray voltage as it is present even when my home's main breaker is off (but not when power is out to the entire neighborhood). It is obvious that the bonding grid for the pool must be repaired, but I am concerned that the steep gradient so close to the edge of the pool deck still presents a safety hazard. Although not required by the NEC, I could extend the bonding grid out to the retaining wall but then I would be importing that ~40V to the entire grid which seems like it could potentially create other problems down the road.
Like most or all of the U.S. I'm on a multi-grounded utility neutral, and although no neutral integrity issue has been found with my home's service, it seems there could be an issue with my neighbors or possibly the primary utility conductors at the street. Has anyone experienced this level of voltage gradient in the soil before without a fault someplace? Should I just hang up the hat with the utility company and simply repair the pool bonding grid, routing the conductor from the pool area to the equipment pad away from the area of the elevated voltage?
