CBS News reported that on September 3, a 17 year-old female was found dead in a neighborhood pool, and pulled from the water. At the time, authorities said they could not confirm how she died.
Wake County Inspections department issued a report on September 9, 2016 after being called upon to investigate the electrical wiring following the drowning death of the teen. Their report concluded that the pool pump motor failed and phase A faulted to ground. The fault current followed the only path available to it, the pool water, creating a voltage gradient across the pool and the pool equipment. Read the report.
Mike Holt's Comment: Apparently the pool bonding conductor made some continuity to the pool equipotential bonding system, because there were energized parts in the pool from the fault to the motor. The open feeder neutral prevented the fault current from returning to the neutral point of the utility secondary in sufficient magnitude to blow the fuse; resulting in energized metal parts. If the metal parts of the pool were bonded properly in accordance with 680.26, there would not have been any difference in potential between the pool water and metal parts; most likely this death would have been prevented.
Lessons learned:
1. You need to understand the Fundamentals of Electricity (http://www.youtube.com/embed/mpgAVE4UwFw) to ensure that your installations are always safe.
2. You need to understand the NEC Requirements for Bonding and Grounding in general, as well as for pools and spas. (https://www.youtube.com/watch?v=j7r1UyuIgss).
3. An effective ground-fault path is required for all circuits in accordance with Article 250. See http://www.youtube.com/embed/uMhCTiTMqUQ.
4. I strongly suggest that you visit http://www.mikeholt.com/swimmingpoolbonding.php so that you have access to the information on how to verify that the pools for all the people you know are properly bonded. Next month, I intend to visit the homes of all those I know, to verify that the bonding is proper. You should do the same after you have watched my video on how to do this - https://www.youtube.com/watch?v=Q8YLcXRo-Go&feature=youtu.be&t=132
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