Case Study: Missing Ground Prong Results in a Fatality
A female assistant manager of a swim club was instructed to add a certain chemical to the pool.
She went down into the pump room, barefoot. The room was below ground level, and the floor was covered with water. She filled a plastic drum with 35-40 gallons of water, then plugged a mixing motor into a 120-volt wall outlet and turned on the motor. The motor would be used to mix the water and the chemical, then the solution would be added to the pool. While adding the chemical to the water in the drum, she contacted the mixing motor with her left hand. Apparently, the motor had developed a ground fault. Because of the ground fault, the motor was energized and she was electrocuted. A co-worker found the victim slumped over the drum with her face submerged in water. The co-worker tried to move the victim but was shocked. The assistant manager was dead on arrival at a local hospital.
An investigation showed that the mixing motor was in poor condition. The grounding pin had been removed from the male end of the power cord, resulting in a faulty ground. The circuit was equipped with a GFCI, but it was not installed properly. A properly wired and functioning GFCI could have sensed the ground fault in the motor and de-energized the circuit.
Take a look at what could have been done to prevent this death:
- The employer should have kept the motor in better condition. Power cords should be inspected regularly, and cords missing ground prongs should be removed from service.
- All pool-area electrical circuits should be installed by qualified electricians.
- The victim should have worn insulating boots or shoes since she was handling electrical equipment.
- The employer should have followed the law. The NEC requires that all pool-associated motors have a permanent grounding system. In this case, this regulation was not followed. Also, electrical equipment is not permitted in areas without proper drainage.
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1-4. What action is required if the ground prong is missing from the male end of a power cord?
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