ELECTROCUTION IS A LEADING CAUSE OF DEATH AMONG CONSTRUCTION WORKER FATALITIES, ACCOUNTING FOR 8.5% OF TOTAL FATALITIES IN 2018.
The primary cause of death over 50% of these fatalities was contact with live electrical equipment and wiring. Even though overhead electrical work has long held consistent standards, safety protocols for ground crews on de-energized sites are often more ad-hoc and improvisational, which means increased risk for workers.
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G round crews may suffer injury or even death from step and touch potential. Step potential is when an individual steps on a surface with high voltage and the current carries from one foot through the rest of their body. Touch potential is when the current carries through an individual’s body as a result of a direct touch. It takes 50 volts to break the electrical resistance of skin and cause injury. Serious injuries, or even death, may occur from exposure levels of no more than 50 milliamps.
The IEEE recommends the accepted practice of developing an equipotential zone (EPZ)1, which bonds together all accessible conductors, structures, components and equipment through at least one low-resistance paths. This bonding practice limits voltage exposure to the workers on a de-energized construction site. Grounding protection works to discharge voltage from nearby energized objects, reducing voltage to below a level that might cause injury to a worker.
While grounding causes the immediate operation of a circuit protective device to protect the equipment, a grounded circuit still has an active current which can contain voltage. To protect personnel on the ground from this voltage potential, it is essential to implement bonding.
THE DANGERS OF MAKESHIFT SOLUTIONS
Many contractors believe that dropping chain-link fencing, wiring or other makeshift solutions are good enough when it comes to protecting their employees. What they fail to consider, however, is the risks that these thrown-together systems present. Because they are not made to be walked on or rolled over with machinery, they can deform or break apart under stress. This creates trip-and-fall hazards in addition to dangerous gaps in what little protection they provide against high voltage.
Using timber or composite mats is another common strategy that does more harm than good. That’s because these can bend, crack and decompose over time. They won’t protect your workforce from electrical discharges, touch-and-step potential or other hazards the same way a quality EPZ grounding system could.
Choosing A High-quality EPZ Grounding System
While it’s possible to create makeshift EPZ systems, it’s not a good idea to do so for the safety and business reasons outlined above.
Instead, when choosing an EPZ grounding system to protect your ground workers, consider these factors:
- Durability and reusability
Is the system reusable without depreciation to the quality of the structure? Using galvanized steel is a good option for ensuring high-quality materials that won’t break down over time.
- Adheres to Standards
Does the system meet the ASTM F855-2015, IEEE 80-2013, or IEC 62271-102 Standards? Choose a system that has been tested in real-world scenarios to ensure that it will adequately reduce voltage from step or touch potential below any hazardous levels.
Has the system passed the following tests?
- Electrical Short Circuit Capacity Test
- Grade 5 Fault Current Test
- Electromagnetic Induced Current Test
- Consistent product quality
Does the provider manufacture a consistent product that you can rely on? Pay attention to brand reviews and reputation to ensure that you have access to a consistent, high-quality product.
- Best-in-Class Worker Safety
Choose a high-quality, performance-tested EPZ system for your grounding and bonding on de-energized work sites. It is possible to provide the same safety protections to your on-the-ground workers as you would to overhead utility workers. This will deliver a best-in-class protective environment that exceeds OSHA standards.
A BETTER SOLUTION
Made from all-in-one galvanized steel grates, SAFESTEPTM EPZ grounding grates offer superior protection in these high-voltage situations. They’re built to withstand heavy loads and extensive use. Combined with how easy they are to install and dismantle, these can be a viable solution for your jobsite needs.
1 IEEE P1048a – IEEE Draft Guide for Protective Grounding of Power Lines Amendment to Guide for Protective Grounding of Power Lines