Working on power lines, constructing and upgrading substations, and building new transmission lines comes with the risk of hazardous energy. Measures are always taken to ensure that lines are not energized while work is being performed, but this isn’t the only factor that contributes to hazardous energy. Understanding the potential risks and how to mitigate them is essential for protecting people at electrical utility work sites.
What Is Hazardous Energy?
Hazardous energy is an occupational safety term that encompasses any type of energy that can be hazardous to people. In the case of substations, transmission lines, and power lines, electrical energy can be released in a number of ways that are potentially hazardous if proper precautions are not taken. Potential hazards when installing or maintaining transmission and distribution substations include current flow in the grounding system, induced current, step and touch potential, and arc flashes.
Established safety protocol must be followed at all times to minimize reenergizing risk. In addition to lockout and tagout protocols designed to prevent the accidental release of electrical energy, creating an equipotential zone (EPZ) can also help protect crews on the ground at work sites.
What Is an Equipotential Zone (EPZ)?
Differences in electric potential can cause electric shock. When there is no difference in electric potential, there is no voltage, which means that electrons can’t flow through the body to cause an electric shock. Work areas around substations should always be grounded and bonded to create an equipotential zone, which reduces the differences in electric potential between objects or points on the body. The purpose of an EPZ is to equalize the electrical potential of conductive equipment, reducing the risk of electric shock.
How to Create an Equipotential Zone at a Remote Work Site
Existing substations will have an equipotential zone integrated into the infrastructure, often underground. However, it’s not safe to assume this is sufficient, especially with older structures. An equipotential zone should be created for any work being performed around a new or existing electrical utility site.
You can do this by using grounding grates that connect together to form a stable work surface that is also grounded. EPZ grounding grates create an equipotential zone where people can walk or drive without the risk of electric shock due to a difference in electric potential. Your equipotential zone should also include a fence so it’s clear where the safe area is, transition mats for walking on and off the zone, and clear signage warning about the dangers of hazardous energy.
Use SAFESTEP™ EPZ Grounding Grates today
You can’t rely on hidden grounding solutions at a work site—especially with older substations. Grounding grates are a solution that you can see and control, so you know exactly what area is protected.
YAK ACCESS and United Rentals offer SAFESTEP™EPZ grounding grates to reduce the risk of shock from hazardous electric potential. When installed, the grates create a bonded and grounded equipotential zone that can be customized for your work site. These galvanized steel mats link together, are bonded together with copper cables, and have integrated lug connectors for securing grounding cables. The grates and cables are reusable, built to last, and link securely for easy assembly and removal.
Unlike makeshift solutions that come with trip hazards, SAFESTEP™mats provide a seamless work surface and a stable foundation for people and equipment. They are also portable and reusable, so you can easily transport them between work sites.
Looking into EPZ grounding for your next project? Our team has solutions. Get in touch any time to explore your options and learn how EPZ grounding grates can help protect your crew.
