With dozens of papers and videos created around electric shock drowning (ESD) you would think that living and conducting electrical inspections in Michigan, a state with 3,288 miles of freshwater shoreline and numerous marinas, I would have known about ESD. Well, you would be wrong; I had no idea what ESD was until I started working at NFPA. I wondered if I was the only electrical inspector who was unaware, so I asked several inspector and electrician friends, and the answer was overwhelmingly, “No I do not, what is it?” This was shocking to me, but also provided me an opportunity to educate them. So, how can an electrical inspector have an impact? We must first answer the question of; what is ESD?
According to the Electric Shock Drowning Prevention Association, it is the result of the passage of a typically low-level AC current through the body with sufficient force to cause skeletal muscular paralysis, rendering the victim unable to help himself / herself, while immersed in freshwater, eventually resulting in drowning of the victim. Higher levels of AC current in the water will also result in electrocution. It has been said that ESD is the catch-all phrase that encompasses all in-water shock casualties and fatalities. ESD occurrences happen more in freshwater environments than in salt water, which is why ESD is a concern around freshwater docking facilities, marinas, lakes, and ponds. Creating a specific code section in the NFPA 70®, National Electrical Code® (NEC®) for ESD may sound simple, but it is not. ESD is not a piece of electrical equipment or an electrical conductor but rather a phenomenon that can occur where boats in water are connected to shore power electricity. ESD is impacting the construction of boats, marinas, and docking facilities, which may help reduce occurrences of ESD. Even though ESD isn’t specifically addressed in the NEC, it has had a significant impact on recent changes that have been made in it.
New solutions towards helping to eliminate ESD have become a regular subject in the code making process, public inputs, and comments for potential new NEC requirements. Although not finalized yet, suggested changes to the 2023 NEC that electrical inspectors should be aware of and that could have a positive impact on ESD reduction are:
Emergency electrical disconnects within sight of the marina power outlets, which allows bystanders to quickly de-energize power to the boat and safely release a person who may be suffering an electric shock.
Adding equipotential planes and bonding of equipotential planes that could help mitigate step and touch voltages for electrical equipment that supply power to the equipment.
Requiring modified, repaired, or replaced equipment be updated to current provisions due to exposure to harsh environments.
As conversations around ESD continue throughout the code development process it is important to remember the current requirements found in the 2020 NEC, and how electrical inspectors can use those sections to make an impact in reducing ESD. Through enforcement of electrical codes the inspector can help educate and inform owners and installers about ESD risks. Here are just a few code sections inspectors might want to be looking for:
Signage - You might wonder, since when do electrical inspectors enforce non-electrical signage around marinas, boatyards, and docking facilities and how can they help prevent ESD? They can do it by continuing to warn everybody of the true dangers facing them. These areas are challenged with constantly changing environments because numerous boats in various degrees of electrical repair travel in and out of these facilities. This can make a place you may otherwise consider swimming in, potentially unsafe due to low-level AC current (leakage current). Installing permanent safety signs around marinas, boatyards and docking facilities gives notice of electrical shock hazard risks to persons within those areas. Signs should say more than “No Swimming” since some people may not take that warning seriously and swim anyway. Code language was added to have signs state: “No Swimming: “WARNING-POTENTIAL SHOCK HAZARD-ELECTRICAL CURRENTS MAY BE PRESENT IN THE WATER.” To aide in further preventing ESD, docking facilities was added in the 2020 NEC to the already existing areas of marinas and boatyards found in section 555.10.
Ground-fault protection - Changes in the 2020 NEC, Article 555 Marinas, Boatyards, Floating Buildings, and Commercial and Noncommercial Docking Facilities address both ground-fault protection of equipment (GFPE) and ground-fault circuit interrupter (GFCI) protection. With cumulative effects of leakage current causing excess tripping of 30 milliampere GFPE devices, changes were made to code language that increased GFPE current settings not to exceed 100 milliamperes on feeders and branch circuits, which will cause inspectors to alter how they enforce this section. This change helped to facilitate more dependable power for marinas and docking facilities. However, individual branch circuits feeding single shore powered receptacles, must have individual GFPE devices set to open at currents not exceeding 30 milliamperes. Coincidentally, this requirement matches main breaker settings in boats manufactured after July 31, 2017.
Leakage current measurement device - New 2020 NEC language allows electrical inspectors to require marinas, boatyards and docking facilities that have more than three receptacles supplying shore power to boats to have a leakage current measurement device available on site. This device would allow facility operators to isolate and notify boat owners of leakage current so repairs could be made by a qualified person, thus helping to eliminate a potential ESD risk.
Private docks - Locations where ESD hazards may easily get overlooked or not inspected are on lakes surrounded by homes with private docks. These homes don’t always have shore power but may have electrically powered boat hoists. Section 555.9 was added requiring boat hoist outlets not exceeding 240-volts installed at dwelling unit docking facilities have GFCI protection for personnel.
We have seen notable code changes within Article 555 over the last several cycles. Prior to the 2017 NEC, warning signs around marinas, boatyards, or docking facilities were not an NEC requirement, but they are now. GFCI and GFPE have had changes made within Article 555 over the 2017 and 2020 NEC cycles. Boat hoist GFCI protection was added to the 2020 NEC, plus numerous potential changes that may occur in the 2023 NEC cycle. There’s been a lot of positive influence on the codes because of the risks surrounding ESD, including regulating electrical requirements in marinas, boatyards and docking facilities, rendering them much safer now. But you still can’t swim there!
As inspectors, we can help raise awareness of ESD in our communities. It starts with educating ourselves. Visit NFPA’s ESD web to learn more about this topic and ways to help mitigate the risk of ESD.