Electric Shock Drowning 07/22/2015 Ed Lethert Electric Shock - PowerPoint PPT Presentation

Electric Shock Drowning Remember: An in-the-water shock hazard can exist wherever shore-powered AC electrical equipment is located in the water, over the water, or adjacent to the water … regardless of its function 07/22/2015 Ed Lethert 42

Electric Shock Drowning Water Leakage Currents 07/22/2015 Ed Lethert 43

Electric Shock Drowning We know a whole lot more about ESD, water-borne leakage currents and voltage gradients thanks to the extensive and thorough investigative work of Capt. David Rifkin (USN, Ret) and James D. Shafer 07/22/2015 Ed Lethert 44

Electric Shock Drowning This significant and ground-breaking work by David Rifkin and James Shafer, funded by the US Coast Guard, has provided us with a wealth of data on In- Water Shock Hazards and ESD David Rifkin's research is ongoing and this 150+ page work is one that your presenter references often 07/22/2015 Ed Lethert 45

Electric Shock Drowning Available at www.qualitymarineservices.net 07/22/2015 Ed Lethert 46

Electric Shock Drowning Kevin Ritz is a major and long-time contributor to ESD awareness, research and prevention. He lost his son of 8 years, Lucas Ritz, in 1999 as the result of Electric Shock Drowning 07/22/2015 Ed Lethert 47

Electric Shock Drowning The research by David Rifkin and James Shafer has shown that ESD is a fresh water phenomenon This is due principally to the much lower conductivity (much higher resistance) of fresh water The greater part of the in-water current will flow through the human body with a lesser amount flowing around it 07/22/2015 Ed Lethert 48

Electric Shock Drowning Fresh Water Water Current Current Source Current Source Body Current Water Current Voltage Gradient 6 Ft Body current is large relative to water current Voltage Gradient = 23.8 Volts --- Very Lethal 07/22/2015 Ed Lethert 49

Electric Shock Drowning Causes of Water Leakage Currents 07/22/2015 Ed Lethert 50

Electric Shock Drowning To establish dangerous levels of leakage current flow in the water — and thus produce the resulting lethal voltage gradients — two conditions must be met 07/22/2015 Ed Lethert 51

Electric Shock Drowning First … There must be some form of electrical fault (hot to ground) at some point in the AC system ( AC powered wiring or equipment ) This will be a low level fault current as opposed to the high level of current that occurs as the result of a short circuit The low level fault current is not enough to trip a circuit breaker … so it remains continuous and undetected 07/22/2015 Ed Lethert 52

Electric Shock Drowning Second … There must be a failure in the shore power bonding (grounding) system … the equipment bonding/grounding path • Total failure (open circuit) • Very seriously degraded wiring or connection 07/22/2015 Ed Lethert 53

Electric Shock Drowning When these two conditions exist at the same time, any underwater metals — which are no longer bonded back to the AC source — become energized to lethal voltage levels The difference in voltage between these energized metals and the power source ground establishes dangerous currents and voltage gradients in the water 07/22/2015 Ed Lethert 54

Electric Shock Drowning A person finding themselves in this "charged" water can experience a dangerous AC current passing through their body When this current is high enough, nominally in the range of 10 or more milliamps ( that's thousandths of an ampere ), paralysis is likely to occur, resulting in the inability to remain afloat, followed by drowning 07/22/2015 Ed Lethert 55

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Electric Shock Drowning 07/22/2015 Ed Lethert 58

Electric Shock Drowning Invitation to an ESD Incident 07/22/2015 Ed Lethert 59

Electric Shock Drowning 07/22/2015 Ed Lethert 60

Electric Shock Drowning 07/22/2015 Ed Lethert 61

Electric Shock Drowning One of the 'HOT' conductors 07/22/2015 Ed Lethert 62

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Electric Shock Drowning Which is why … Harbor Cove Marina, Duluth, MN 07/22/2015 Ed Lethert 69

Electric Shock Drowning NO SWIMMING OFF OF BOATS OR DOCKS Minnetonka Power Squadron Island Facility, Lake Minnetonka 07/22/2015 Ed Lethert 70

Electric Shock Drowning When Is It "Safe" to Go Into the Water? 07/22/2015 Ed Lethert 71

Electric Shock Drowning Safe is defined in Webster's 1828 Dictionary as 1. Free from danger of any kind 2. Free from hurt, injury or damage 5. Placed beyond the power of doing harm 07/22/2015 Ed Lethert 72

Electric Shock Drowning When is it "safe" to … ? Careful consideration should be given to any use of the word " safe " when working or playing with or near electrically connected equipment that is in, on or near the water 07/22/2015 Ed Lethert 73

Electric Shock Drowning The term "safe" to enter the water is risky in itself and should never be used where and when shore power is installed and used, or in the context of water leakage currents Example – BoatUS Article 07/22/2015 Ed Lethert 74

Electric Shock Drowning The term "degree of risk" would be more suitable and excludes any inference that somehow absolute safety is guaranteed 07/22/2015 Ed Lethert 75

Electric Shock Drowning So when is the risk of ESD "very low"? Opinions vary somewhat, but there is general agreement among experts that a minimum distance of between 150 feet and 300 feet from active AC electrical systems would reduce the danger of ESD to "very low risk" (and therefore acceptable?) levels for recreational activities 07/22/2015 Ed Lethert 76

Electric Shock Drowning It could be considered "very low risk" to enter the water (for inspection, maintenance and repair purposes) where ALL nearby shore power is switched off AT THE POWER SOURCE This would include securing ALL nearby on-board generators and inverters 07/22/2015 Ed Lethert 77

Electric Shock Drowning What about someone who falls into the water inadvertently (or is just plain careless regarding their well-being)? There are some visual checks and electrical tests that can be performed on a regular basis to reduce the risk of in- water shock for these individuals 07/22/2015 Ed Lethert 78

Electric Shock Drowning It is never "safe" to enter the water in the vicinity of shore powered watercraft or equipment … for any reason … EVER! … while any nearby circuits are energized! 07/22/2015 Ed Lethert 79

Electric Shock Drowning Checking the Shore System Wiring 07/22/2015 Ed Lethert 80

Electric Shock Drowning When checking the shore system at the dock outlet, there is considerably more to it than just checking for voltage and polarity 07/22/2015 Ed Lethert 81

Electric Shock Drowning More information is required which means more sophisticated testing is required. 07/22/2015 Ed Lethert 82

Electric Shock Drowning 07/22/2015 Ed Lethert 83

Electric Shock Drowning Checking for Leakage Current 07/22/2015 Ed Lethert 84

Electric Shock Drowning 07/22/2015 Ed Lethert 85

Electric Shock Drowning Hioki 3283 Excellent for ESD work True RMS Very accurate Reads down to 0.01 mA Cost is ≈ 350.00 07/22/2015 Ed Lethert 86

Electric Shock Drowning Prevention 07/22/2015 Ed Lethert 87

Electric Shock Drowning NO SWIMMING OR WADING DO NOT ENTER THE WATER RISK OF ELECTRIC SHOCK Signage 07/22/2015 Ed Lethert 88

Electric Shock Drowning 07/22/2015 Ed Lethert 89

Electric Shock Drowning Ground Fault Protection 07/22/2015 Ed Lethert 90

Electric Shock Drowning Ground Fault Protection Class A GFCI Receptacle (5 mA Trip) 07/22/2015 Ed Lethert 91

Electric Shock Drowning Ground Fault Protection Class A GFCI Breaker (5 mA Trip) 07/22/2015 Ed Lethert 92

Electric Shock Drowning Ground fault (GFCI protection required for 125V, 15 and 20 amp receptacle outlets: • Swimming Pools (1971) • Located Outdoors (1971) ** • Bathrooms (1973) • Garages (1978) • Spas and Hot Tubs – incl hardwired (1981) • Boat Houses (1987) ** • Boat Hoists – incl hardwired (2005) ** 07/22/2015 Ed Lethert 93

Electric Shock Drowning Ground Fault Protection Disconnect Switch at Accessible Location 07/22/2015 Ed Lethert 94

Electric Shock Drowning EPO Switch for Marinas ? 07/22/2015 Ed Lethert 95

Electric Shock Drowning Codes and Standards 07/22/2015 Ed Lethert 96

Electric Shock Drowning Insure Compliance with Codes and Standards NFPA 70 National Electrical Code Article 555 Marinas and Boatyards Mandatory Compliance Required in Minnesota Shore Cord Marina Power 07/22/2015 Ed Lethert 97

Electric Shock Drowning ARTICLE 555 — Marinas and Boatyards [2014 NEC] 555.1 Scope. This article covers the installation of wiring and equipment in the areas comprising fixed or floating piers, wharves, docks, and other areas in marinas, boatyards, boat basins, boathouses, yacht clubs, boat condominiums, docking facilities associated with residential condominiums, any multiple docking facility, or similar occupancies, and facilities that are used, or intended for use, for the purpose of repair, berthing, launching, storage, or fueling of small craft and the moorage of floating buildings. Private, noncommercial docking facilities constructed or occupied for the use of the owner or residents of the associated single- family dwelling are not covered by this article. 07/22/2015 Ed Lethert 98

Electric Shock Drowning ARTICLE 555 — Marinas and Boatyards 555.1 Scope. This article covers the installation of wiring and equipment in the areas comprising fixed or floating piers, wharves, docks, and other areas in marinas, boatyards, boat basins, boathouses, yacht clubs, boat condominiums, docking facilities associated with one-family dwellings, two-family dwellings, multifamily dwellings, and residential condominiums, any multiple docking facility, or similar occupancies, and facilities that are used, or intended for use, for the purpose of repair, berthing, launching, storage, or fueling of small craft and the moorage of floating buildings. Proposed change in scope for inclusion in 2017 NEC 07/22/2015 Ed Lethert 99

Electric Shock Drowning Typical ESD Event and Response 07/22/2015 Ed Lethert 100