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Why don't Marinas have GFCI protection to prevent Electrical Shock Drowning?

  1. Jun 19, 2017 #1

    berkeman

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    There have been several stories in the news lately about swimmers getting killed by Electrical Shock Drowning (ESD) when swimming near docs in Marinas. The diagram at the following link shows how it happens, but I'm not understanding why electrical service to the docs isn't Ground Fault Circuit Interrupter (GFCI) protected? That's what GFCI breakers are for!

    http://www.electricshockdrowning.org/esd--faq.html

    Is there some fundamental reason that they can't be used? Are ground faults so common on Marinas tht there would be too many nuisance blows?
     
  2. jcsd
  3. Jun 19, 2017 #2
    No.

    For starters check https://en.wikipedia.org/wiki/National_Electrical_Code

    While the National Electric Code is a private standard and adopted all or in part for state and/or local construction manufacturing etc e.g.,manufacturers of boats. It in itself is just a recommendation for the safe use of electricity i.e. standards of good practice which industry and business usually follow. Hospitals in the US are held to these standards for example by the Joint Commission on the Accreditation of Hospitals which in a private organization that evaluates standards of practice of hospitals for patients and employees.

    This is an short interesting article by a forensic engineering firm http://kleinholzinc.com/2012/12/new-ground-fault-detection-requirements-for-marinas/ that explain some of the issues for marinas.
     
  4. Jun 19, 2017 #3
    Would a GFCI on the dock electrical service protect against a boat that is electrifying the water? The dock GCFI could well as not detect anything out of the ordinary. False sense of security for potential swimmers. Swimmers STAY away from docks with electrical connections.

    See picture 3 for the current bypass around the dock service when there is a broken ground on the boat and electrical short.
    Picture 2 would mean do not for example go into water to fix your metal propeller without disconnecting service to the boat.

    At least that is the way I see it.
     
  5. Jun 19, 2017 #4
    Having asked this question myself many years ago(being EE and into sailing) ... if I recall this correctly - the problem is the various states of repair and condition of ALL of the vessels as well as the marina wiring itself. It is subjected to the harsh marine environment - AND the constant supply of electricity is necessary to keep many boats floating.

    In this setting is it nearly impossible to prevent the low level leakage detected by GFCI - which would lead to daily tripping of the breaker / protection, and could be very difficult to locate the fault(s) - all adding to the time that the power is off. Since most large boats (pleasure and commercial) require continuous power to keep the bilge pumps running, the "neusance" tripping can lead to other problems. For example a sinking boat is likely to catch fire as battery system are shorted by floodwater - but the power is off and now you do not have fire pumps. So overall the need to maintain the electrical feed becomes higher priority than benefit of the GFCI protection.

    I have not paid attention to the changes in NEC regarding this topic - but I can not imagine retrofitting any GFCI in any but the most pristine (expensive) marinas even being possible - without a complete rewiring of the whole marina.
     
  6. Jun 19, 2017 #5

    anorlunda

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    I'm sure that everything you said is true. I'm also convinced that if it was required, there would be grubling for a few weeks, but that marinas and boat owners would come into compliance in a short time.

    If you need a bilge pump to stay afloat, you need a plan to handle non-nuisance power outages. Once you have that, it covers nuisance cases also.

    There is more than safety at stake. Galvanic corrosion caused by stray leakage currents in the water at marinas can cause extremely expensive damage to all vessels in range.
     
  7. Jun 19, 2017 #6
    In the past poorly maintained or constructed boats were considered the primary source of electrical safety problems in marinas. If a boat tripped a GFCI that should tip off the owner that the boat has a problem and not ignored.
     
  8. Jun 19, 2017 #7
    Question is "What is a 'safe' level of trip?"
    Leakage current is unavoidable.
    Are we taking about Class A CFCI at the pedestal? I don't think so. That's too low to power the boat.
    So it ( trip current ) is something higher, and then something higher still at the distribution point.
    Leakage current in the water bypasses the CFCI.
    Some areas could still be shocking and unsafe for those entering the water due to the cumulative effect of many boats.
    Stay out of the water around the dock.
     
  9. Jun 19, 2017 #8

    berkeman

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    Great responses, thanks everybody. Just wondering, how come there are not routinely lots of dead fish floating to the surface around Marinas? Does their body construction somehow keep the electric shock currents out of their cardiac core? Should we coat our kids with conductive sunscreen before allowing them so go swimming?
     
  10. Jun 19, 2017 #9

    rbelli1

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    Maybe

    https://what-if.xkcd.com/

    BoB
     
  11. Jun 20, 2017 #10

    anorlunda

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    I think the links provided by @gleem in #2 answer your questions.
     
  12. Jun 20, 2017 #11

    russ_watters

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    True or not, I'm also very uncomfortable with the logic: Applied to a house, it is basically saying that the code should be made more lenient because old/decreped houses can no longer meet the requirements for safety because they are in disrepair. Isn't that logic exactly the opposite of what building codes are for?

    I've seen things in the code that don't make sense to me or make some logical sense but are burdensome for a minor benefit. But this issue actually kills people. Often. To me, that makes it worthy of more serious treatment even if it means [*horror*] that boat owners have to keep their boats properly wired in order to be allowed to connect to shore power.
     
  13. Jun 20, 2017 #12

    I like Serena

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    I'm still a bit confused.
    Wouldn't it suffice if every shore outlet would have a strict protection in place that the difference between the hot wire and the neutral wire is always low enough, or otherwise shut down - quickly?
    That would only require that every shore outlet is refitted if need be, and old decrepit boats and/or boats with a problem won't be ensured of power, as it should be.
    And it would be only single boats that won't have power, and not he whole marina, so there should not be a serious issue with safety (e.g. fire) regulations either.
     
  14. Jun 20, 2017 #13
    This seems to a "mile in their shoes" issue, everything about the sea, boats, the marine environment is radically different than a residence. IMO - a moderately sized marina with 100+ boats/slips, would be a nightmare to be converted (retrofitted) to GFCI - still I found this pretty good PPT,

    Interesting points - he recommends doing the required annual inspections off season ( fewer boats, fewer problems), and the note to NEVER turn off power to a boat.

    Every single boat, junction box, cable run, shore power cable, breaker box. etc would need to be upgraded - this would not be a few weeks of grumbling - but a year of work, and then double the marina staff and training them, to be safely tracking down a GF daily. Also - the rules and liability of a marina whit respect to the boat - probably has some peculiarities, relating to issues similar to Sea Law - I doubt it is as easy as just turn off the power to Boat X when it has leakage.
     
  15. Jun 20, 2017 #14

    CWatters

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    The article gleem linked to is worth a read. It points out the benefit of having a layered approach with different trip currents for individual boats and docks to localise problems. Also shows how to turn a problem into a money making opportunity.

    I suspect marina owners also have a responsibility/liability for the safety of their own staff or visitors that might end up in the water accidentally so banning or blaming illegal swimmers isnt the answer.
     
  16. Jun 20, 2017 #15
    Here is an example of a pedestal - good for 4 slips. Note - only the "local" outlet, not the shore power ones ( connected to the boats) are GFCI. Granted this is retail pricing, for wholesale, maybe 1/2 to 2/3 of that price. Anything here needs to be "hardened" to the environment, a basic steel junction / breaker box, can be used and installed to meet code, but will die in 5-10 years.

    Steel or aluminum - great for mechanical strength, needed due to the nature of dock activities, but both corrode. Plastic, PVC - great for corrosion, but not physically very durable - and then the UV issues.
     
  17. Jun 20, 2017 #16

    anorlunda

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    When the National Electrical Code (NEC) makes a stand, you can expect it to arrive on your doorstep before long. If government does not incorporate the NEC by reference, your insurance company will demand compliance as a condition for continuing coverage.

    Imagine yourself defending a lawsuit from someone electrocuted at your facility. The plaintiff's lawyer asks, "Is your facility compliant with the NEC?" "I don't know." or "No, that's too much trouble." will not impress the jury.
     
  18. Jun 20, 2017 #17

    anorlunda

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    That slide presentation you linked in #13 suggests that protection may be provided at the dock head or centrally for the whole marina rather than at each pedestal. It also said that per-pedestal protection can be very expensive.

    The advantage of per pedestal protection is rapid diagnosis when a bad boat trips it instantly when they plug in. But I can think of less expensive ways to accomplish that.
     
  19. Jun 23, 2017 #18

    I like Serena

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    I've been reading up a bit, and I think it's only now that I understand the problem a bit better.
    Until now we've had Earth Leakage Circuit Breakers (ELCB) in place.
    And if I understand correctly, most marina's actually have those (do they?).
    It detects a current on the earth wire and shuts down if need be.
    Friends of mine told me this happens all of the time on a marina (that it shuts down when there's no real earth leak), at least in my country (Netherlands).
    I guess that makes sense, since a boat will always have some charge on its mass, so at least initially an earth current will always flow.
    And with all that water around, there will be earth leaks anyway.
    It also means that if the earth wire is broken, we have no protection - not inside the boat and not outside of the boat, which is what would (or could) be causing ESD.

    Instead we're talking about Ground Fault Circuit Interrupters (GFCI) now.
    Those detect a difference between the hot wire and the neutral wire.
    If there's a difference we're obviously leaking power, whether the earth wire is broken (or intentionally interrupted because it's so 'annoying') or not.
    It actually makes the earth wire sort of redundant.
    And it should protect anyone inside or outside of the boat if detected quickly enough with a low enough tolerance.

    So I guess we're talking about replacing ELCB's by GFCI's? Or simply adding GFCI's?
    If so, that suggests that most personnel actually already has experience with solving earth leaks, so little new training would be required.
    And if a pedestal lasts indeed only 5-10 years, all pedestals can effectively be replaced within 10 years by improved models without unreasonable extra costs.

    For the record, I'm not an expert, so please correct me if I'm wrong. I'm just interested in this thread.
     
    Last edited: Jun 23, 2017
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