555.3 add E-Stops and signs

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fmtjfw

Senior Member
Section/Paragraph: 555.3

New and Revised Text

555.3 Ground-Fault Protection. Safety Provisions.
(A) Ground-Fault Protection.
The main overcurrent protective device that feeds the marina shall have ground fault protection not exceeding 100 mA. Ground-fault protection of each individual branch or feeder circuit shall be permitted as a suitable alternative.

(B) Emergency Disconnect System (EDS).
An electrical disconnect system consisting of emergency disconnect devices (EDD)s (mushroom pushbuttons, for example), and associated equipment, shall cause all electrical power to be removed from the entire docking structure, when an EDD is activated. Restoring power after the EDD has been used shall require an action by an authorized person using tools or a key.
EDDs shall be installed on any structure that has electrical wiring on it and provides berthing or moorage for boats or floating buildings. EDDs shall be in readily accessible locations, mounted not higher than 1.2 meters (4 ft.) above the deck. They shall be placed so that no location on the deck is farther than 15 meters (50 ft.) from a EDD when following a walkable path.
Berthing and moorage structures not containing electrical wiring but within 15 meters (50 ft.), measured in a straight line, of an electrified berthing or moorage shall also have EDDs installed as above.
Each EDD shall be marked ?EMERGENCY ELECTRICAL DISCONNECT?.
An EDS operating at over 30 actual volts shall have protection by a ground-fault circuit-interrupter (GFCI) for personnel.
The EDS shall either be electrically supervised or shall disconnect all electrical power if the system loses power or a device or conductor opens or is grounded.

Informational Note: Supervision circuits used in fire alarm systems that conform to NFPA 72-xxxx National Fire Alarm Code are acceptable for use as electrical supervision.

(C) Sign.
Permanent safety signs shall be installed with print legible at eighty feet and placed to give adequate notice to persons using or swimming near the boat dock or marina, of the electrical shock hazard risks of the waters around the boat dock or marina. The signs shall state: ?ELECTRICAL SHOCK HAZARD RISK: NO SWIMMING WITHIN 100 YARDS OF THE BOAT DOCK?.


Substantiation

For (B) and (C):
The water, electrical circuits, individually owned and maintained boats, and motion due to the water combine to make marinas and boatyards potentially hazardous locations for persons in the water. Current leakages occurring in the water may cause Electric Shock Drownings(ESD).

For (B):
If a person experiences this, the rescuers are quite likely to experience paralysis when entering the water. The only effective way to provide a safe environment for rescuers is to quickly turn off the power. NFPA 303 Fire Protection Standard for Marinas and Boatyards requires:

5.4.5.2 The equipment addressed in 5.4.5.1 [service equipment, including disconnecting equipment ... and the main switchboard or panel ....] shall be protected against access by unauthorized persons.

This is typically accomplished by placing it in locked fenced areas or locked cabinets, which limits immediate access for witnesses to ESD. The ability to turn the power off immediately may be the difference between life and death and in providing safety for rescuers. The use of "emergency stop Buttons" is a long standing way to provide immediate stopping of processes which threaten life or limb.

For (C):
An inexpensive way to reduce the people possibly exposed to ESD is to prohibit swimming in these areas. This requirement is copied from WV State Law that goes into effect 1-Jan-2015. Unfortunately signs can not prevent people from falling into the water accidentally.

For more information please view: http://www.electricshockdrowning.org/

Inserted Deleted
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
It does not address leakage that starts on a boat though.

best thing is not to try to deal with this as an electrical problem and just ban swimming near the dock.
 

fmtjfw

Senior Member
No swimming reduces the exposure

No swimming reduces the exposure

It does not address leakage that starts on a boat though.

best thing is not to try to deal with this as an electrical problem and just ban swimming near the dock.

The problem is banning falls. A recent study shows 12% of boat exhibit leakage as measured on their shore connections. This is the scary part. If you wire the marina properly you still have exposure. The cure would be to use GFCI everywhere, but there is no way the circuits would hold.
 
The problem is banning falls. A recent study shows 12% of boat exhibit leakage as measured on their shore connections. This is the scary part. If you wire the marina properly you still have exposure. The cure would be to use GFCI everywhere, but there is no way the circuits would hold.

If by your own admission banning fails, then why suggest a rule that requires a sign banning swimming within a given distance of the dock?
 

fmtjfw

Senior Member
If by your own admission banning fails, then why suggest a rule that requires a sign banning swimming within a given distance of the dock?

FALLS not FAILS. Banning swimming is very effective. It's hard have an Electric Shock Drowning without being in the water. But falls do occur and just posting signs does not mean that you suddenly drop all the other measures (GFI ...).
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
FALLS not FAILS. Banning swimming is very effective. It's hard have an Electric Shock Drowning without being in the water. But falls do occur and just posting signs does not mean that you suddenly drop all the other measures (GFI ...).

how many of the deaths from electric shock drowning were people who fell in though? Even if you have GFCI on shore, you can still get leakage from a boat and nothing in the electrical code will change that.

This is not really an electrical code problem. The states just need to ban swimming at marinas.
 

fmtjfw

Senior Member
how many of the deaths from electric shock drowning were people who fell in though? Even if you have GFCI on shore, you can still get leakage from a boat and nothing in the electrical code will change that.

This is not really an electrical code problem. The states just need to ban swimming at marinas.

I'm working with someone (Retired US Navy Capt) on incidence substantiation.

This is an electrical problem, swimming in a marina, will not electrocute you if the marina is not electrified.

The NEC has over 60 requirements for warning labels and signs.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I'm working with someone (Retired US Navy Capt) on incidence substantiation.

This is an electrical problem, swimming in a marina, will not electrocute you if the marina is not electrified.

The NEC has over 60 requirements for warning labels and signs.

It is not an NEC problem though as the problem can be readily solved by other means. In any case, most places it would not be within the purview of the electrical AHJ to ban swimming in a marina so it would be unenforceable even if you somehow got it put in the code.
 
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