555.3 Require GFI on all conductors on dock

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fmtjfw

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Section/Paragraph: 555.3

New Text

555.3 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. Ground-fault protection shall be provided for all conductors on the structure over or adjacent to the water intended to provide berthing or moorage.

Exception: This shall not apply to circuits of less than 30 actual volts or telephone communications circuits.


Substantiation

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).

Circuits need to be protected their entire length. This new provision would require all conductors to be GFI protected prior to entering the dock area.

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

Inserted Deleted
 

GoldDigger

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Do you really mean to require ground fault protection for the grounded conductors of the circuit too? And just how would this be done?
"...for all conductors...."
 

fmtjfw

Senior Member
Do you really mean to require ground fault protection for the grounded conductors of the circuit too? And just how would this be done?
"...for all conductors...."

Thanks, good point. Although in a sense ground-fault does take into account grounding conductors in that a cross between the neutral and a grounding conductor on a loaded GFI will often trip it.

I'll fix it.
 

fmtjfw

Senior Member
555.3 Require GFI on all conductors, except grounding REVISED

555.3 Require GFI on all conductors, except grounding REVISED

Section/Paragraph: 555.3

New Text

555.3 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. Ground-fault protection shall be provided for all conductors, except grounding conductors, on the structure over or adjacent to the water intended to provide berthing or moorage.

Exception: This shall not apply to circuits of less than 30 actual volts or telephone communications circuits.


Substantiation

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).

Circuits need to be protected their entire length. This new provision would require all conductors to be GFI protected prior to entering the dock area.

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

Inserted Deleted
 

GoldDigger

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I don't think you quite got my point. I was referring to protection of grounded conductor (aka neutrsl) as well as the EGC. Does a standard GFCI breaker interrupt the neutral too? If not, somebody (not I) will argue that it is not protected.
 

fmtjfw

Senior Member
I don't think you quite got my point. I was referring to protection of grounded conductor (aka neutrsl) as well as the EGC. Does a standard GFCI breaker interrupt the neutral too? If not, somebody (not I) will argue that it is not protected.

Very good point. Some do, I don't if they all do now. In the transparent samples I've seen there appears to be a single, not two contacts.

"Service Station" breakers do open the neutral. Don't know if there are GFI / Service Station breakers and panels.
 

don_resqcapt19

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I don't think you quite got my point. I was referring to protection of grounded conductor (aka neutrsl) as well as the EGC. Does a standard GFCI breaker interrupt the neutral too? If not, somebody (not I) will argue that it is not protected.
That is a very good point, the GFP device needs to open the grounded conductor and maybe even the grounding conductor. Many of the issues around water are from elevated neutral voltages. That being said, I don't know of a device that is intended to detect elevated neutral voltages.
 

fmtjfw

Senior Member
Here's a NEMA presentation that shows modern GFCI receptacles and inlines tripping both hot and neutral, but GFCI breakers only tripping hot.

http://www.nema.org/Products/Documents/NEMA-GFCI-2012-Field-Representative-Presentation.pdf

Given the rule that you must preserve the grounding connection when a device is removed, you can't open the grounding wire on trip.

The worst case is a loaded circuit with a broken neutral energizing the water. Just looks like an essentially unloaded circuit to upstream GFI protector.

On the other hand we design 500 class circuits to not cause problems on a single failure and possibly cause a problem on a double failure.
The case here has two failures, open neutral and exposed neutral.
 

GoldDigger

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Location
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Here's a NEMA presentation that shows modern GFCI receptacles and inlines tripping both hot and neutral, but GFCI breakers only tripping hot.

http://www.nema.org/Products/Documents/NEMA-GFCI-2012-Field-Representative-Presentation.pdf

Given the rule that you must preserve the grounding connection when a device is removed, you can't open the grounding wire on trip.

The worst case is a loaded circuit with a broken neutral energizing the water. Just looks like an essentially unloaded circuit to upstream GFI protector.

On the other hand we design 500 class circuits to not cause problems on a single failure and possibly cause a problem on a double failure.
The case here has two failures, open neutral and exposed neutral.
So, basically, unless you change the wording of your proposed change, it will require the use of equipment that does not even exist yet. We all know how well that has worked in the past. :)
 

fmtjfw

Senior Member
So, basically, unless you change the wording of your proposed change, it will require the use of equipment that does not even exist yet. We all know how well that has worked in the past. :)

Ground Fault is a complete misnomer. A GFI does not know a ground fault from an ham sandwich.

I believe 210.8 discusses GFCI protection. It allows the use of GFCI breakers which do not open the neutral. Read it and tell me how I am surpassing it? Are you suggesting that my wording requires the GFI to trip the neutral. I don't see it that way.

A GFI protection device is one that looks for imbalances between the neutral and hot conductor (for 125V applications) it must monitor the neutral and so in some sense it protects the neutral. For instance if the neutral voltage is elevated and leakage current between it and another conductor (other than the associated hot conductor) exceeds the setting it trips, without power to the associated hot conductor, the elevated voltage on the neutral is likely to disappear. So the neutral is "protected".

A 250V GFI works in the same way only it looks for imbalances between two hots and a neutral (the neutral need not be used for the load).
 

GoldDigger

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Ground Fault is a complete misnomer. A GFI does not know a ground fault from an ham sandwich.

I believe 210.8 discusses GFCI protection. It allows the use of GFCI breakers which do not open the neutral. Read it and tell me how I am surpassing it? Are you suggesting that my wording requires the GFI to trip the neutral. I don't see it that way.

A GFI protection device is one that looks for imbalances between the neutral and hot conductor (for 125V applications) it must monitor the neutral and so in some sense it protects the neutral. For instance if the neutral voltage is elevated and leakage current between it and another conductor (other than the associated hot conductor) exceeds the setting it trips, without power to the associated hot conductor, the elevated voltage on the neutral is likely to disappear. So the neutral is "protected".

A 250V GFI works in the same way only it looks for imbalances between two hots and a neutral (the neutral need not be used for the load).

I am inclined to agree with you, and your position that protecting the grounded conductor is accomplished by sensing when it gets accidentally grounded along the way (or severed and grounded on the load side, which is worse) and therefore the current gets unbalanced.
But I am just playing devil's advocate that some inspectors and AHJ's (or even some CMP members) may hold the position that protecting the circuit can be done by opening the ungrounded conductor(s) when a fault is detected, but that protecting the conductors involves opening that conductor.
Among other things I would not like to see the CMP reject your input just because they misinterpret your wording and do not feel like correcting it themselves. :)
What you really mean is that the GFCI device should monitor all conductors (other than the EGC) and protect all circuits associated with that conductor, but that language is not common in the NEC either.
What I am not sure of either is why you insert the language about protecting all conductors instead of sticking with the concept of protecting all circuits.
 

GoldDigger

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One other comment as background for this discussion:
A ground fault is at least as likely to be in connected equipment as in the wiring. Is a ground fault in the middle of a heater winding a fault in the hot conductor? No. Is it a fault in the neutral? No.
It is a fault in the circuit, which includes whatever equipment is connected at the moment.
So on that basis protecting conductors is not sufficient, in addition to being hard to define.
 

fmtjfw

Senior Member
555.3 Require GFI on all conductors, except grounding REVISED 2nd time

555.3 Require GFI on all conductors, except grounding REVISED 2nd time

Section/Paragraph: 555.3

New Text

555.3 Ground-Fault Protection.
Ground fault protection shall be provided as required by 555.3(1) and (2).

(1) 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.

(2) Ground-fault protection shall be provided for all circuits on structures over or adjacent to the water intended to provide berthing or moorage.

Exception: This shall not apply to circuits of less than 30 actual volts or telephone communications circuits.

Substantiation

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).

Circuits need to be protected their entire length. This new provision would require all conductors to be GFI protected prior to entering the dock area.

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

Inserted Deleted

============================
Thanks to all who have commented on this topic.
You have greatly improved the submission.
I get hung up with honing the concept and neglect to look for model language elsewhere in the code. I end up suggesting "a different way to say the same thing" which is what I decry in others.

THANKS
 
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