# Ground fault protection of feeders for marinas



## electricalperson (Jan 11, 2008)

how do you provide GFPE for marina feeders? do you use a GFCI breaker or do they make a specific device used in this type of application?


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## BBQ (Nov 16, 2010)

electricalperson said:


> how do you provide GFPE for marina feeders? do you use a GFCI breaker or do they make a specific device used in this type of application?


1) Why would I want GFP the feeder if under 1000 amps at 480? 


2) GFP is equipment protection, GFCI is people protection. They are not interchangeable.


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## electricalperson (Jan 11, 2008)

i dont have a 2011 code but i believe GFPE is now required on feeders in marinas

http://forums.mikeholt.com/showthre...-555.3-Ground-Fault-Protection-of-Main-Feeder


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## HARRY304E (Sep 15, 2010)

electricalperson said:


> how do you provide GFPE for marina feeders? do you use a GFCI breaker or do they make a specific device used in this type of application?


 Take a look at Article 555.19(B)..There is no requirment that the feeder be GFCI protected...


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## BBQ (Nov 16, 2010)

electricalperson said:


> i dont have a 2011 code but i believe GFPE is now required on feeders in marinas
> 
> http://forums.mikeholt.com/showthre...-555.3-Ground-Fault-Protection-of-Main-Feeder


I see, well it is asking for no more than 100 ma GFP. 

I do not know what device would be appropriate for that and I really wonder how many nuisance trips this 'less than 100 ma' GFP is going to cause.

Glad I don't do marinas. :thumbsup:


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## jwjrw (Jan 14, 2010)

From the 2011 NEC


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.


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## electricalperson (Jan 11, 2008)

HARRY304E said:


> Take a look at Article 555.19(B)..There is no requirment that the feeder be GFCI protected...


what about article 555.3


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## BBQ (Nov 16, 2010)

HARRY304E said:


> Take a look at Article 555.19(B)..There is no requirment that the feeder be GFCI protected...


Take a look at 2011 555.3.


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## electricalperson (Jan 11, 2008)

i actually wired a marina and all of its docks with shore power a few years ago. we had welder receptacles and fancy shore power stations on the docks. we did not put GFPE on the feeders. the regular 120v receptacles on the docks were gfci's the entire station just required a feeder and it had lights, breakers and 3 phase receptacles built in for the boats to attach too


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## HARRY304E (Sep 15, 2010)

BBQ said:


> Take a look at 2011 555.3.


Woops i missed that thanks BBQ..:laughing:


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## BBQ (Nov 16, 2010)

HARRY304E said:


> Woops i missed that thanks BBQ..:laughing:



So did I, I did not know about it until electricalperson brought it up. :thumbsup:


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## HARRY304E (Sep 15, 2010)

BBQ said:


> So did I, I did not know about it until electricalperson brought it up. :thumbsup:


My 2011 NEC handbook should be here any day now..:thumbup:

I have the 2011 on pdf but i still like fliping through the Book.:thumbsup:


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## electricalperson (Jan 11, 2008)

so how would we go about providing the protection required by 555.3? what are the devices?


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## electricalperson (Jan 11, 2008)

i never seen 30 mA or 100mA breakers before. im thinking the breaker probably already has GFPE built in with adjustable dials on the face of it?


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## hardworkingstiff (Jan 22, 2007)

Here is one option.

http://www.eaton.com/powerpedestal/...onProducts/MarinaGroundFaultMonitor/index.htm

I've always like their products. IMO, some of if not the best power centers in the business. The business was started by an electrician and Eaton bought them a some years ago.

Cost of marina wiring is getting prohibitive.


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## electricalperson (Jan 11, 2008)

hardworkingstiff said:


> Here is one option.
> 
> http://www.eaton.com/powerpedestal/...onProducts/MarinaGroundFaultMonitor/index.htm
> 
> ...


i seen those before but 555.3 requires the power to be shut off. it only requires GFPE 100mA or less on main feeders. im not sure if they mean the feeders that supply each shore power station or what. im sure if you run a 100 amp feeder or something like that too a shore power station on the dock you can put a GFCI breaker in. i dont know if thats the best idea or what


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## electricalperson (Jan 11, 2008)

im sorry if what i say doesnt make sense. when i think of GFPE i think of the system installed on large electrical equipment thats designed to shut off at a specific trip setting. either zero sequence gfpe or neutral bond gfpe. i dont know if the NEC wants us to install GFCI breakers on the feeders or if they want a real ground fault protection of equipment device installed on the main feeder. 555.3 says its required on the main feeder but if one shore power station messes up it will trip the entire panel. i am confused


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## electricalperson (Jan 11, 2008)

i found this link thanks too the IAEI. i need to renew my membership with them

http://www.iaei.org/magazine/?p=5217


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## hardworkingstiff (Jan 22, 2007)

electricalperson said:


> im sorry if what i say doesnt make sense. when i think of GFPE i think of the system installed on large electrical equipment thats designed to shut off at a specific trip setting. either zero sequence gfpe or neutral bond gfpe. i dont know if the NEC wants us to install GFCI breakers on the feeders or if they want a real ground fault protection of equipment device installed on the main feeder. 555.3 says its required on the main feeder but if one shore power station messes up it will trip the entire panel. i am confused



Seems to me, protection on either the main OR ALL branch feeders will satisfy the code.


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## hardworkingstiff (Jan 22, 2007)

I agree that putting the GFP on the main can be a very big pain in the old buttscola. I would much more prefer each branch feeder have it, that way the offending circuit can be ID'd immediately and you don't shut down the whole marina or portion of marina (let's say you have 5 different 800-amp panels).

This is really a good change, it's going to be very costly at 1st, but hopefully we get some competition and get prices down.


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## BBQ (Nov 16, 2010)

electricalperson said:


> im thinking the breaker probably already has GFPE built in with adjustable dials on the face of it?


We install many of those, but I have yet to see one that is adjustable down into the ma ranges,



electricalperson said:


> im sorry if what i say doesnt make sense. when i think of GFPE i think of the system installed on large electrical equipment thats designed to shut off at a specific trip setting. either zero sequence gfpe or neutral bond gfpe. i dont know if the NEC wants us to install GFCI breakers on the feeders or if they want a real ground fault protection of equipment device installed on the main feeder. 555.3 says its required on the main feeder but if one shore power station messes up it will trip the entire panel. i am confused


The NEC does not specify how to do it, only that it must be done. When I read your questions I pictured a unit like Hardworker posted. These type of units can shunt trip a breaker or a fused 'pringle switch'.

Some of our customers like fused pringle switches for the service disconnect and to comply with the required service GFP a device similar to the one Lou posted is used to shunt trip the pringle switch.


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## electricalperson (Jan 11, 2008)

hardworkingstiff said:


> I agree that putting the GFP on the main can be a very big pain in the old buttscola. I would much more prefer each branch feeder have it, that way the offending circuit can be ID'd immediately and you don't shut down the whole marina or portion of marina (let's say you have 5 different 800-amp panels).
> 
> This is really a good change, it's going to be very costly at 1st, but hopefully we get some competition and get prices down.


im thinking the way i would do it was put a GFCI breaker on each station. the design needs to be done right so we can try too eliminate nusance tripping. i think if we put one gfci breaker on the main panel feeding everything it would be very difficult too track down the problem and will cause headaches for everybody. a gfci breaker on every shore power station feeder too me is the best way it might cost more but will eliminate all the problems associated with the entire panel tripping at once. 

according too the IAEI article a ground fault monitor wired too a shunt trip breaker would work too. i think regular GFCI breakers would be best. low trip current and highest safety. if there is a high leakage though above 5 or 6mA then it would trip the gfci. the boats should be repaired when that happens since there is obviously a problem.


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## hardworkingstiff (Jan 22, 2007)

electricalperson said:


> im thinking the way i would do it was put a GFCI breaker on each station. the design needs to be done right so we can try too eliminate nusance tripping. i think if we put one gfci breaker on the main panel feeding everything it would be very difficult too track down the problem and will cause headaches for everybody. a gfci breaker on every shore power station feeder too me is the best way it might cost more but will eliminate all the problems associated with the entire panel tripping at once.
> 
> according too the IAEI article a ground fault monitor wired too a shunt trip breaker would work too. i think regular GFCI breakers would be best. low trip current and highest safety. if there is a high leakage though above 5 or 6mA then it would trip the gfci. the boats should be repaired when that happens since there is obviously a problem.


I tend to agree. I think I'm going to lose 80 pounds, and get certified in boat wiring. I think this could be the new "specialty" electrical work I'm going to get into. :thumbup:


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## BBQ (Nov 16, 2010)

electricalperson said:


> im thinking the way i would do it was put a GFCI breaker on each station.


I am sorry if this seems petty but stop calling it GFCI.

A GFCI is a specific type of device and not what we are talking about here.


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## hardworkingstiff (Jan 22, 2007)

BBQ said:


> I am sorry if this seems petty but stop calling it GFCI.
> 
> A GFCI is a specific type of device and not what we are talking about here.


I think he is talking about a GFCI breaker on the feeder going out on the dock. If you had a GFCI breaker on every branch feeder, it would meet the code, no?

I'm envisioning a MDP on shore, and all breakers that feed down to the dock are GFCI breakers.


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## electricalperson (Jan 11, 2008)

BBQ said:


> I am sorry if this seems petty but stop calling it GFCI.
> 
> A GFCI is a specific type of device and not what we are talking about here.


im calling it a GFCI breaker because im talking about ground fault circuit interrupting breakers. GFPE is ground fault protection of equipment


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## BBQ (Nov 16, 2010)

electricalperson said:


> im calling it a GFCI breaker because im talking about ground fault circuit interrupting breakers. GFPE is ground fault protection of equipment


I am not following you.

The NEC is not requiring GFCI protection of any of these feeders and IMO it would be a terrible idea to provide 'GFCI' protection of any feeder. The 5-6 ma trip level of a GFCI is far to low to be used for feeders. 

If it was my design it would get 99 ma GFP protection of each separate feeder.


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## BBQ (Nov 16, 2010)

hardworkingstiff said:


> I think he is talking about a GFCI breaker on the feeder going out on the dock. If you had a GFCI breaker on every branch feeder, it would meet the code, no?


It would

I also think it would be a horror show of tripped breakers and people ripping those breakers out. 



> I'm envisioning a MDP on shore, and all breakers that feed down to the dock are GFCI breakers.


I envision the same thing with 99-100 mA GFP instead of GFCI.


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## electricalperson (Jan 11, 2008)

BBQ said:


> It would
> 
> I also think it would be a horror show of tripped breakers and people ripping those breakers out.
> 
> ...


so the best way too do that would be to install shunt trip breakers with the GFPE device.


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## BBQ (Nov 16, 2010)

electricalperson said:


> so the best way too do that would be to install shunt trip breakers with the GFPE device.


Just guessing here that if the need arises the manufacturers will provide 100 mA GFP breakers.


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## hardworkingstiff (Jan 22, 2007)

*Meet code?*

Let's say you had 10 branch feeder breakers with GFP set at 90ma in a panel with a MB. 

Do you have to multiply the 90ma x the number of branch feeders to come up with 900ma which would exceed the 100ma limitation? :001_unsure:


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## electricalperson (Jan 11, 2008)

hardworkingstiff said:


> Let's say you had 10 branch feeder breakers with GFP set at 90ma in a panel with a MB.
> 
> Do you have to multiply the 90ma x the number of branch feeders to come up with 900ma which would exceed the 100ma limitation? :001_unsure:


what the code says is your main feeder to the marina can have 100ma protection. it also says if individual branch circuits or feeders have ground fault protection the main feeder isnt required to also have it


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## hardworkingstiff (Jan 22, 2007)

electricalperson said:


> what the code says is your main feeder to the marina can have 100ma protection. it also says if individual branch circuits or feeders have ground fault protection the main feeder isnt required to also have it


Right, but it didn't state what the GFP of the branch feeders should be. It does say the GFP on the main cannot exceed 100ma. So, if you had 100ma protection on 10 branch breakers your could have 900ma leakage at the main with no tripping and that would exceed the 100ma threshold. 

I was just wondering if the code panel discussed this and what their thoughts were.

Edit: I hope I'm not reading too much into this.


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## hardworkingstiff (Jan 22, 2007)

*Bump*

Bringing this thread back to life for selfish reasons. Next month NC adopts the 2011 code. There is starting to be a little bit of activity around marinas (very little, but still, hopeful). 

So, if anyone has already dealt with this GFP requirement, any experiences you can share would sure be appreciated.


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## hardworkingstiff (Jan 22, 2007)

Just making sure I have a handle on this. Typically the GFP we are talking about here would be accomplished by running the feeder conductors through a CT and then the CT would feed a signal to either a shunt trip on a breaker or some other device, right? If this is the basic concept then I have a concern.

If the service feeder conductors coming into the service disconnect go through the CT before the neutral makes connection to the GEC then wouldn't we more than likely get nuisance tripping from small amounts of current on the neutral caused by connecting it to the GEC?


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## brian john (Mar 11, 2007)

At a service the with Zero Sequence Ground Fault Protection all conductors are routed through the CT after the Neutral to Ground Bond. NO GROUNDS DOWNSTREAM of this CT.

For feeders you install the CT on all conductors phase and neutral, once again NO GROUNDS ON THE NEUTRAL downstream of this CT.

You need a CT designed for use with the GFP relay you will be utilizing. Typically the manufacture of the GFP relay sells a matching CT.

http://www.electromagnetic.biz/Portals/0/Docs/bgfl/bgfl.pdf


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## hardworkingstiff (Jan 22, 2007)

brian john said:


> NO GROUNDS DOWNSTREAM of this CT.
> 
> For feeders you install the CT on all conductors phase and neutral, once again NO GROUNDS ON THE NEUTRAL downstream of this CT.


OK, so what we need to do is to bring the feeders in, make a neutral to GEC connection, then through the CT.

All ground connection from the service connection to the shore power receptacles will be made outside of the protection of the GFP. Makes sense. Physically, I'm not sure how I would accomplish this. 

I've often brought 800-amp feeders to an I-Line panel (120/240) to power a dock. So, I guess I would have to bring in the neutrals and land them on a terminal block/bar bonded to the enclosure. Connect the GEC to this block (and I guess I would also bring the branch feeder grounds to this bar). Then I would pull the neutral from this bar and install them through the CT to an isolated neutral bar.


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## brian john (Mar 11, 2007)

You could use two CT’s one for the neutral and one for the phase conductors, just be sure to get the polarities right in terminating the CT secondaries.


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## hardworkingstiff (Jan 22, 2007)

Never mind.


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## chicken steve (Mar 22, 2011)

http://www.electromagnetic.biz/GROUNDFAULTDETECTION/tabid/55/Default.aspx

ashame they don't make a 480V model for the 277 heat tape install i'm doing.....

~CS~


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