Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 15-07-2011, 07:15   #16
Registered User

Join Date: Apr 2010
Location: Newport News VA
Boat: Egg Harbor sedan cruiser 1970
Posts: 829
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
I'm missing something. How does the ABYC solution subject boats to electrolysis more than other solutions?
I know GFCI the ground is NOT NEEDED AT ALL. It is unnecessary and just an extra wire. These devices measure current going in and current going out, so if they leak anywhere, then they turn off the power.
The ground wires on boats is where the galvanic currents are conducted (hence galvanic isolators are used), With an ELCI or GFCI ground wires likely dont not to be hooked up or even exist at all.
Any current leakage outside of that wire will turn off the power to that wire.

The purpose of the ground wire is to conduct ground faults away with its lower resistance from conducting too much elsewhere which has a higher resistance. High ground wire resistance makes the ground wire less effective and current can leak away from that ground and maybe through you. Only benefit left for the ground is if the GFCI or ELCI fails in a conducting mode, then it still has a purpose.

So why not deal with it intelligently controlling the power flow using GFCI or ELCI breakers? Which if any power faults are detected will shut off the power.
__________________

__________________
sdowney717 is offline   Reply With Quote
Old 15-07-2011, 09:04   #17
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,424
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by sdowney717 View Post
I know GFCI the ground is NOT NEEDED AT ALL. It is unnecessary and just an extra wire. These devices measure current going in and current going out, so if they leak anywhere, then they turn off the power.
The ground wires on boats is where the galvanic currents are conducted (hence galvanic isolators are used), With an ELCI or GFCI ground wires likely dont not to be hooked up or even exist at all.
Any current leakage outside of that wire will turn off the power to that wire.

The purpose of the ground wire is to conduct ground faults away with its lower resistance from conducting too much elsewhere which has a higher resistance. High ground wire resistance makes the ground wire less effective and current can leak away from that ground and maybe through you. Only benefit left for the ground is if the GFCI or ELCI fails in a conducting mode, then it still has a purpose.

So why not deal with it intelligently controlling the power flow using GFCI or ELCI breakers? Which if any power faults are detected will shut off the power.
OK, but my question is, in areas where ELCI/RCBO/GFCIs are installed in power pedestals, does the code allow for NOT connecting the ground wire to the boat?

I haven't thought thru all the implications, just trying to understand the various codes.
__________________

__________________
DotDun is offline   Reply With Quote
Old 15-07-2011, 10:08   #18
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,573
Images: 240
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by DotDun View Post
OK, but my question is, in areas where ELCI/RCBO/GFCIs are installed in power pedestals, does the code allow for NOT connecting the ground wire to the boat?
No.
When the boat is connected to shore power, the boat's AC system is bonded through the grounding conductor back to a grounding electrode on shore. As long as the shore-to-boat grounding connection is solid, any ground-fault current will travel back to shore and trip the circuit's overcurrent protection. However, if the shore-to-boat grounding connection is severed, or even slightly weakened, fault current will travel through a parallel path created by the bonded AC/DC ground connection on the boat. Stray current then travels through the water in an attempt to reach shore, and the shore power grounding electrode.
In many cases, this parallel path is weak, as the voltage decreases with distance away from the boat. The current may not be sufficient to trip the shore overcurrent protection, and the fault will continue indefinitely.
That is why a strong, continuous grounding path back to shore is imperative.

Quote:
Shore Power Pedestals - Will They Ever Be ELCI Breakered ?
Yes.
See ➥ Ground-Fault Protection for Marinas and Boatyards | IAEI Magazine

NEC Article 555
Marinas and Boatyards 555.3 Ground Fault Protection.
The main over current protective device which feeds the marina shall have ground fault protection not exceeding 100mA. Ground fault protection of each individual branch or feeder circuit shall be permitted as a suitable alternative.

Interpretation of Requirement:
Ground fault protection must be provided at one of the following locations:
a) on the main circuit breaker for distribution equipment supplying power in the marina
or
b) on any feeder or branch circuits providing power to pedestals in a marina
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-07-2011, 10:28   #19
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by DotDun View Post
OK, but my question is, in areas where ELCI/RCBO/GFCIs are installed in power pedestals, does the code allow for NOT connecting the ground wire to the boat?

I haven't thought thru all the implications, just trying to understand the various codes.
The ISO permit the ground wire not to be connected on a boat with a RCD (so a lot of European boats are wired this way). ABYC does not unfortunately allow this exception.
__________________
noelex 77 is offline   Reply With Quote
Old 15-07-2011, 10:34   #20
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,573
Images: 240
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by noelex 77 View Post
The ISO permit the ground wire not to be connected on a boat with a RCD (so a lot of European boats are wired this way). ABYC does not unfortunately allow this exception.
What's unfortunate about not allowing the UNSAFE elimination of a safety grounding conductor?
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-07-2011, 10:46   #21
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,424
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by noelex 77 View Post
The ISO permit the ground wire not to be connected on a boat with a RCD (so a lot of European boats are wired this way). ABYC does not unfortunately allow this exception.
RCD in the pedestal or boat?
__________________
DotDun is offline   Reply With Quote
Old 15-07-2011, 11:19   #22
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by GordMay View Post
What's unfortunate about not allowing the UNSAFE elimination of a safety grounding conductor?
I do not believe it is unsafe.
The only significant danger is if the RCD stops working and it needs to fail in the conductive mode (and there needs to an electrical fault as well). RCDs are easily tested.

Note I if you do not agree there is nothing to stop you adding a grounding system to an International standards organization approved installation, but the ABYC forbids you changing your boat to conform with the ISO standards.
It also insists you modify imported boats that already meet a carefully designed standard.
There are far more beneficial ways, that do not increase your risk of corrosion problems, to spend safety dollars IMHO.
__________________
noelex 77 is offline   Reply With Quote
Old 15-07-2011, 11:20   #23
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by DotDun View Post
RCD in the pedestal or boat?
Boat and pedestal I think is the correct answer, but I am not sure. Its easy and prudent to add a RCD to shore power if there is not one fitted at the Pedestal.
__________________
noelex 77 is offline   Reply With Quote
Old 15-07-2011, 11:43   #24
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
iSO standards require three wire mains wiring throughout the boat and from the pedestal. What they do allow is that you need not bond DC negative and mains earth if you have a whole boat RCBO fitted. This is different to ABYC

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 15-07-2011, 11:52   #25
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,573
Images: 240
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

I don’t see where the ISO permits the ground wire not to be connected on a boat with a RCD.
I do see that they don’t require the AC ground to be bonded to the DC Negative.

Excerpted from ISO 13297
Small craft - Electrical systems - Alternating current installations

"4.2 The protective conductor shall be connected to the craft's d.c. negative ground (earth) as close as practicable to the battery (d.c.) negative terminal.

NOTE If an RCD (whole-craft residual current device) or an isolation transformer is installed in the main supply circuit of the a.c. system (see 8.2), the negative ground terminal of the d.c. system need not be connected to the a.c. shore ground (protective conductor).

13.4 Receptacles/sockets shall be of the earthing type with a terminal provided for the protective conductor."
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-07-2011, 12:07   #26
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Thanks to Goboatingnow and Gord May for clarifying I should have said the AC to DC ground connection. Sorry if this caused confusion
__________________
noelex 77 is offline   Reply With Quote
Old 15-07-2011, 12:21   #27
Registered User

Join Date: Apr 2010
Location: Newport News VA
Boat: Egg Harbor sedan cruiser 1970
Posts: 829
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

not advocating to get rid of the safety ground, just want to see GFCI at the marina.
I am happy to see the NEC is doing something about this.
Still like the article says, 100 ma is not going to keep you from dieing.

What benefit is the device if you still end up dead. Considering the article says children are most susceptible and they are most likely to go in the water.
__________________
sdowney717 is offline   Reply With Quote
Old 15-07-2011, 12:22   #28
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,424
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by noelex 77 View Post
Thanks to Goboatingnow and Gord May for clarifying I should have said the AC to DC ground connection. Sorry if this caused confusion
Yes! Goboatingnow & Gord, thanks for clearing that up! I worried that people were either not connecting the safety ground to their appliances/receps or connecting boat ground and shore ground together downstream of the ELCI (or doing both).
__________________
DotDun is offline   Reply With Quote
Old 15-07-2011, 12:24   #29
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Professional Boatbuilder had a very good article on ground fault protection. written by Nigel Calder
In the April/ May 2006 edition.
__________________
noelex 77 is offline   Reply With Quote
Old 15-07-2011, 12:26   #30
Registered User

Join Date: Jun 2007
Location: SW Florida
Boat: FP Belize, 43' - Dot Dun
Posts: 3,424
Re: Shore Power Pedestals - Will They Ever Be ELCI Breakered ?

Quote:
Originally Posted by noelex 77 View Post
The only significant danger is if the RCD stops working and it needs to fail in the conductive mode (and there needs to an electrical fault as well). RCDs are easily tested.
One fault that renders ELCI non-operative is when they require power to open the circuits and then the neutral goes open ahead of the ELCI. You still have hot connected with no leakage protection. This situation can be dangerous.
__________________

__________________
DotDun is offline   Reply With Quote
Reply

Tags
shore power

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Shore Power Cords MML Electrical: Batteries, Generators & Solar 8 30-08-2011 00:34
ABYC Power Feeder Code E-8.11.4.1 vs E-8.11.9.2.1 sdowney717 Electrical: Batteries, Generators & Solar 27 09-07-2011 10:47
Electrical Layout Advice / Opinions Required simonmd Electrical: Batteries, Generators & Solar 8 03-07-2011 09:30
For Sale: Marinco Pigtail Shore Power Adapter Greg S Classifieds Archive 1 01-07-2011 10:36



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 00:34.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.