Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-27-2018, 11:57 AM   #1
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Electrical issues, ground/neutrals and bonding

I'm going through hull zincs every month. Had new ones installed on November 22nd. Diver on January 13th says port hull zinc at or below 50% and starboard one at 75%. Had a good electrician out to inspect everything. Certified in Corrosion, etc. Well known "anal" guy. In fact the first thing he said when he got on the boat was "Did (guy who refered me to him) tell you how anal I am?" I said yes he did. Anyway, he went through the boat, anode overboard, checked bonding system. Electricity, marine or dirt, it NOT my forte to say the least. Trying to learn but from what I remember:

1. On the bonding, got .750 on the through hulls with .950 on the shaft. Said that was because I had zincs on the shifts. There was one through hull that was a bad reading but I don't remember what it was or the reading. I know I should have been writing all of this down but didn't.

2. Checked out the system in general and said I needed to have the ground/neutrals separated. I believe because power was bleeding back off the boat? He also said I needed galvanic isolators installed. Also said that my neighbors really appreciated having me here. I assume because they, or one of them, is using my zincs so to speak.

3. A new power cord as there was bleed through on one of them. Water intrusion or short somewhere. Power cords are fairly old.

Anyway, he quoted me $3K on the separating neutrals and grounds and $8K on redoing the bonding system. I'm going to have a second guy come out and do the same. Will take a pen or pencil with me this time In the mean time, does any of what I said make sense and do prices seem about what you guys would deem appropriate? I know I am REALLY vague on this but any comments appreciated even if they are along the lines of "Dude, go back and get specifics because we can't tell you a things from all of your nonsense"!!!
__________________
Advertisement

firstbase is offline   Reply With Quote
Old 01-27-2018, 12:25 PM   #2
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 2,659
Adding a galvanic isolator is simple if you can access the ground wire between the inlet and the electrical panel.

If you have 2 shore power inlets, the neutrals should not be comingled. With the new NEC that requires GFIs on docks, if your neutrals are comingled your boat will trip the GFI on the dock. My boat has 2 30 amp inlets and all the neutrals were on one bus bar. It took two of us a couple of days to split the neutrals and also replace the main electrical panel.

Redoing the bonding system is going to be a lot of grunt work just getting to everything and running the wire. Not very technical although. Just a lot of attention to detail.

Of the 3 tasks the only technically difficult one is seperating the neutrals. Doing the other 2 if you are good at DIY should not be above your ability. Maybe hire the electrician to oversee you doing the bonding if you want to save some money. Installing a galvanic isolator is very easy, just break the green inlet wires, put connectors on the wires and attach the connectors to the isolator.

Good luck.
__________________

Comodave is offline   Reply With Quote
Old 01-27-2018, 01:08 PM   #3
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Thanks Como. I have a 50amp connection on the bow and 30amp on the stern. I have not investigated where I could place the isolators but the stern of the GB 42' doesn't seem to be very friendly due to the 3 water tanks that run across the transom. I know that the isolators are supposed to be as close as possible to the connection. Not sure where the wiring runs after it leaves the connection but putting in a GI would seem to be forced to at least 6-10' away. Not sure though. Electrician told me exactly what you said. Bonding is grunt, dirty nasty work but not high tech. I could help if I wanted. I was just surprised at the $8K cost. On the grounds and neutrals...I am at a loss as I don't even know where they are much less how to deal with them. I'm looking at some learning course for marine electric as I really need to at least understand the basics. Not very intuitive to me! I get lost when I read that grounds and neutrals MUST be separated....EXCEPT....they are joined at one point. Huh? I believe ground goes back to ground...earth...water. Neutrals go back to the battery. I think. Maybe. If you are supposed to cross them at one point why the big deal when they are crossed elsewhere? As you can see....no real knowledge. I will keep reading.
firstbase is offline   Reply With Quote
Old 01-27-2018, 01:17 PM   #4
Guru
 
tiltrider1's Avatar
 
City: Seattle
Country: USA
Vessel Name: AZZURRA
Vessel Model: Ocean Alexander 54
Join Date: Aug 2017
Posts: 848
Yes what you said makes sense. I agree with comodaveís comments as well. You have become the the sacrificial anode for the entire marina. Your neighbors are all bragging about how they havenít needed to change their zincs all year. LOL.

As comodave said none of the tasks are particularly challenging technically but itís hard to estimate how much grunt time will be needed. I once separated grounds and neutrals on a boat, took me 10 minutes to separate the first 25 and 3 days to separate the last one.

8k for a new bonding system? Sounds like a lot but I donít know what is being specked out.
tiltrider1 is offline   Reply With Quote
Old 01-27-2018, 01:17 PM   #5
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 18,123
AC neutrals do NOT go back to the battery....neg DC goes back to all batteries and at one point joins bonding system and AC grounds.....

Keep reading....
psneeld is offline   Reply With Quote
Old 01-27-2018, 01:23 PM   #6
Guru
 
tiltrider1's Avatar
 
City: Seattle
Country: USA
Vessel Name: AZZURRA
Vessel Model: Ocean Alexander 54
Join Date: Aug 2017
Posts: 848
Grounds and neutrals are combined at the source of the power. This means if your power comes from shore then they are combined at the shore source, not on your boat. When you are on generator they are combined at the generator. That’s why they are sometimes separated and sometimes not.

A good marine inverter automatically combines and separates the ground and neutral.
tiltrider1 is offline   Reply With Quote
Old 01-27-2018, 01:23 PM   #7
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
I actually knew that it is neg DC that goes back to battery but I will still continue reading! Maybe throw in a book about how to communicate clearly.

Electician told me that the firs task is the neutral/grounds. Bonding could come later. He seemed like he didn't think it a big issue. Basically my ribbon system is just tired and old after 30 years, possibly connection/conductivity issues.

I do not understand how I am the community zinc. Because I am allowing ... never mind. I won't even try!
firstbase is offline   Reply With Quote
Old 01-27-2018, 01:28 PM   #8
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Quote:
Originally Posted by tiltrider1 View Post
Grounds and neutrals are combined at the source of the power. This means if your power comes from shore then they are combined at the shore source, not on your boat. When you are on generator they are combined at the generator. Thatís why they are sometimes separated and sometimes not.

A good marine inverter automatically combines and separates the ground and neutral.
I have an inverter installed.
firstbase is offline   Reply With Quote
Old 01-27-2018, 01:29 PM   #9
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 7,263
Each boat is different as far as access and $$ if you want to redo your grounding systems. Last fall mine was redone for about 2K by a real pro. But, I was not going through zincs like you.

For the money they quoted you suggest an isolation transformer or two be evaluated. Victron has some new design ITs out that may be worth a look. Your marine electrician should immediately know about Victron's offerings.

Also, suggest a redesign of your grounding system must be done where there is a new design GFIC 30 ma pedestal or a test plug in arrangement. Without this your efforts to redo the grounding system may be for naught. Eliminating the 30 ma trip is an ultimate goal IMHO. A proper (there are indeed wrong ways) redo of the bonding system should fix this. Does your vessel presently trip a 30 ma GFIC dock pedestal?
sunchaser is offline   Reply With Quote
Old 01-27-2018, 01:32 PM   #10
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Quote:
Originally Posted by sunchaser View Post
Each boat is different as far as access and $$ if you want to redo your grounding systems. Last fall mine was redone for about 2K by a real pro. But, I was not going through zincs like you.

For the money they quoted you suggest an isolation transformer or two be evaluated. Victron has some new design ITs out that may be worth a look. Your marine electrician should immediately know about Victron's offerings.

Also, suggest a redesign of your grounding system must be done where there is a new design GFIC 30 ma pedestal or a test plug in arrangement. Without this your efforts to redo the grounding system may be for naught. Eliminating the 30 ma trip is an ultimate goal IMHO. A proper (there are indeed wrong ways) redo of the bonding system should fix this. Does your vessel presently trip a 30 ma GFIC dock pedestal?
In the slip I am always on 50amp. Not tripping anything. The only time I hooked up to 30amp was when I was hauled for a bottom job. No tripping then.
firstbase is offline   Reply With Quote
Old 01-27-2018, 01:36 PM   #11
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,104
Form what you have said, your guy seems knowledgeable and honest in his assessment and description of the work. So that's a good start. His work may be expensive, but if he knows what he's going and fixes it correctly the first time around, it may well be money well spent. The alternative always seems to be paying two idiots twice to not fix the problem.
__________________
www.MVTanglewood.com
twistedtree is offline   Reply With Quote
Old 01-27-2018, 01:50 PM   #12
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Thanks. I don't like a lack of basic knowledge of things and am ok with spending some money to get it. What threw me off was that I called the guy to a) fix a bilge pump (pump works fine but not getting power to it for some reason. Tried to trace the wiring back as far as I could but it goes into the panel and ...I got lost from there). and b) take a look at whatever is eating my zincs. We never got to the bilge pump and I wasn't expected $3K and $8K for anything so it all came as a big surprise. Sort of floored by that a little bit. But...its a boat and that what happens. I want to have a second guy some and do the same as well as fix my bilge pump. this time I will pay more attention to the exacts on the bonding and the grounds/neutrals. I have to solve the issue so will most likely call the original guy back to do the gorunds/neutrals. I'm not sure if the $3K included the isolators or not. I don't think it does.
firstbase is offline   Reply With Quote
Old 01-27-2018, 01:54 PM   #13
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Also, on the zincs, the bonding system has nothing to do with why my zincs are getting eaten correct?
firstbase is offline   Reply With Quote
Old 01-27-2018, 02:07 PM   #14
Guru
 
twistedtree's Avatar
 
City: Gloucester, MA
Country: USA
Join Date: Jan 2013
Posts: 4,104
Quote:
Originally Posted by firstbase View Post
Also, on the zincs, the bonding system has nothing to do with why my zincs are getting eaten correct?
Depending on what he's including in the "bonding system", it probably does. But it sounds like you are unclear what each piece of work includes, so I think it would be good to get that clarified.

I missed the part about your bilge pump, and that now makes me wonder about the guy. Also the lack of clarity around what each piece of work involves and what might be extra.
__________________
www.MVTanglewood.com
twistedtree is offline   Reply With Quote
Old 01-27-2018, 02:32 PM   #15
Guru
 
firstbase's Avatar
 
City: Jupiter, Florida
Country: United States
Vessel Name: Black Eyed Susan
Vessel Model: Grand Banks 42' Classic
Join Date: Nov 2016
Posts: 1,062
Lack of clarity is my first name when it comes to electrical. A little better on land...on land it's my middle name. This particular guy works on huge boats, restorations, mega yachts. I sort of got the feeling that looking at my bilge pump was a little beneath him. Plus I think he got pissed off at me when one of my bilge flooring grates, cut too narrow by the PO, slipped off one side and when it went down to the bilge floor caused him to scrape a knee. I have since fixed that issue. Sure wish there was an online class on marine electrical. I have the known books. Just get lost pretty quickly. The other problem I have is that tracing wires and systems in my boat is just a pain and hard to do. Big news to everyone in here right??
firstbase is offline   Reply With Quote
Old 01-27-2018, 02:51 PM   #16
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 7,263
Quote:
Originally Posted by firstbase View Post
In the slip I am always on 50amp. Not tripping anything. The only time I hooked up to 30amp was when I was hauled for a bottom job. No tripping then.
Not 30 amp. 30 milliamp. 30ma is the stray current trip point for the newer GFIC dock pedestals. A decent marine electrician can fill you in on this new dock code design and also tell you how he would test on an ongoing basis as new grounding system is installed to insure a re-do of the bonding system would eliminate that issue.
sunchaser is offline   Reply With Quote
Old 01-27-2018, 05:16 PM   #17
Guru
 
Comodave's Avatar
 
City: Au Gres, MI
Country: US
Vessel Name: Never Say Never
Vessel Model: President 41 DC
Join Date: Jul 2015
Posts: 2,659
If your neutrals are comingled, it will trip the dock GFI. The probable reason you are not tripping the dock GFI now is that most docks do not have GFIs yet. The change to dock GFIs came from a new NEC in 2011. Docks are just now (within the last year or two) converting to GFIs. As time goes by, more and more docks will have GFIs so getting the problem fixed, even if you are not experiencing a problem at your dock, is very important unless you plan on never plugging into another dock. If a marina does any substantial electrical work they will be required to upgrade to GFIs. Florida is a prime example due to the hurricane damage, almost any dock that had damage will most likely convert to GFIs.
Comodave is offline   Reply With Quote
Old 01-27-2018, 05:33 PM   #18
Guru
 
High Wire's Avatar
 
City: Cape May, NJ and Englewood, FL
Country: USA
Vessel Name: Irish Lady
Join Date: Dec 2007
Posts: 2,377
I wonder if the bad bilge pump and the zincs problem are tied together. If the bilge pump itself has water in the casing or the wire insulation is cracked and submerged, that could cause some stray current corrosion.

Take a look at Jims tests:
https://gilwellbear.wordpress.com/ca...sts-for-boats/

Certainly not for everyone.
__________________
Archie
1984 Monk 36 Hull #46
Englewood, FL and Cape May, NJ
High Wire is offline   Reply With Quote
Old 01-27-2018, 07:12 PM   #19
Guru
 
City: Fairport
Country: United States
Join Date: Jan 2017
Posts: 1,144
A docked boat can sink quite a bit of ground current thru the u/w metal parts from the dock electrical ground. You don't even need the breaker turned on.
I would measure the ground current somewhere in the line; down to mA.
If there is much of that, then the isolator has merit.

If the ground current is high ONLY when the L and N are breakered on, then that points to some leakage from something that has power. there will be a GFCI trip soon (if a modern dock) or there will be zincs lost.

The DC story would go differently. There, some low level fault from something like a bilge pump from +12V through bilge salt water could cause some bad things to happen, especially if the bonding circuit was not well connected to DC-.
diver dave is online now   Reply With Quote
Old 01-27-2018, 08:01 PM   #20
Guru
 
Lou_tribal's Avatar
 
City: Quebec
Country: Canada
Vessel Name: Bleuvet
Vessel Model: Custom Built
Join Date: Jan 2016
Posts: 3,016
8000$ to redo your bonding??? What is the size of your boat?

L
__________________

Lou_tribal is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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





All times are GMT -5. The time now is 02:34 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012