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Old 31-12-2011, 12:27   #91
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Quote:
Originally Posted by Ram
I have a question for those who may know- first in my experience I have never had this problem with zincs or metal corroding, the boat is now almost 6 years old and my original sail drive zincs are in very good shape, could it be that because I’m almost never plugged in to an AC outlet that I don’t experience this sort of problem??
Yes. Absolutely.
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Old 31-12-2011, 12:39   #92
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Re: Neighbor dumping raw AC into water?...what to do?

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Originally Posted by brankin View Post
1: I do not have any type of isolator. I am in salt water so do I want a galvanic isolator or isolation transformer? Which will give me the best protection and which is the most rugged brand?
Definitely an isolation transformer. Victron is very good.

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2: I have two 30 amp panels in my boat with two exterior connectors. Can I wire both neutrals into one isolator or do I need two isolators. Is the amperage rating for the galvanic isolator need to be the same as the shore power ie 30 amp for 30 amp shore power. 60 amp for two 30 amp shore power cables.
There are 2 options:

1. Install two 3.6kW isolation transformers and keep everything else the same.
2. Install 120/240 components: single 120/240V 50A shore power cord connecting to a 7kW isolation transformer, connecting to a (small&cheap) autotransformer. That last one will create a new neutral and give you the two 120V feeds again in addition to a 240V feed. This last option is the best and cost might not be much more but it's more work to install.

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3: During my latest survey, I was told to have all my tru-hulls grounded which I do. What is the requirement or set of rules that the insurance companies require you to follow. I don't want to have a loss and then be turned down because I was out of spec.
Check this with somebody else because I am not sure. Grounding thru-hulls is more part of bonding and protection during lightning strikes.

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4: I have searched the forum for a tread which will address the exact technique for trouble shooting AC/DC power leaks. Can someone post a link that will explain the procedure from A to Z?
If you do the following three things, you eliminate 99.999% of all possible causes:
1. Install isolation transformer
2. Make sure that the anchor chain, when anchored, is NOT connected to boat ground. This means not grounding windlass, bow roller or any other hardware that touches the chain.
3. Maintain zinc nodes.

If you want to check often instead of taking these precautions, you need special equipment, which can even be installed permanently and generate alarms in case of trouble. Aluminium boats often have that.

ciao!
Nick.
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Old 31-12-2011, 12:45   #93
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Re: Neighbor dumping raw AC into water?...what to do?

stuff happens. electrical current strays especially when grounds are faulty. check yours. make sure your boat is perfect before accusing others of dumping any kind of anything. make your zincs fresh as needed.
relocate if it bothers ye.
court????? roflmfao. sorry--- ye wont get it on the schedule.
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Old 31-12-2011, 13:18   #94
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Re: Neighbor dumping raw AC into water?...what to do?

I did the AC clampon test on our dock everyone was clean--no net AC current flowing. The next dock (which has a reputation for burning up zincs) was a different story. About a third of the docks had measurable AC leaking into the water--up to 200 milliamps. No wonder there are dead birds floating by all the time.

Going from AC leakage to DC leakage is a different story and more complicated, but the AC clampon test looks like it is an easy way to find problem boats. In the smarter side of the pond, those boats wouldn't be a problem because they would have tripped the dock RCD's.
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Old 31-12-2011, 13:58   #95
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Re: Neighbor dumping raw AC into water?...what to do?

It would be interesting if the OP were to move to another marina and encounter the same problem with a new neighbor. Better to install the GI and be done with the problem regardless of location.
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Old 31-12-2011, 14:02   #96
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Re: Neighbor dumping raw AC into water?...what to do?

The way I see it.
RCD's, ELCB's,GXYZ's means wiring upgrade because of exactly what is happening here. Or they would be forever tripping. eg 15mA leakage current for 30mSec.
That is why pumps,fridges & dishwashers are exempt here. Some leak ac from new.Also I beleive the US doesn't have the MNE (multiple neutral earth) system in alot of places. Hence Residual current devices are not relevant
as earth shouldn't have a polarity. Situatiion could get confusing .

Clamp meters a go for sure. Current in = current out; if it doesn't its leaking back to the grid somewhere thru fault/ low resist path. Saltwater has a penchant to rectify-bingo. Hell your boat is sitting in electrolyte.
The no brainer is to isolate but you could play roulette with marina polarity
if you like living on the edge.
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Old 31-12-2011, 14:11   #97
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Re: Neighbor dumping raw AC into water?...what to do?

Big fan of ditching the thru hull bonding. Isolate the grounds for dc and ac. use a clean path for lightening protection. 3 different beasts keep them isoloted as well as you can
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Old 31-12-2011, 14:30   #98
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Re: Neighbor dumping raw AC into water?...what to do?

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Originally Posted by vintageray View Post
It would be interesting if the OP were to move to another marina and encounter the same problem with a new neighbor. Better to install the GI and be done with the problem regardless of location.
That's what we were trying to get him to realize. Protect your boat, period. I've heard of a case where the offending current was coming from a marina across a fairly wide creek. If you took care that your boat was protected, fine. If not, well, some folks who never came to see or check on their boats had a heck of a mess waiting for them. And what of when one goes for a weekend or several week excursion to transient slips when on a vacation cruise? How does one insure those marinas and all their tenants are "safe" to be around? Like some have said.... you MUST take your own boat out of the stray current connection
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Old 31-12-2011, 14:32   #99
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Re: Neighbor dumping raw AC into water?...what to do?

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Big fan of ditching the thru hull bonding. Isolate the grounds for dc and ac. use a clean path for lightening protection. 3 different beasts keep them isoloted as well as you can
I can relate to that.
What about thruhulls for a economical ground plane?
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Old 31-12-2011, 14:39   #100
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Re: Neighbor dumping raw AC into water?...what to do?

If you are connecting thru hulls for the ground plane you are bonding them. Keep it sepertate and use copper tape or a ground plane plate.
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Old 31-12-2011, 14:41   #101
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Re: Neighbor dumping raw AC into water?...what to do?

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Big fan of ditching the thru hull bonding. Isolate the grounds for dc and ac. use a clean path for lightening protection. 3 different beasts keep them isoloted as well as you can
This makes sense to me. That's the way I have it -- and isolated propshaft too. But we rarely plug into marinas.
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Old 31-12-2011, 14:42   #102
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Re: Neighbor dumping raw AC into water?...what to do?

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I know the OP is looking for the root cause, but my zinc problems went away when I installed solar panels and disconnected all shore connections. The zincs still need to be replaced from time to time, but much less often now.

I did put a clamp-on DC ammeter over my shore-power cable, taking several turns through the ammeter's jaws to increase the sensitivity. I have no isolation transformer, nor blocking diodes, and there was a measurable DC current through the power cable. I never bothered to track it down, since the solar panels took care of it.

Hanging one of those zinc "fish" over the side (or any kind of zinc, properly connected to your boat's ground system) will also help save your regular zincs. The clamp-on ammeter also showed DC current running through the zinc's connecting wire when I had the shore-power plugged in. It is possible to "over-zinc", but that wasn't a problem in my case.

If the marina or a neighboring boat has a serious electrical leakage or grounding problem it should be addressed for everyone's sake, but you're going to have a very hard time achieving a completely stray-current-free environment -- there are just too many possible sources. I think the best solution is to isolate your boat (transformer, diodes, solar, etc) and that way you are well-protected against even the "normal" level of stray marina current.
I would wonder what would happen if the OP unplugged his power cable.

Electricity wants to take the easiest path to ground, and if that is through his ground, that is the way it will go.

I would vote for isolating your wiring first, seeing if you can't run more on solar power second, then third figuring out if there is some easy fix for another boat. Maybe print up some nice West Marine catalog descriptions of different components and leave them around that would solve the problem, and address why it is a good thing to solve. (see if there are any legal cases claiming negligence for other boat owners who have electrocuted people in the water)
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Old 31-12-2011, 14:43   #103
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Re: Neighbor dumping raw AC into water?...what to do?

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Hey guys, I think we are just talking to air (looks around in cyberspace) I don't see the OP anywhere...
Maybe he just got mad and stomped off. Or,
Maybe he just had an agenda and when we didn't match it, he found a more sympathetic group- maybe a lawyers group

For what its worth, I learned something today.
LMAO! The OP realized the severity of said problem, launched and was SHOCKED to find out that electricity travels. ? Because apparently no one in here gave any sound advice.

Also I too would like to know where one can obtain a $2.00 lawyer.
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Old 31-12-2011, 14:44   #104
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Re: Neighbor dumping raw AC into water?...what to do?

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Originally Posted by sabray View Post
If you are connecting thru hulls for the ground plane you are bonding them. Keep it sepertate and use copper tape or a ground plane plate.
And have a quick disconnect lug on the Cu tape for electrical storms?
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Old 31-12-2011, 14:47   #105
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Quote:
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LMAO! The OP realized the severity of said problem, launched and was SHOCKED to find out that electricity travels. ? Because apparently no one in here gave any sound advice.

Also I too would like to know where one can obtain a $2.00 lawyer.
The $2 lawyer is in the yellow pages right under free legal advice on the internet.
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