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Wow. I have learned a lot from you guys! Thanks, and for the insights and the diagram. The marine certified electrician will be here today to test the system.

Just to clarify - the boat is new. Shore power on board is by Chaparral. When I said electrician installed the shore power, I meant at the new dock. Also, the GFI is 5 milliamperes threshold and it all way up at the house, where the power is connected to a new panel. That is where I test the GFI, and when I do, all power to the dock is terminated. Once terminated, only way to test for current on the props is get in the water and touch the props. We'll try that today, I imagine. IF there is still current, then it's the boat.

Will advise, and thanks again!

 

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I found this on the internet about galvanic isolators. I didn't' know what they are. This is informative for me, so I thought I'd share it. Enjoy!

"A galvanic isolator is a device used to block low voltage DC currents coming on board your boat on the shore power ground wire.  These currents could cause corrosion to your underwater metals; through hulls, propeller, shaft etc.

Boats in a marina plugged into shore power all act as a giant battery.  They are all connected together by the green shore power ground wire, which is (or should be) connected to their DC grounds, engine block, and bonded underwater metals.  If the boats are in salt water then that forms an electrolyte and the dissimilar metals connected together act as a battery, causing corrosion.

The galvanic isolator has two pairs of diodes set up so that a voltage of about 1.2 volts is required to cause them to conduct.  As most DC voltages caused by galvanic action will be less than this, they are blocked. Good quality isolators also contain a capacitor, which only conducts AC current, as a backup.

Normally no AC current is carried on the shore power ground wire, but it has to be able to carry the full load of the circuit in the event of a fault.  Therefore it is important to have a good quality unit that will not overheat when required to carry the rated load.  Some heat will be generated by the voltage drop and the unit must be able to withstand this."

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Please DO NOT get into that water again.................. YOU ARE NOT A   super / indefinite lucky electrocution test device.......... Call the marine Electrician and tell him you want to go testing the prop again.

If he is any good ?  He will tell you NOT TO DO IT.    The leakage voltage could go to 120 vac.  You will drown in front of him. Just like many people still do as posted by Iggy.

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Yes, the electrician said the GFI at main panel protects entire dock, and even if we have flooding at house the 5mA GFI will trip. It has never tripped.

Yes, there is a small electrical panel at the dock with four circuits breakers (2 20A and 2 30A). We have shore power (30A), one electrical outlet, and a circuit for lighting.

And, color me silly, but I am NOT getting in the water to test for current. If fact, yesterday, it was my neighbor who felt the current while we were re-positioning boat on the lift. I won't ask him to go in again and test it! :-) 

 

Also, is a galvanic isolator something that is installed on the boat by Chaparral?  Or, is that a device installed when shore power is run to the dock and installed by the electrician?

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Great to hear the electrician is scheduled today.  Yesterday's feedback from the electrician and dealer was irresponsible.

A test the electrician should conduct is to take a clamp style meter and measure voltage on each of the 4 circuits at the dock (one at a time).  You'll need proper extension cords to do this because this is what you clamp around, and I assume the two 30 amp shore power circuits use the correct receptacle which is different than a standard 120 volt outlet.  Voltage should be zero on each of the circuits.  If there is any reading, there's a problem and stray voltage is entering the system from somewhere.  What the hot supplies, the neutral conveys back.  They sum to zero.  The principal difference between "land" and boat wiring is the how negative and ground sides are handled. A 120 volt "land" circuit has a hot, neutral and ground.  The ground handles any fault.  In most jurisdictions (not all), it's allowable intermix neutral and ground on the same bus within the panel.  It's not allowed at the receptacle.  A 240 circuit follows the same rule, except there are two hot leads.  In a boat, all metal parts are bonded and separate from the negative.  Your problem seems isolated to your boat.  If stray AC was in the water from your set-up, the island or a neighbor's dock, it would have been felt without touching the drive and it would have been more of a stun and potentially debilitating (overall weakness, weak in the knees, short of breath, felt in the heart, partial or full collapse, weakness or not being able to speaking, partial or full inability to control motor function, etc.).  I am in no way guaranteeing it's not coming from something else.  I'm not there and unable to view what you can.  But, based on the descriptions posted to this point, it points this direction.  I do hope this is figured out.  

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6 hours ago, docdixon said:

Yes, the electrician said the GFI at main panel protects entire dock, and even if we have flooding at house the 5mA GFI will trip. It has never tripped.

Yes, there is a small electrical panel at the dock with four circuits breakers (2 20A and 2 30A). We have shore power (30A), one electrical outlet, and a circuit for lighting.

And, color me silly, but I am NOT getting in the water to test for current. If fact, yesterday, it was my neighbor who felt the current while we were re-positioning boat on the lift. I won't ask him to go in again and test it! :-) 

 

Also, is a galvanic isolator something that is installed on the boat by Chaparral?  Or, is that a device installed when shore power is run to the dock and installed by the electrician?

My understanding that the GFI breaker for each outlet, new laws, needs to be at the power station.

Also, is a galvanic isolator something that is installed on the boat by Chaparral? -- YES it is

 

 

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Thank you. Very useful info.

Something I read at Kennedy Yacht  Services about Marine electric systems indicated the galvanic isolator could be defective and they suggested ways to test it. Apparently testing is difficult. Replacement is expensive. 

Anyone know where in engine compartment the galvanic isolator is located in a Chap Sig270?

man oh man. This is lots more involved than I’d ever have imagined. 

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1 hour ago, docdixon said:

Thank you. Very useful info.

Something I read at Kennedy Yacht  Services about Marine electric systems indicated the galvanic isolator could be defective and they suggested ways to test it. Apparently testing is difficult. Replacement is expensive. 

Anyone know where in engine compartment the galvanic isolator is located in a Chap Sig270?

man oh man. This is lots more involved than I’d ever have imagined. 

No, testing is very easy. You just need a Ohms meter

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4 hours ago, Hatem said:

Not reading that entire mess of new code interpretations for shore power and marinas or whatever.  Who the heII wants to go through that painful mess?

And in what ways was anything that was said wrong or right?  Clopudus can speak for himself but I'm not sure what you're getting at.  So what are you trying to say, exactly?  That the way the electrician has the entire dock and lift on a single MAIN GFI breaker on the main panel in the house is not enough, and that the 4 circuits at what you call the "power station" need to all be on their own, individual GFI breakers?  If that's what you're getting at, tell Joe to tell his electrician lol.  Not sure what that has to do with me.  And what's the power station?  You mean the sub-panel at the dock? 

Not getting into it..............

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  • 1 month later...

Update to all who offered information and help.

 

Recently, my neighbor took his sailboat to the yard for a bottom job. Guess what, no more current on my prop!

His boat was the source, not mine. Fortunately, he has now sold his boat and it will be removed next week. Meanwhile, my boat is high and dry. 

 

For the curious, his sailboat is wet slipped and is about 100' from mine. My boat is usually stored on my covered lift high and dry.

My last boat, an IP27, was wet slipped and the marina had several devices that kept stray current to a minimum and if they ever discover a boat that was 'leaking' current, that boat had to be moved and/or repaired. The marina actually took periodic readings in the water. Very helpful.

 

Thanks again for all the useful commentary and advice.

Fair weather,

Joe

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8 hours ago, Hatem said:

Good riddance!  The bottom paint basically insulated the bad ground he had on his sailboat?  That's actually pretty strange.  I hope he knows that there is something wrong with his boat.  Didn't think bottom paint was much of an insulator but I suppose if the voltage is low enough, it could happen.  That was not a good situation especially forcing your electrician to come up with that theory that there are so many transformers grounded in that area causing the stray current into the lake area is really too bad, since that is highly unlikely and merely an impossibility TBPH, but maybe he felt he couldn't just say "I don't know what it is, but it isn't my work."  Good thing.  Just watch out for the next person who moves in there.

The bottom paint was no way a insulator. It was his bonding system then that was putting current into the water. 

To docdixion, your two boats where ether very close to each other or your in deep water. His bonding system was putting current into the water. When you touched your prop, it is grounded so you felt it. Know i would check your anodes. I would think there eaten up by this.

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5 hours ago, Hatem said:

Why are you saying it wasn't an insulator?  Apparently it did exactly that.  If it stopped once the guy had his bottom painted, it insulated whatever electrical current that was being emitted by the sailboat and kept it from getting into the water and being conducted by the OP (or his friend) touching his own props while standing in the water.

Unless it happens to be an amazing coincidence that the stray current disappeared the same day the sailboat was bottom painted and put into the water, I'd say it acted just like an insulator.  Doesn't mean the problem is fixed on the sailboat, it just got bandaided.  But at least now he knows it's not his boat or his lift or his electrical wiring. 

I took a walk around the marina on Saturday and I couldn't believe how many shorepower chords were actually dipped in the water.  I know that technically it shouldn't be a problem since those chords are heavily insulated just for that reason, but it was a bit worrisome since that's not really what you want to do with those chords.  If they accidently fall into the water, it's a failsafe to have that heavy insulation.  But it's not the way they should be run.

Maybe that's why after the last season, my anodes looked like this.  They'll probably be the same this year when I get to them in about a week.

 

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I re-read his post and maybe you should too. See below and he is saying that the boat was removed and sold but not put back. We all make mistakes....  But also remember what most bottom paint is made up of.

 

 

  • Update to all who offered information and help.

 

Recently, my neighbor took his sailboat to the yard for a bottom job. Guess what, no more current on my prop!

His boat was the source, not mine. Fortunately, he has now sold his boat and it will be removed next week. Meanwhile, my boat is high and dry. 

 

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9 minutes ago, Iggy said:

I re-read his post and maybe you should too. See below and he is saying that the boat was removed and sold but not put back. We all make mistakes....  

Recently, my neighbor took his sailboat to the yard for a bottom job. Guess what, no more current on my prop!

His boat was the source, not mine. Fortunately, he has now sold his boat and it will be removed next week. Meanwhile, my boat is high and dry. 

 

Actually the blow boat was returned to the slip but his boat is out of the water. I would have been curious to see if the new paint would have made a difference. 

 

Stray currents is one reason I never swim in the marina. 

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49 minutes ago, Hatem said:

Let's reread it again, then.

That doesn't sound like the boat has been staying at the yard since it got bottom painted.  It sounds like it was brought back and the stray current solved by the bottom paint and whomever bought is it removing it next week.

At any rate, the OP doesn't really need to be too concerned with his anodes even.  I bet they're perfectly fine unless he leaves his boat in the water at his dock but that doesn't sound like it's the case.  He has it on the lift all the time so there isn't any current going through the props and the only time that happens is if he or his friend touches them, which is once or twice?  His boat is fine.

Question is, if indeed the bottom paint insulated the stray current (which it sounds much like that's the case), it must've covered a certain metallic part on the sailboat that was conducting the current and not just the fiberglass hull.  Perhaps the prop shaft and prop or the rudder(s) was covered in the paint.  Or there's a thru-hull or two that were leaking AC or even DC current and they were painted over.

 

Well it is not very clear if the boat is in the water or not. At lest to me...

I will put my neck out to say that 80 to 90% of bottom paint is copper. If the bottom is done right, it will not insulate any current. If done wrong, it will conduct if the current is there.

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Neighbor's sailboat was out of nearby slip for couple of weeks. During that time there was no current at my prop when I lowered boat into water. When he brought his boat home from the yard, there was no more current at my boat. He did have boat bottom painted and some 'other work.' regardless, the source was. his boat. Hopefully, the new owner will be removing this sailboat this week. Meanwhile, my boat is high and dry on it's covered lift. Sorry for any confusion.

Joe

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3 hours ago, docdixon said:

Neighbor's sailboat was out of nearby slip for couple of weeks. During that time there was no current at my prop when I lowered boat into water. When he brought his boat home from the yard, there was no more current at my boat. He did have boat bottom painted and some 'other work.' regardless, the source was. his boat. Hopefully, the new owner will be removing this sailboat this week. Meanwhile, my boat is high and dry on it's covered lift. Sorry for any confusion.

Joe

Don't be. Bottom paint or not, that boat has a A.C. problem. Your drive was the shortest path to ground and you felt it. Good luck!! 

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6 hours ago, Iggy said:

Well it is not very clear if the boat is in the water or not. At lest to me...

I will put my neck out to say that 80 to 90% of bottom paint is copper. If the bottom is done right, it will not insulate any current. If done wrong, it will conduct if the current is there.

Exactly. Copper Oxide is very conductive and that's why it is imperative to have a small parting line around the transom housing so the copper never touches the aluminum. The Tri-Lux out drive paints are TBD tin based as that is a lessor metal.  W

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Reading back in this thread you’ll discover that this neighbor is the fellow who felt the tingle on my prop. Not me. There is no tingle now when my prop in in the water. He did have some  electrical work done but not sure what. He is selling this boat soon.  Hopefully his next sailboat won’t cause a tingle. :-) if so the problem is likely in his dock wiring and lift. 

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18 hours ago, Hatem said:

Well it's clear now, yes?  So obviously the fix was either related to the bottom paint or some of the "other work" that Joe eluded to that the guy had done on the sailboat at the same time, which we don't know, but he should really find out for his own sake and future safety purposes.

HOLD YOUR HORSES, and your neck!  You're automatically assuming that the bottom paint that was used is the copper oxide antifouling paint that we all put on our boats, but you know that most sailboats have vivid-colored bottom paints which is different than the black, anti-fouling paint that we have.  Look around our area and in your marina at all the sailboats with blue, red, green bottom paint.  Those are different and contain white copper (cuprous thiocyanate), zinc or ECONEA as the biocide that fights marine growth instead of "cuprous oxide" and that is not the same stuff.  That's much closer to the same anti-fouling paints we do use on our aluminum outdrives that do not contain that conductive copper.  That might very well be the case here because what else can explain this phenomenon other than that? 

Not to beat a dead horse, but is the original owner of the sailboat in question still around?  If so, it might be beneficial to you to not only tell him that his boat was causing a stray current that was affecting your boat (and actually gave you a good zap), but to find out exactly what was the other work that was done to the boat.  Knowing that information will only help you in the future just incase there's a similar issue with the new neighbor.  Just a suggestion. 

How in the world can you assume that most sail boaters use a vivid paint from Pettit. Did you take a poll? With all the brands and types out there. Really?  Now I did my homework, as Wingnut stated "TBD tin based as that is a lessor metal." So that got me thinking......... I call Pittit, and Vivid paint does have copper in it. But they said "the copper is formulated differently" and "is conductive". 

ALSO, if you read my post I said "I will put my neck out to say that 80 to 90% of bottom paint is copper. "Meaning on the basis that you said "Question is, if indeed the bottom paint insulated the stray current (which it sounds much like that's the case)" I never said that he had copper based paint. My point was, that bottom paint will not act as a insulator. If anything, it will act as a conductor which Wingnut agreed and again Petiit conformed that Vivid will too. 

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