battery charger wiring

According to my diving service (whom I am not convinced is truthful) I am going through one shaft zinc a month. They never leave the remnants behind so I can't verify and I refuse to hop in the nasty water of Marina Del Rey. BUT, I would not be surprised if I had stray current so I'm inspecting the wiring and installing a galvanic isolator. I noticed that the Newmar battery charger is wired a little funny. The black wire is going to the neutral bus and the white wire is going to the switch (and the green is going to the ground bus with all the other green wires). The battery charger seems to work fine and the batteries seem fine as well.

Can the charger still work right if it was wired incorrectly?

My reverse polarity light has probably burned out long before I took over the boat a few months ago so I'm not sure if that would go on. But my galvanic isolator with monitor can do that chore. The only reason I leave the boat plugged in is to charge the batteries after a day of sailing and using the fridge - plus I want to run the dehumidifier. Would it be better to plug an extension cord into the shore power to run the dehumidifier instead of plugging in?

Inspect your zinc's yourself.

Dan, I recently read somewhere (possibly this List?) that a great way to inspect such things as your zinc without getting one drop of water on yourself is to make a cool inspection tube from 2" to 3" PVC or ABS pipe three or four feet long with a piece of clear Plexiglass in the end. Then you simply stick the pipe in the water in the direction of the zinc and see for yourself. I'm out to the local plastics shop this afternoon to make one where I'll ask them for the best combination of pipe materials that go with the best kind of plastics and plan to have one made by sundown. Want to borrow it? Call me on my cell at 310.804.9198. Glyn Judson, E31 hull #55, Marina del Rey, CA

Dan

I use S and K dive service and yes I have the same problem.

My zincs were going at the rate of every other month and I know they were telling me the truth.

I plan to install an isolator.

I agree the wiring in a little funky if you're used to land wiring.

My solution for the short term is I don't plug into shore power at all, unless I'm at the boat or a few days before a Catalina trip

John

Sacrificial Zinc needed?

Given I'm new to this, I don't really know much (at all) about zinc anodes.

Would one be needed on my E27 that has no shore power inlet?
I only have two group 27 batteries in series.

Thanks
mn

marcusn said:

Would one be needed on my E27 that has no shore power inlet?
I only have two group 27 batteries in series.

Click to expand...

Almost certainly, yes; even if it is just on an outboard.

If you want to understand the principles involved, I would recommend getting hold of a book like one of these:

http://www.amazon.com/Sailboat-Elec...4051153?ie=UTF8&s=books&qid=1193598349&sr=8-5

http://www.amazon.com/Boatowners-Me...4051153?ie=UTF8&s=books&qid=1193598418&sr=1-1

The Nigel Calder book is expensive, but explains all the reasoning behind how you build a complex boat electrical system over the course of several long, detailed chapters. Don Casey is much simpler, and cheaper, but would tell you all you really need to know.

A brief description: do you remember when you were ten years old at school putting copper and zinc electrodes in salt water and creating electrical current? When you put a boat in the water, and immerse dissimilar metals such as a propeller shaft strut and a propeller, you create the same situation. Do you remember how, after you pulled out the copper and zinc after a while, the zinc had been eaten away? That will happen to one of your underwater metals, unless you have a 'sacrificial zinc' to get eaten away instead.

The process is slow, unless you are permanently plugged in to shore power, in a marina with lots of other boats leaking electrical charge, in which case the situation can cause damage quite quickly.

But if you have a propeller in the water, you need a zinc.

Gareth
Freyja E35 #241 1972

One of the first things you need to do is to buy a 'reverse polarity' indicator....any Radio Shack or hardware store. Plug it into a convenient AC outlet and see if you have a problem.
Never connect either the white (neutral) or ESPECIALLY the black (hot) wire to your ground buss.
Howard Keiper
Sea Quest
Berkeley

Turn Off Your Shore Power !

My routine is to Charge the Batteries when onboard for the weekends.
The Batteries hold a good 12.7V Charge during the week and I turn OFF
the Shore Power AT THE BREAKER when not on the boat.
The whole thing is to leave your Shore Power OFF when not needed.
This saves on ZINCS big time. The next is to ISOLATE the Shore Power
Ground from the House System.....very controversial per ABYC....
good way to cut down on your Galvanic Corrosion.
Test the available Current in the water to your boat to see possible problems.
This is a HUGE subject for Cruisers, due to the Substandard Electrical Wiring
in remote locations.

Happy Zincs

gypsyrecs said:

My reverse polarity light has probably burned out long before I took over the boat a few months ago so I'm not sure if that would go on. But my galvanic isolator with monitor can do that chore. The only reason I leave the boat plugged in is to charge the batteries after a day of sailing and using the fridge - plus I want to run the dehumidifier. Would it be better to plug an extension cord into the shore power to run the dehumidifier instead of plugging in?

Click to expand...

Sorry, I meant to address this with my last reply, but got distracted. I had reverse polarity for over a year after buying my boat without realising it (I only found out when I tried to plug in an inspection lamp in the dark, managed to cram the wide prong into the narrow hole, and it lit up with the other prong just touching the stainless face plate). As Howard says, check for it first, you can also test for it with a multimeter. Sometimes the dock may have reverse polarity even if the boat is properly wired.

There was a lot of stray current at both the marinas I was at, so I avoided being connected as much as possible. A small solar cell is a great way to keep the batteries at full charge while you are gone. Do you need the fridge while you are not at the boat? During the humid season, it would be better to wire the dehumidifier directly to the dock bypassing the boat's electrical system.

Gareth
Freyja E35 #241 1972

I would second the recommendation for the Nigel Calder book. IIRC, there is a section on how to test your electrical system for problems like this. You may find that you have some basic electrical issue that the GI may mask at significant cost. Diagnose the issue first before spending your money. RT

I just reread Dan's post and agree with it except that turning off the AC at the dock breaker doesn't (or shouldn't) have anything to do with the ground. Maybe that's part of the problem. Anyway, he's right on as re the GA. They should be OEM'd on every boat.
Howard Keiper
Sea Quest
Berkeley

Reverse Polarity

I have seen a number of the 1970's Ericsons wired incorrectly from the factory. Most of them have had the neutral side breaker protected instead of a> The hot side, or b> better both the hot and neutral. Although 2 of them have been wired reverse polarity in the boat. (This however could have happened in the years between initial purchase, and when I surveyed them).

I recommend everyone check this out on their boats. And always install GFCI in the first plug on each leg of the 120. This is easy to do on the ericsons.

Guy

Thanks for the replies everyone. I would have responded sooner but got a cold right after my first post. Anyway, Glyn, I will definitely give you a buzz re the reverse periscope! And I would love to see your boat. I've never seen a 31 in person. And growing up in <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-comffice:smarttags" /><st1:State w:st="on"><st1lace w:st="on">Maine</st1lace></st1:State>, I have an affinity to the Friendship Sloop style of boat.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>
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I need to re-ask my question because I think it was assumed that I was being facetious but in reality I honestly don't know the answer: If an AC electrical device was wired with the neutral to the switch and the hot to the neutral bus (and ground to ground bus) would the device operate normally? And is there anything wrong with that?<o></o>
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I can’t see if they just used the wrong color wire without taking the charger out and… well, without some surgery. And I have tried to research the answer but it is never talked about – not even in the Calder book. I’m starting to think it must be one of those basic questions everyone is just supposed to know…. If that is the case, please pardon my ignorance…<o></o>

If an AC electrical device was wired with the neutral to the switch and the hot to the neutral bus (and ground to ground bus) would the device operate normally?

Click to expand...

The question is dependent on whether the charger case is grounded to the boat's AC ground (normally through the green wire). If it is you are OK. If not, you may have a safety problem even though you already know the charger is charging properly. You don't want to zap yourself or other equipment.

Measure voltage between the case and the boat's AC ground. It should read zero, but with a digital meter the reading will jump around a lot if there is no ground. While jumping around it should stay within a few volts of zero to be safe.

If it doesn't exist, adding a ground wire is the safe approach.

It probably would appear to be working properly but what you have described is the classic 'reverse polarity' condition...and it can be dangerous, working or not.
Tha ABYC is emphatic about the case ground...you MUST, not just may want to, ground the case. Further, that ground must be the same gauge conductor as any of the output conductors.
Howard Keiper
Sea Quest
Berkeley

I should correct myself here. what the ABYC says is that metal cased units must have an AC grounding conductor attached from the case to the AC ground buss. (ABYC A-20.7.3).
There should also be a grounding conductor from the case to the DC ground buss (engine, or it's buss). It's the DC case ground that needs to be no less than one gauge lighter than the output conductor. (ABYC A-20.7.4.2).
Howard