Okay- I finally had a chance to catch up on where this discussion has gone-uhhhhh, not sure I am any closer to solving my design. I already have my AC, House DC, and Electric Motor DC isolated. I just don't have any of them grounded. I have the AC hooked up, but the former green (ground) has no place to go as it was taken away when I pulled the old hunk of junk A4 (that shouldn't offend anyone on this forum). The house DC is wired back to the negative terminal through a bus bar that I installed in the engine compartment, but has no metal tie to anything that leads outside the boat. Let me clarify, I screwed the busbar down in to the engine mount which is composed of wood and fiberglass. The electric motor is just a closed loop as well with negative just returning back to the battery and no other connections or ground. So, that is the configuration. What can I do to improve it? I am operating in fresh water. The boat is stored at the local yacht club which I am pretty sure had a good running and grounded electrical system. I have a zinc anode on the shaft that is likely original with the boat that does not show any significant signs of pitting or wear. Dogs, people, and other boats are frequently around the boat in and out of the water and so far no problems. Other considerations are when we cruise, the marina and other conditions may change. I do have a generator that I will take with and potentially (no pun intended) use to either charge the bank or use to run the electric motor in case of the batteries being drained. Thanks for all that have contributed to this as I feel this is of big importance to current designs and any future builds or conversions.
Brian
--- In electricboats@yahoogroups.com, rob linda <rob_linda_2000@...> wrote:
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> I believe, that the reason of zinc becoming sacrificial if connected to the battery negative, because the lead of the battery plates is "nobler" (-0.13 Volt), than zinc (-0.76 Volt) causing electrolysis on a 24/7 base.Note, that a main negative switch is not much help if living or staying on the boat, since this switch will be "ON" , reason, I have independent switches for negative starter and windlass leads.I haven't mentioned yet the increased change on stray currents with battery negative grounded and anybody, who has seen the damage of electrolysis, specially by strays, will become careful to prevent this.
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> --- On Thu, 3/3/11, Tom <boat_works@...> wrote:
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> From: Tom <boat_works@...>
> Subject: Re: [Electric Boats] Rewiring DC electric system and Grounding
> To: electricboats@yahoogroups.com
> Date: Thursday, March 3, 2011, 1:58 AM
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> I worked on a newish French boat that had a battery switch on both negative and positive leads. Maybe that's why they did it.
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> At anchor I take the chain off the gypsy and ride to a nylon snubber. The chain goes around the samsom post just in case.
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> That doesn't take care of your engine ground issue, though. I suppose you could use a flexible synthetic coupling at the shaft.
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> -Tom
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> rob linda <rob_linda_2000@> wrote:
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> > Tom,My remark about "regulations" or "recommendations" was in response to Mike's and Eric's response.The reason of my original post was the "wisdom" or its opposite of connecting battery negative to ground since it eats zinc's and galvanizing of anchor chain.On most boats, NOT connecting battery to ground, can only be achieved if negative leads to starter motor (engine ground) and windlass can be switched off, which is often not the case on newly manufactured boats.Again, this is not an issue for electric propulsion, but also electric boats have windlasses.
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> > --- On Wed, 3/2/11, Tom <boat_works@> wrote:
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> > From: Tom <boat_works@>
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> > Subject: Re: [Electric Boats] Rewiring DC electric system and Grounding
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> > To: electricboats@yahoogroups.com
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> > Date: Wednesday, March 2, 2011, 10:23 PM
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> > The "propulsion electrical system isolation" is a reference to TE-30, which relates to electric propulsion in boats, not ICEs. It isn't difficult to isolate propulsion electrics from house dc systems.
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> > E-11 doesn't recommend isolating the battery negative from ground.
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> > "E-11.5.4.7.4 If the negative side of the DC system is to be connected to ground..."
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> > Also, be aware the ABYC Standards are recommendations, not regulations. There is nothing in the Code of Federal Regulations regarding grounding on recreational boats, as far as I have seen.
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> > --- In electricboats@yahoogroups.com, rob linda <rob_linda_2000@> wrote:
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> > > Mike, Eric,Thanks for responding.I agree with :"The boat's propulsion electrical system (e.g. batteries, generators, inverters) should remain isolated from the boat's grounding systemon-current-carrying conductive parts of the propulsion system (e.g. motor case) should be tied into the boat's grounding system per ABYC E-11 AC & DC Electrical Systems on Boats"However, if the negative lead for the starter motor is connected without a negative switch, as in many boats,o r the housing of the windlass is grounded, again without extra negative switch, there is a continuous connection between battery negative and ground, so isolation becomes  an illusion.Also during operation of ICE engine or windlass, isolation of battery negative from ground becomes impossible on many (most?) boats, simply because of the way starter and windlass motors are constructed.I am aware, that most motors used for electric propulsion have negative terminals isolated from
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> > > housing , so no problem there, to keep negative and ground separated.Chain, zincs etc are expensive, that's why I brought this up and sometimes "regulations" become illusions, if the construction of starter and windlass motors on small boats is not taken into account.
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> > > RobS/V Linda
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> > >  http://www.evalbum.com/preview.php?vid=3475 http://issuu.com/caribbean-compass/docs/compass_online_november10/27
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> > > --- On Wed, 3/2/11, Eric <ewdysar@> wrote:
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> > > From: Eric <ewdysar@>
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> > > Subject: Re: [Electric Boats] Rewiring DC electric system and Grounding
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> > > To: electricboats@yahoogroups.com
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> > > Date: Wednesday, March 2, 2011, 6:26 PM
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> > > I don't think that this forum of electric boat enthusiasts is the right group to determine the "correct" methodology for specific techinical questions like you have posed.
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> > > But there are a number of resources that can provide answers, like the ABYC and experts like Nigel Calder in his "Boatowner's Mechanical and Electrical Manual".
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> > > The ABYC seems to be the only group that has published definitive answers about grounding electric propulsion systems. Their standards state ". NThe boat's propulsion electrical system (e.g. batteries, generators, inverters) should remain isolated from the boat's grounding systemon-current-carrying conductive parts of the propulsion system (e.g. motor case) should be tied into the boat's grounding system per ABYC E-11 AC & DC Electrical Systems on Boats". This is from the "grounding" section of ABYC TE-30 Electric Propulsion Systems.
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> > > So the current carrying parts of electric drive systems should be isolated from the boat's regular (12V) grounding system and the 12V house system should be grounded just like any other boat. I also would assume that any AC system onboard an electric boat should be installed according to the standards defined for any other boat too.
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> > > Therefore, like Mike stated before, the propulsion system, the 12V house system and the AC system should be treated as 3 independant systems and the common boat standards for dealing with AC and 12V should be followed. This would include any "conductive path between battery negative and the ocean".
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> > > I hope that this answers your question.
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> > > Fair winds,
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> > > Marina del Rey, CA
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> > > --- In electricboats@yahoogroups.com, rob linda <rob_linda_2000@> wrote:
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> > > > Living on an anchored boat, I would like feedback on the following:Most anchor windlasses use a series (starter) motor with negative ground.The motor housing connects to the windlass, the gypsy, the chain and seawater, creating a conductive path between battery negative and the sea.It is widely believed, that this causes theÃÆ'‚ galvanizingÃÆ'‚ (zinc) of the chain to disappear rapidly.Reason I and many others have an extra switch in the negative windlass lead, which lives in the 'OFF' position, except when the windlass is used.On aÃÆ'‚ similarÃÆ'‚ note, some have an extra negative switch for theÃÆ'‚ starter motorÃÆ'‚ of the main engine, keeping negative and ground separated, to prevent the fast eating away of sacrificial zinc anodes etc.Both windlass motor and starter motor are typically automotive of the shelve.I have understood, that professional marine
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> > > > ELECTRIC boat forum should have a clear consensus on a simple question as :"Should there be a conductive path between battery negative and the ocean?"
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> > > > RobS/V Linda
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> > > > http://www.evalbum.com/preview.php?vid=3475http://issuu.com/caribbean-compass/docs/compass_online_november10/27
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