Battery wiring

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hooked
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Battery wiring

Post by hooked » Thu Nov 09, 2017 10:46 am

Can someone help me I have a 1989 F32 with twin gas engines and a genset my battery wiring is a mess. I want to re-wire it but I want to make sure it is all hooked up right to begin with. I am not sure where I might find a diagram. Thanks

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WayWeGo
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Re: Battery wiring

Post by WayWeGo » Thu Nov 09, 2017 5:54 pm

The best place to start is with a wiring diagram for your boat. You can get one as part of the full documentation package available from Beacon: http://www.trojanboats.net/wforum/viewt ... f=1&t=2695
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comodave
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Re: Battery wiring

Post by comodave » Fri Nov 10, 2017 5:26 pm

I agree that you should start with Beacon Marine and a witing diagram, however you may not want to rewire your boat as it was originally wired. Things have changed with the new (2011) NEC. Docks are going to have GFIs on them and Trojan did not wire these boats to work with GFIs if you have 2 shore power inlets. Trojan comingled the neutrals on the 2 shore powers. That will cause a GFI to trip. I just finished rewiring a friends 10.8 meter Trojan today. It has a Square D residential power panel with all the neutrals on one bar. Also had both the voltmeters neutrals daisy chained together. It would trip a GFI just by plugging it in. Now it does not trip with the loads on it. He also had one outlet that someone had switched the neutral and ground. He said "it always worked". Yes it did work but all the current returned via the safety ground rather than the neutral. His water heater also had a short between neutral and ground. Either one could have caused ESD. He did say that when he was in the water by the dock last spring that his muscles locked up but he thought it was due to the cool water...

It is a real problem with our older boats in light of the new electrical code with GFIs. Everyone does need to test their boats if you want to be able to hook up to shore power in a newly renovated dock. The problem of ESD is real especially in freshwater.
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prowlersfish
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Re: Battery wiring

Post by prowlersfish » Fri Nov 10, 2017 7:31 pm

I don't see combining the neutrals on the 2 shore powers causing a ground fault issue , Its really no different then a single 50 amp 220/240 cord wiring . I have had no issue with ground faults at all including some new docks/marinas with ground fault breaker . I have seen some issues with tying the neutral and ground together ( a real marine no no ) . With that said in many cases I am plugging in a single 50 amp with a splitter .
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comodave
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Re: Battery wiring

Post by comodave » Fri Nov 10, 2017 9:29 pm

When the neutrals are combined in the boat with 2 shore power cords, the return current does not necessarily return on the cord that it was supplied on. The dock GFIs are set to 30ma. Say you are consuming 5 amps on each cord, if more than 5.03 amps returns on one cord, the GFI will trip. If, on the other hand, you use a splitter or Y to combine your 2 inputs on the boat to one shore side plug, it will probably work because the neutrals are combined inside the Y so having them combined in the boat usually does not matter.
Trojan has been sold
1987 President 41 DC 225 Lehmans
Au Gres, Michigan

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prowlersfish
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Re: Battery wiring

Post by prowlersfish » Sat Nov 11, 2017 9:22 am

comodave wrote:When the neutrals are combined in the boat with 2 shore power cords, the return current does not necessarily return on the cord that it was supplied on. The dock GFIs are set to 30ma. Say you are consuming 5 amps on each cord, if more than 5.03 amps returns on one cord, the GFI will trip. If, on the other hand, you use a splitter or Y to combine your 2 inputs on the boat to one shore side plug, it will probably work because the neutrals are combined inside the Y so having them combined in the boat usually does not matter.


That makes a lot sense , honestly I am good with both AC and DC electrical but did not have a good enough understanding of GFI . But I did some studying . I was thinking as the neutral are tied together on the boat and on the dock (in most cases I seen) it would not be a issue . Of course I was wrong . Thank you .

It would not be hard to separate the neutrals . Of course you would need to change the cross over switch too . As most I believe are single pole .
TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat :D
2009 TROJAN RENDEZVOUS
Port Kinsale 2010 & 2011. Solomons get together 2011.

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Re: Battery wiring

Post by comodave » Sat Nov 11, 2017 4:55 pm

Yes, Trojan used a regular house Square D panel in my friends 1989 10.8 Meter. In a home all the neutrals go together as well as the safety ground. The problem is that a house does not have 2 service entrances, usually, but lots of boats do have 2 inlets. So you need 2 neutral bus bars that are seperated from each other if the dock has GFIs unless you use a Y to bring the 2 inlets together. We had to add a neutral bus bar in the 10.8 Meter since it only had one. If the dock does not have GFIs having the neutrals all on one bus bar will work. Safety is another matter... GFIs are constantly looking for the exact amount of current that is going out on the hot wire to be returning on the neutral wire. If it get a difference of 30 mille amps in the case of the dock GFIs the GFI will trip. It is going to be an ongoing problem for lots of older boats as more and more docks upgrade to GFIs. Some docks are installing one GFI per slip, some are installing one GFI per dock. It is cheaper to do one per dock than one per slip. The problem is that you are still limited to the 30 mA per GFI. So you have a dock with one GFI and 10 slips the 30mA is split between the 10 boats. If there are 9 boats already docked and each is leaking 3 mA and you pull in and leak 4 mA, the breaker will trip even though you are way below the 30 mA limit. You will be the bad guy and they will ask you to leave or not use power...
Trojan has been sold
1987 President 41 DC 225 Lehmans
Au Gres, Michigan

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