New Electrical!!

[CuttingEdgeNY]

I'm new to the marine industry and I have been taking my time rebuilding a boat that was given to me. It's a 28' Flybridge with a single chyrsler 360 5.9L inboard. I got done all of the structural and now am at the stage for installing the electrical end of it. I'm very familiar to home ac wiring, and also dc wiring, so the dc wiring isn't my concern, just the ac. I have searched on google for hours, read through many forums, and even read through ABYC standards. I don't know where to find information of complete ac systems information and installation. For example;
-Neutral-white connects to ground-bare, but where, some say at ground bus bar, others say immediately at initial connection?
-Breakers only have two posts on back to connect(which I believe is just load and line for "in and out" of switch. Where does neutral go?
-Safe way of wiring shore power in
-Inverter wiring for when off shore
-Does DC and AC grounds connect at the same spot?
-etc..
All this stuff I have been trying to find and nobody seems to have it written down somewhere. I haven even looked through books, which don't have all this info. Thanks for reading through this long of a post, but any info regarding this matter would be greatly appreciated!
Thanks, Ken

 

[Bob_VT]

Re: New Electrical!!

Welcome to iboats.

I will move this to electrical ....... I have no idea

 

[Silvertip]

Re: New Electrical!!

Powering a boat that has AC and DC power starts at the dockside shore power receptacle. A cable connects between the dockside outlet and a power inlet connector on the boat. From that shore power inlet, AC power is fed to an entrance panel not much different than the one you find in a house. Power is then distributed to the various branch circuits with appropriate GFI protection. However, since a boat also has many DC circuits, the power system often includes a power conversion system that converts 117 VAC to 12 VDC for charging the starting and house battery banks and to provide power to those DC systems while at the dock. The system may also include an inverter that converts 12 VDC battery power to 117 VAC while not connected to shore power. Obviously that system cannot tolerate high current loads for extended periods of time unless the boat also includes a generator. If a generator is included then a transfer switch (manual or automatic) is required. What you need to research is "marine shore power systems". There are many and there are many adaptations so do your research carefully and by all means figure out your needs before you begin the project. Sizing the system for the anticipated DC and AC loads is critical especially if you plan to add airconditioning, electric heat, television, high power sound systems and any other high current draw items.

 

[RickJ6956]

Re: New Electrical!!

-Neutral-white connects to ground-bare, but where, some say at ground bus bar, others say immediately at initial connection?

AC Neutral and AC ground are never connected together on the boat. Also, the AC ground on a boat is not a bare wire. It is a wire with green insulation.

-Breakers only have two posts on back to connect(which I believe is just load and line for "in and out" of switch. Where does neutral go?

Except for the Mains on some boats, circuit breakers switch only the hot (black) wires. Neutrals (white) are tied together.

-Does DC and AC grounds connect at the same spot?

Yes, usually at the engine block.

All this stuff I have been trying to find and nobody seems to have it written down somewhere. I haven even looked through books, which don't have all this info. Thanks for reading through this long of a post, but any info regarding this matter would be greatly appreciated!

Here's a good starting point.
iBoats also has an electrical how-to section but it's focused more on DC wiring.

I would advise getting a professional involved, both at the design stage and to periodically inspect your work.

 

[CuttingEdgeNY]

Re: New Electrical!!

Thanks for the replies guys, I really do appreciate it. But where I am confused is after reading the ABYC codes, and then reading other posts, even the replies to my thread, is that the codes say neutral is supposed to be a grounded conductor, as well as the ground. Now, when you say, neutral isn't supposed to be grounded on the boat, does that mean that the dock shore power is neutral grounded and when I run the neutrals in the boat, that they all get connected to a common bus bar(not connected to ground)? The reason why this seems a bit confusing is that, in home wiring the breaker contains the hot and neutral, and ground goes to a common bus bar, but marine breakers only contain posts for hot, so hot goes to breakers, ground goes to common bus bar, attatched to engine block, and neutral goes where?
Does anybody have a good book or reference manual that you know of that would contain these kind of answers. I have really looked long hours for this information, and I'm so surprised that nobody has a common wiring diagram on what wires go where,(mostly into and out of a breaker panel). Thanks again.

 

[Bondo]

Re: New Electrical!!

The reason why this seems a bit confusing is that, in home wiring the breaker contains the hot and neutral,

Ayuh,... I've Never seen that,... Ever...
Hot is fed through the main to the breaker,+ only the Hot comes off the breaker, to the appliance, with the neutral going to it's bus-bar,+ the ground going to it's bus-bar...

I think part of your problem is you're confusing Ground, Neutral,+ Bonding....
While all are similar, they're also quite Different...

 

[Don S]

Re: New Electrical!!

Lots of good information here. http://bluesea.com/resources/2

 

[CuttingEdgeNY]

Re: New Electrical!!

Would you guys say this is correct? This diagram answers alot of my questions. The only question I have left is, the two bus bars the neutral and ground connect to, are not connected and just next to each other, or are they all connected? I also don't know what the three circles represent. I think leds but looking at their wiring it doesn't seem to clear on their purpose, especially the middle one, the bottom wire looks like it goes on the breaker or something? Thanks

 

[RickJ6956]

Re: New Electrical!!

It looks correct. The top indicator tells you there's power and the bottom indicator lets you know if hot & neutral are reversed. Notice the buss bars at the bottom -- neutral is not bonded to ground.

Again, neutral should be bonded to ground only at the service entrance panel. This means the marina's service entrance panel. The dock connection and the connection on the boat are not bonded.

Major confusion among DIYers exists because of the "legal" names of the neutral and ground: Grounded conductor (neutral) and grounding conductor (ground).

Neutral carries current. Its purpose is to provide a return path for the current that's drawn on the hot(s).

Ground does not carry current unless something goes wrong. Its purpose is to stand-by with its path of least resistance to take potentially deadly faults to ground.

Electricity wants to take the path of least resistance to ground. If the grounding conductor was not there (or if it was not properly connected), that path could be through a human touching both the metal case of a fridge and a water faucet.

 

[imraan47]

Re: New Electrical!!

This might help you with your inverter..

Video by west marine.
http://www.westmarine.com/webapp/wc...isor/10001/-1/10001/selecting-an-inverter.htm