Shore Power and 110v Wiring

[TheScarab]

OK.

Trying to figure out what's going on with the wiring on the boat I just bought...

I'm a total non-technical newbie to electrical issues and wiring so please be patient with me. I'll be as descriptive as I can be and hope someone can walk me through rewiring this mess.

i have an electrical control panel that is dedicated to 110v wiring. along side it (on the back is another, separate panel).

The top switch is labeled 'Main' and has the black wire from the shore power wired to it. Across from this, the white wire is connected to the secondary panel. The green wire is hanging loose. This concerns me.

The other wiring appears to be ok until we get to the 'Inverter' switch. This appears to be the main switch for 110v coming FROM the inverter. This has a wire with a 3 prong plug on the end that is cut to length for fitting into the plug on the side of the inverter. One wire to the switch panel, two other wires to the secondary panel. However, the wire to the switch panel is white - but I suspect there are two whites and one green on this wire.

Below that is another switch labeled 10A Port. This appears to be the 110v wiring for the port side of the boat. This wire has the green and white connected to the secondary panel, but the black wire is not connected to the main switch panel.

Along one side of the switch panel is single (black) wires coming in. Along the other side is a series of short black wires connected to other switches on the same panel - like jumpers.

SO.........

I have a lot of questions and don't even know where to start.

First, is there any reason to have the disconnected wires.

What is the function of the smaller secondary panel with white and green wires? Is it just a ground?

What is the purpose of the black 'jumper' wires on the other side of the panel?

What 'typically' are the functions of white/green/black wires? ie: which is hot, ground etc.

Sorry for all the questions and absolute 'newbie' descriptions but I need to learn what this stuff does and how it works so that I can fix it now and in the future (if necessary).

Thanks in advance to anyone who dares to help

[sdowney717]

post a lot of pictures as a guide to see what you got there.

green grounds should not be dangling, perhaps they disconnected it to prevent galvanic corrosion.

[TheScarab]

Originally Posted by sdowney717

post a lot of pictures as a guide to see what you got there.

green grounds should not be dangling, perhaps they disconnected it to prevent galvanic corrosion.

i wish i could but i don't have a camera.

green is ground then. that's actually a help - thanks.

[sdowney717]

Originally Posted by TheScarab

i wish i could but i don't have a camera.

green is ground then. that's actually a help - thanks.

usually it is, unless someone botchinated everything.

for AC 120 volt
white is neutral
black hot
green ground

Should have a galvanic isolator to prevent corrosion. Current can run thru the ground wire such as a ground fault or some other boat leaking current in the water.

Another good idea is GFCI outlets and ELCI breakers, which when they detect faults trip the power.

[TheScarab]

ok stupid question....

what's the purpose of a neutral wire?

will check into a galvanic isolator because there is some corrosion throughout the wiring (on the ends).

[bobofthenorth]

Originally Posted by TheScarab

ok stupid question....

what's the purpose of a neutral wire?

will check into a galvanic isolator because there is some corrosion throughout the wiring (on the ends).

Oh dear. You really need to find a book or books and do some reading before you get yourself into real trouble. I'm a big fan of DIY but you need to take some personal responsibility for your own education.

Wiring in general is not something to take lightly and wiring on your boat can cause you real trouble - it can (literally) sink you or light you on fire. Not meaning to scare you - just trying to motivate you to do some reading. Then come back and ask the questions.

I haven't read him but Nigel Calder is supposed to be a good boat electrical authority. I suspect you may need to start with some more basic information though.

[TheScarab]

Originally Posted by bobofthenorth

Oh dear. You really need to find a book or books and do some reading before you get yourself into real trouble. I'm a big fan of DIY but you need to take some personal responsibility for your own education.

Wiring in general is not something to take lightly and wiring on your boat can cause you real trouble - it can (literally) sink you or light you on fire. Not meaning to scare you - just trying to motivate you to do some reading. Then come back and ask the questions.

I haven't read him but Nigel Calder is supposed to be a good boat electrical authority. I suspect you may need to start with some more basic information though.

yes, i understand.

i'm reading as much as i can. i've taken the time to determine where the wires are coming from and going to.

and yeah, i'm here on a boating forum asking for input specific to my system.

not sure what more i can do besides finding a local electrician, hiring on as an apprentice, getting my sub-contractors license and re-attacking the problem in a few years.

so thanks for stopping by my thread which began 'I'm a total non-technical newbie to electrical issues and wiring so please be patient with me.' and telling me that i need to learn about this stuff.

[TheScarab]

@bobofthenorth

just curious...

do YOU know what the purpose of a neutral wire is in a 120v wiring system?

[Tellie]

I'm with bobofthenorth, you might be a bit in over your head here. I admire DIYers as well and no offense meant, but you're showing a real lack of knowledge of the basic understanding of electrical systems. Attempting to work on your boats panels, shore power, inverters, etc. is not a good idea at all. I'd suggest at the least you start with Calders book as well, it's a great start. Even better would be to find a good qualified marine electrician that would be willing to spend some time with you on your boat. Perhaps investing in that digital camera might be a good idea as well.

[TheScarab]

lol...

anyone else want to tell me to go learn about wiring before i start?

kind of thought i'd get some first hand info here, maybe LEARN a bit.

instead so far it's just folks telling me that i shouldn't do it because i don't know what i'm doing...

NO ****................

what good is a community forum for sharing info and ideas (LEARNING) when people's only input seems to be YOU NEED TO LEARN?

[sdowney717]

the white neutral wire carries the current back to the source from where it came.
the power comes in on the hot black wire.

At a 'service entrance' location, both the neutral green and white wires are joined together physically. And that is the only point where they do join. This keeps the green safety ground from carrying power EXCEPT in a short situation where hot wire might accidently touch a grounded appliance. Boats are like a big appliance plugged into a shore power connection.
In your house the green and bare copper ground and white wires are joined in the main service entrance breaker panel. On a boat that would be some main service breaker at the marina.

You need to study the basics of how wiring works to get a better understanding of what your dealing with. And dont work on live circuits.

[TheScarab]

Originally Posted by sdowney717

the white neutral wire carries the current back to the source from where it came.
the power comes in on the hot black wire.

At a 'service entrance' location, both the neutral green and white wires are joined together physically. And that is the only point where they do join. This keeps the green safety ground from carrying power EXCEPT in a short situation where hot wire might accidently touch a grounded appliance. Boats are like a big appliance plugged into a shore power connection.
In your house the green and bare copper ground and white wires are joined in the main service entrance breaker panel. On a boat that would be some main service breaker at the marina.

You need to study the basics of how wiring works to get a better understanding of what your dealing with. And dont work on live circuits.

THANK YOU. your post was actually helpful - and i appreciate it.

just find it amazing that i say 'i have a dangling ground' and the consistent advice is 'DON'T TOUCH IT BECAUSE YOU MIGHT BURN YOUR BOAT UP'....LOL

ok...so i lied a bit...i do know [a little].

[sdowney717]

the advantage of an ELCI breaker on your boat's main entrance power line, is this. If your boat has a wiring problem that might kill you, the ELCI will likely detect that and kill the power coming into your boat right at the shore power hookup.

An ELCI breaker trips at around 30 milliamps of current leakage, only 10 milliamps or a little less can kill, but at least an ELCI will not nuisance trip all the time.
A GFCI breaker trips at a 5 milliamp current leakage, which can save your life.
And really all your outlets on the boat should be GFCI protected except maybe for the fridge.

If your boat had GFCI on the shore line coming in, it would likely nuisance trip frequently, so the ELCI is a compromise for usability issues. ELCI is just a new boat requirement. Old boats dont have to be retrofitted.

[TheScarab]

thank you again...this is helping

[CarinaPDX]

I'm a big fan of DIY for cruising, but it looks like you are WAY over your head if you don't understand Line-Neutral-Ground differences, and know the color codes. This is not meant to offend you, but alert you that this is something that needs knowledgeable eyes. One could fill volumes about the grounding issues alone; the green wire may have been intentionally disconnected for good reason, but it also could be a safety hazard. As noted above, a galvanic isolator is now considered minimum equipment by the ABYC folks, and there is a very good chance you don't have one if the boat is old. Personally I prefer using an isolation transformer that can also be used to step down 220v (or step up 110v if the boat uses 220v). This is probably meaningless to you, so just trust that someone needs to put together a circuit diagram of your AC power system, and recommend changes/upgrades. If you don't have someone in the marina who is knowledgeable and willing, then hire a professional marine electrician - it will be worth every penny. This is simply not an area that can tolerate errors - it is critical to the safety of those aboard, and to the boat itself. Of course people here will try to help, but nothing can replace those knowing eyes seeing first hand the situation. Good luck...