Need Electrical help....getting a little shock!

[Ross]

To give you an idea of just how exciting 115 volts ac can be I will cite an experience from some years past. One of my customers asked me to check an outside outlet mounted on a stone masonry porch column. She said it "shot fire " when her kids used it to vacuum the car over the weekend. I removed the cover plate and the plastic parts of the outlet fell apart and the remaining parts struck an arc that burned for about 30 seconds without tripping the breaker. When it went out I killed that breaker and replaced the receptacle. The wires were not damaged only the contacts of the old receptacle were involved in the arc. I unscrewed the remaining bits and installed a new receptacle. Had that arc occured inside the house it would have resulted in a major fire.

Edit to correct spelling

 

[Mike B]

Brobins, just some more education for you in the event you weren't aware of it. AC is more dangerous not just because we're talking 110V vs 12V in a DC system, but because AC runs on the same 60 cycle frequency as do our hearts. Should you get shocked at just the right moment it can throw your heart into defrib and stop it dead. Just remember to always show it respect, do your best to never touch a wire unless you're 110% sure it's not live. Never put yourself in a postion where you'd touch a live wire while your other hand or torso is touching something conductive. This helps avoid any current running through your heart. Don't mean to be an alarmist but also don't want to see you get zapped. Good luck with the repairs and keep us posted.
Mike

 

[jackhartjr]

Also not trying be an alarmist...however...it appears you are not familiar with electricle work.
That said...PLEASE...STOP!
Find someone that does and pay them to make sure it is done right...you will learn a lot in the process.
I have a friend that lost most of his forearm because he didn't know...
Being a friend!
Jack

 

[luvitt]

btw, i figured it out. I was holding on to that pole again, reaching into a tight space, and I brushed my hand against some wiring for a dc light and got a tingle. The light is no longer used as the previous owner remodeled the nav station and it got covered. So, I knew i shouldnt get a dc shock, and I let go of the pole and (dont yell) touch the two wires together briefly, and they sparked. So I touched both of them again with my fingers, and no shock (not touching pole). Then i removed the AC ground from the engine that I had inadvertantly installed. Now, I touch the pole, and the dc wires and no tingle! I was getting tired of avoiding that pole.

 

[Ross]

You still need to KNOW how that boat is wired.

 

[sailingdog]

Yes, Ross is right. There are some obvious electrical issues on that boat, and you really need to know what the situation is. Adding just a ground wire shouldn't have caused that kind of serious problem, and the fact that it did means that you need to investigate further.

You still need to KNOW how that boat is wired.

 

[Stu Jackson]

You can lead a horse to water...

and perhaps he's learned, but I'm NOT too sure. I'm awaiting his wiring diagram.

Good luck, buddy, but if all ya got is "I removed the AC ground I INADVERTENTLY... then it's either a planning issue or an implmentation issue, or...both.

Good luck. I never say that when it comes to electrical systems, but in your case...

 

[dubh]

Stop!

btw, i figured it out. I was holding on to that pole again, reaching into a tight space, and I brushed my hand against some wiring for a dc light and got a tingle. The light is no longer used as the previous owner remodeled the nav station and it got covered. So, I knew i shouldnt get a dc shock, and I let go of the pole and (dont yell) touch the two wires together briefly, and they sparked. So I touched both of them again with my fingers, and no shock (not touching pole). Then i removed the AC ground from the engine that I had inadvertantly installed. Now, I touch the pole, and the dc wires and no tingle! I was getting tired of avoiding that pole.

Figured it out? FIGURED IT OUT??? "it got covered"??? What was buried? What's energized???
Please, you're not hearing what is being said. Unplug all land power cables to the boat. Turn your battery switches to off. Go find a qualified person to look at your system.
I had an '85 40'. redid some of the minor work myself, but had professionals install the AC for air conditioning and electronics. Expensive? Yes, but I'm still alive, and have traded up that boat. By the way, I have rewired power and LV systems, but try to know when to ask for help.

 

[Ross]

Re: Stop!

This is a good time to relate an incident I had years ago on a house with aluminum siding. I was installing a dryer vent through an outside wall. Standing on an aluminum ladder I reached in through the hole in the wall and got hold of the vent pipe with my bare arm inside the pipe. When that piece of pipe touched the aluminum siding I received the most severe electrical shock of my life. I went looking for the problem and finially found that someone had cut a very ragged hole in the aluminum porch ceiling soffit that was in contact with the wire for the porch light. EVERYTHING about the outside of that house was electrically hot even the propane tank and the copper lines into the house. The home owner told me the gas man complained of getting shocked when he would connect the hose from his truck. In dry weather it wasn't much of a problem and on a rainy day it wasn't because the man would be wearing boots but for a few days after it had rained it was dangerous to lean against the side of that house.

FIND and REPAIR that problem before it kills somebody.

 

[Scott T-Bird]

Since you are determined to be a DIY'er

Get a book to help yourself out with. I didn't buy Calder's (but I figure I should) but I did get Don Casey's Sailboat Electrics Simplified. Use this website for your book purchases.

I just reviewed the section on "The Green Wire Controversy". It seems that it isn't just that simple to say 'connect the green wire to the engine' or 'disconnect the green wire from the engine'. Casey makes the point that grounding the green wire from the buss bar to the engine block reduces the risk to swimmers if there is AC leakage into the DC system (which can happen with certain equipment). However, he makes the point that if the ground from the power source is faulty, then ground-fault current will flow to the water - just what you are trying to avoid. So it is very important (if you are going to connect AC ground to the engine block) to test the ground at the dock and verify that all your power connections are properly grounded. He also points out that protecting all AC circuits with GFCIs virtually eliminates the risk of ground-fault current flowing into the water through the engine connection.

When I purchased our boat, I noted that the green wire from the AC ground buss was connected to a negative post on one of my batteries. I suppose this is the same as grounding to the engine block since the negative posts are grounded that way. I never had any occasion to hook up to shore power so I never gave it any further thought for several years. Last spring though, when my marina installed my batteries and splashed the boat, they connected the green ground from the AC ground buss to a red post on the battery. They put me in a slip where I could plug into shore power so I decided to take advantage of it on a temporary basis. Before plugging in I checked out the wiring briefly and I was alarmed when I noted the ground tied into a positive post. I don't suppose it makes a difference since there is no other connection to complete a circuit, but I decided to remove the AC ground altogether from a connection to the engine block. I figured I would look into this a little further before deciding what to do about it.

I guess I'm still uncertain, but it makes no diffence this year - still no shore power for me.

 

[Ross]

Re: Since you are determined to be a DIY'er

The only place your DC circuits and your AC should meet is at your battery charger and your inverter.

 

[luvitt]

The only place your DC circuits and your AC should meet is at your battery charger and your inverter.

Exactly.... I made the mistake of adding an AC ground to the engine....I'm very familiar with DC, and made a mistake. I promise all of you, everything else is wired properly. I replaced my faulty extension cord with a proper 30 amp shore power cord, and it's all cool. I mean, its still just wire's to accessories right? beside the fact that it's 3 wires instead of 2, and it's AC instead of DC, its basically power in, power out (and the 3rd wire). Not only did i wire it exactly like the old wiring (except my own added engine ground), I did make a diagram. Just to clarilfy, I drew it out on paper (albeit by hand), I removed old wiring from accessories as I installed new wiring, I did it one wire at a time, matched my diagram, and tested individually. I did lots of net research as I did it, but I still screwed up with that AC engine ground. I understand better now. Im getting a survey soon, and I will triple check with the surveyor, but Im pretty darn sure it's right now. The AC being connected to the DC side through the ground was not a good idea.

I do have an excellent digital DC diagram I will post for your thoughts, after I find on one of my 6 scattered pc's once I find it. I will try to make an AC version for your comments soon. The AC wiring was original, and certainly could have used rewiring anyway ('86), so following it should have sufficed.

My mistake was that I mistook some wiring in the engine compartment. It was disassembled there, and wiring from the Heart inverter joined the AC system in the engine compartment, and I assumed it was connected there. I removed the destroyed inverter and traced the old wiring to its disconnected point, and assumed it's connection point was at the engine block along with the DC. Everything else was connected straight from breakers to accessory. and it matched what i planned on paper.

Im a little bit of a renegade hippy with short hair. maybe a redneck (not). I dont have the money to do a lot of things. I try to do it right, and it has taken me over a year so far, and maybe another 3-6 months if I make it pretty. Thats why I'm on this forum, to learn, and to figure out stuff. I can't always afford a book for everything. I cant afford a professional. Thats my life. if i want it, i gotta do it. I have a new young bride, and I make s#!t for a living. I can't take away from her, but I still want this. So please understand my unorthodox ways. Life wasnt supposed to be this way, but it is, and i still have a dream. No, i dont want to be electrocuted to death, but I do take risks like touching DC wires that were improperly grounded with AC. What else do I have to live for!

I wish you guys could see my boat. See what I started with, see what I have now. Completely by myself. 0% help, except what i got from this site. I thank you all. I moved the entire cabin (including sole) of this 40' boat, piece by piece, from a storage unit 6 hours away, in a Honda Fit (tiny hatchbatch), and installed it all, like a puzzle, with no directions. I learned a lot from this site. I have a YACHT! and it's beautiful! I know her inside and out. if I ever have a problem, I know how to fix it.

Live or die,

B

 

[luvitt]

Me.

 

[Scott T-Bird]

Ross, Casey does mention the charger and inverter

Other ways he mentions that there could be a leak from AC current into the DC system is crossed wires (I suppose abraded AC wires crossing abraded DC wires) which doesn't seem like it should be a common occurence. Also, dual voltage appliances ... I'm not familiar if there are refers, water heaters, air conditioning units, light fixtures or any electronic units that may have dual voltage connections. But that would also require a short in the offending appliance.

The dangers of connecting the ground to the engine is that it opens the door to galvanic corrosion or, even worse, stray current corrosion. Still Casey seems to recommend that the green wire connection be made with the caveats that:
1. Testing the ground at the dock is essential.
2. Disconnect the power at the dock when swimmers are in the water.
3. Disconnect the power at the dock when leaving the boat to isolate from galvanic or stray current corrosion and use a solar panel for charging when not at the boat.

To me, these seem like pretty inconvenient caveats (except the one about disconnecting shore power when swimmers are in the water). I doubt that I would ever go into the water purposely at just about any marina that I can think of except where we keep our boat because there is no shore power anywhere nearby! I often swim to and from the boat to avoid using the dinghy.

I don't have a charger or an inverter, and no dual voltage appliances. I can inspect my wiring to make sure there is no short between AC and DC wires. It seems that my best solution is to eliminate the green wire connection to the engine.

 

[Stu Jackson]

THIS is where the CHOICE really comes in for each of us

The dangers of connecting the ground to the engine is that it opens the door to galvanic corrosion or, even worse, stray current corrosion. Still Casey seems to recommend that the green wire connection be made with the caveats that:
1. Testing the ground at the dock is essential.
2. Disconnect the power at the dock when swimmers are in the water.
3. Disconnect the power at the dock when leaving the boat to isolate from galvanic or stray current corrosion and use a solar panel for charging when not at the boat.

To me, these seem like pretty inconvenient caveats...

Scott, you're right, and Calder also says pretty much the same thing.

The choice is that you never know where you're gonna plug in, since many folks do when they visit "strange" marinas (electrically speaking!)

Rarely do people check wiring at new or visited marinas, watch out for swimmers or #3 of your 1,2,3 suggestions when they're traveling. Rarely do they do that even at their own marinas, partially because not enough people know or learn enough about electricity - remember: it's that "it's too complicated for me" subject!

That why the CHOICE of combining the grounds or NOT is an important one, so YOU know how and WHY your boat is set up.

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B - Congratulations and thanks so much for explaining your background, abilities and workmanship to all of the rest of us. Many of us are in "the same boat" as you are, and understand the limitations imposed by reality and work hard to overcome them. I think we all feel better for you, we now finally understand the homework and research you've done, and your success at it with safety as your first and foremost goal. That's what's required to actually make things work so we can all have fun out there. Thanks for the input and the great topic.

 

[luvitt]

thanks for the encouragement. I did do some research in the books mentioned, didnt buy them but read them and took notes at the local barnes & nobles.

however, I realized the other day that I did not fix my problem. i plugged in a real shorepower cord also. The problem seemed to disappear, but oddly reappeared in a different place. now when i touch my helm, and railing at the same time I get a tingle! im not liking this.

I thought it was fixed. and I considered grounding to the engine and adding a galvonic isolator. this is wierd. it stopped shocking me in one place, and started shocking in a totally different place!

Now that I read the books, I think i will just start over and trace everything with the power off. its going to be much more difficult this time though, as the first rewire was done before i rebuilt the cabin. now i have everything in the way.

Good news though, I have a charter capt as my neighbor on the hard, and he is preparing to rewire his vessel. One of his good friends is a very renowned electrician and supposedly was involved in fixing the epirb system recently. I told my neighbor about my problem while I offered him a 16' treated 4x4 that I had no use for. He offered to have his friend inspect my wiring! he told me the guy likes scotch. 1 bottle comin up!

also, ive been working parttime at boatersworld and they have the Boatowners electrical & mechanical book on clearance. I think i will get it. it's a good reference and will come in handy.

im still not clear on the green grounding situation. The books 'recommend' to ground it to the engine or boat ground and warn of the electrolysis problem and say to fix it with a galvonic isolator or isolation transformer. the odd thing is, they dont tell you what to do with the green if you choose not to follow the 'recommendation'. I understand the ground & neutral are connected on the shore side. but if you dont ground to the engine, what do you do? just lead all green to the buss bar and forget about grounding the buss bar? the way im interpreting it is as such. green from the main goes to the buss and all accessory greens go to the buss. plug in the shorepower cord and green is connected to neutral at the dock and grounded on shore.

when i got the boat, there were all kinds of "boxes" & inverters, and electrical items that were corroded pretty bad. I guess the first thing i did was rip them out and throw them away. I bet one of them was a galvonic isolator, hence my ground to the engine. the greens led to the engine, but i missed a piece of equipment. as a matter of fact I see a green cable leading from under the aft berth (where the gizmos were) that ends in the engine compartment. I think i left it there for a reason, but since forgot.

btw, i rewired the DC too. completely. but im confident with that. I used all new Ancor cable of the proper gages and proper connections & lugs & heatshrink, etc. I totally rebuilt the distribution panel with all new breakers from ebay. Got a pretty good deal. I even bought all new led's from radio shack and wired them up too. I still need the meters, which could have helped by now.

Thanks guys,

I will let you know when it is properly and fully resolved.

 

[Stu Jackson]

Ya just gotta keep reading

U wrote: the odd thing is, they dont tell you what to do with the green if you choose not to follow the 'recommendation'. I understand the ground & neutral are connected on the shore side. but if you dont ground to the engine, what do you do? just lead all green to the buss bar and forget about grounding the buss bar? the way im interpreting it is as such. green from the main goes to the buss and all accessory greens go to the buss. plug in the shorepower cord and green is connected to neutral at the dock and grounded on shore.

C'mon, if you don't know, keep them disconnected. Don't interpret on your own, kieep reading and talk to your friend's friend. Trace it down and do it properly.

 

[Ron20324]

I'm miles away from my reference books, but someone must be looking at Calder? I would think you wouldn't ground the green shore lead to anything on the boat other than the appliances and/or outlets that use 110. Engine ground is not necessarily "earth" ground. To ground the green lead means any power inadvertantly applied to the shore cord green would be fed into the boat (AC polarity reversal light would come on?). Then every battery neg wire would probably have 110 on it. Same for the battery neg- it would always be fed to the dock power head. Not a good idea, I would say. Quick, someone call Calder.

 

[Bob Poff]

Good change of course

Well brobins, you've made a good course correction.
Keep reading.

Tracing out and documenting the wiring is one of the best things you can do now.

You're getting nailed from the helm? What's located there that is powered?
I'll bet there's nothing running on 110. If that's the case where is your DC and AC getting together?

At some point you're going to need a voltmeter. Go get one now.
And as always the plug in AC polarity tester is a must in this case.

It wouldn't surprise me a bit that you find the AC hot and neutral reversed somewhere. It is kinda counterintutive (at least to me) to put HOT on the black wire. So it's an easy mistake to make.