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Posts: 2024
| So something weird has started happening the last few weeks (that I've noticed at least). Here's the situation.
We keep the boat in our garage and plug the charger into an extension cord running from the boat to an outlet in the garage. We just recently put in some new Trojan AGM batteries as well as a new battery charger. Now, when the charger is plugged in and you lean against the gunwales (aluminum boat) you get a shock 9 times out of ten.
Thoughts? Does it sound like a short or connection problem? I'm beyond dumb when it comes to anything electrical. |
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Posts: 1462
Location: Davenport, IA | I remember the instructions on my minn kota charger said not to mount it to aluminum or even have screws/bolts touch it. I screwed in a board and screwed the charger to the board (w/ different screws). |
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Posts: 2024
| Thanks, Zach. I'll try that and see what happens. |
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Posts: 2112
Location: The Sportsman, home, or out on the water | Schuler - 9/25/2007 12:03 AM
I remember the instructions on my minn kota charger said not to mount it to aluminum or even have screws/bolts touch it. I screwed in a board and screwed the charger to the board (w/ different screws).
My folks had a winnebago that had the same problem when I set up the jackstands on a campsite. no wonder why I'm so mental. lol |
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Posts: 2754
Location: Mauston, Wisconsin | You have a very dangerous situation! You or anyone else touching the boat could be killed! First & foremost there is either a fault in the charger, a wiring problem or both. Usually the latter. Have you tested the electrical outlet with an outlet tester? What about your extension cord? Lastly recheck the charger wiring/installation. You can get an outlet tester at most hardware stores. I'm guessing something is wrong with the grounding in the power circuit, i.e., what electrician's call the equipment grounding conductor, a.k.a. "the green ground wire".
Isolating/insulating the charger is not a good solution, i.e., you will still have a problem. Call me if you need more help-> 608-847-6123
Al
Edited by ESOX Maniac 9/25/2007 6:41 AM
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Posts: 5874
| My first thought is that you have worn through one of your conductors on the AC supply to the charger, and this is now making contact with the hull of the boat, and that is causing the shock. Do you have a receptacle on the boat that you plug in to? Or just a pigtail off the charger? IIf the former, I would check the cord from the receptacle to the charger very carefully for a worn spot, especially where it goes through a bulkhead, or other potentially sharp edge.
It is possible the charger need to be isolated from the aluminum of the hull. I'll try to look at a manual, if I can find one. You could try to call Minn Kota tech support. |
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| ESOX Maniac, please explain how this is a very dangerous situation. My last boat did this all the time, and my new boat does too. I believe it is nothing more than feedback thru the boat as I have both onboard chargers bolted directly to aluminum bulkheads. It's not so much a shock as it is a little electrical charge felt when leaning against the gunnels. But I want to be sure everything is ok. Please let me know. |
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Posts: 1086
| smally,
Personally, myself, if I was experiencing something like this described above...I'd be concerned being there could be some gas fumes from the on-board gas tank in the boat that could ignite and blow everything near it sky high. An electrical charge that's shocking someone is in essence creating a small spark....which...if the boat's enclosed in a garage and not exposed to open air or fresh air...if fumes built up....could be a recipe for big trouble.
My on-board battery chargers are mounted to a fixed piece of wood that's been designed and installed purposefully from the factory to have the batter chargers mounted to as well as the cranking battery as well as my boat's oil injection resevoir. |
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Location: Athens, Ohio | If you have 110 current bleeding onto the hull and into your body, that is for sure a dangerous situation. Read Al's post carefully, he knows about what he speaks. m |
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Posts: 2754
Location: Mauston, Wisconsin | As I said there are likely two things happening simaltaneously.
# 1. There is a problem with the safety ground (equipment grounding conductor path) a.k.a. the green wire. Either it's missing or it's open. This problem could be anywhere in the circuit, including in your house wiring - Therefore, check the outlet you are plugging into with an electrical outlet tester.. and
#2. There has to be some type of fault that is energizing the boat hull..as Shep also suggested. This could be anything including the charger itself (internal fault).
The only good reason that I can think of for isolating the charger from the hull would be to prevent galvanic corrosion of the hull...... In this case isolating it will just give a false sense of security, i.e., the charger metal case itself could still be energized/a shock hazard if the fault is internal to the charger. Is this charger UL listed?
Yeah- a little tingle may or may not kill you. But given the right circumstances, you'll still be dead. Also keep in mind that when it comes to electrical shock currents the smaller your body mass the more suceptable you are. What just shocks a 250lb man can kill a 50lb child.
Al Warner |
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Posts: 2754
Location: Mauston, Wisconsin | addendum: For those interested "galvanic corrosion" is caused by DC current not AC current.
Here's some basic info-> http://www.cdc.gov/elcosh/docs/d0400/d000467/d000467.html
Al
Edited by ESOX Maniac 9/25/2007 12:26 PM
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| OK, I hear what everyone is saying. Now, what do I do about it. I know for a fact that both chargers are functioning 100% correct. I know for fact that I have no exposed wires touching anything. I know that I'm not plugged into a GFCI outlet. what I don't know is if the outlet is even grouded. If not could that be my issue, and how do I check for this. Please help as I want to be safe obviously. I just never thought it odd since this has been going on for 10 years thru 2 boats. |
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Posts: 2754
Location: Mauston, Wisconsin | ESOX50 & smally- To address both of your problems-> First check the wall outlet with an electrical outlet tester (I've already said this twice). However, answer these quick questions.
Is the outlet you're plugging into 3 prong or 2 prong?
Same question about your extension cord (both ends). Are they 3 prong or 2 prong?
Are you using a 3 prong to 2 prong "cheater adapter"?
Al |
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| Got to the hardware store and pick up a tester, it will show if you have a properly wired outlet, no ground, reverse polarity, etc.
I strongly suggest you and everyone else reading this either change the/your receptacle to GFCI or purchas a GCFI pig-tail to plug into. All 110v in your garage or outdoor-power should be GFCI protected.
I don't have time to go into it all...BUT, What AL says is valid. Even small amounts of current of 110v in small amperages can stop the human heart of an adult if it passes through your body in the right/wrong way. All it takes is for the human body to be properly grounded (wet shoes, no shoes, etc). Less than 25 mili-amp and "mili" means thousanth of one amp to do some serious damage to the human body! Properly operating GFCI will open if there is between a 5-8 Miliamp difference in outgoing and returning current.
In my day-job I am the Safety Director for a large construction company, I have a bit of experience in electrical safety.
And IMHO, you should NEVER EVER feel current or anything similar in your aluminum or glass boat if everything is properly wired and in operating correctly.
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| ESOX Maniac. At my house I'm using the cheater adapter. At my cottage which is brand new I'm sure everything is properly grounded (not GFCI though). I can't remember if I get the static feedback when I plug at the cottage or not. I will check on this when I get up there next, but I want to say that it happens there too. Is the cheater adapter the problem? |
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Posts: 2754
Location: Mauston, Wisconsin | K-guys a quick lesson in power electronics. If your house was built with 2-prong outlets, it wasn't designed for today's electronic loads- this includes electronic battery chargers. All electronic loads, i.e., your computer, your boat battery charger, your TV, etc. have what we power electronics/electrical engineers ( guys like myself) call EMI/RFI filters in them. These filters frequently have what we call "leakage current" to chassis ground. This leakage current is limited by design and accepted industry standards to small values, i.e., 1 mA or less in most cases.
This is not a problem if the green safety ground/equipment grounding conductor is present in the supply circuit. Thus, the equipment (your charger) comes with a 3 conductor power cord and a 3-prong power plug at the supply end.
smally - Now the issue at hand. Is the charger defective? Probably not! What is defective is the absence of the equipment grounding conductor path back to the supply source.
These 2 prong to 3 prong cheater adapters frequently have an green wire or a terminal that is suppose to attach to the supply receptacle ground via a screw connection. If the wire is not attached or the adapter or the receptacle is not grounded there is a safety issue because of a lack of the safety ground path. Then, what's likely happening is you physically are becoming the leakage current path back to the source when you touch the boat. All electrical egineers know about this phenomena, i.e., Kirchhoff's law of currents.
Guess what over time EMI/RFI filters also deteriorate, i.e., the leakage current can increase to a point where the circuit breaker or fuse opens. However, this is action is also predicated on the fact you have a solidly connected equipment grounding conductor (green wire) path back to the source. In the case of a "compromised" safety grounding path, you have a potentially lethal situation. Is the manufacturer liabel? No, you are because you are not using the product as intended!
What can you do to protect yourself, your family and others? Follow Curley's advice. Get a extension cord with GFI protection. Then you might not wind up dead. Better yet have an licensed electrician install a GFI receptacle. You still might get shocked. The only real way to really protect yourself and your family/friends is to have the electrician install an 3-wire circuit and 3-prong outlet. Even then the outlet has to be GFI to meet current National Electrical Code for outside or garage receptacles.
Al
Edited by ESOX Maniac 9/25/2007 6:26 PM
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Posts: 2024
| Hmm, it appears I had a bigger problem than expected! Just went out to the boat a little bit ago and couldn't feel a thing. Went inside, came back out again, touched the boat and felt a little shock.
Al and all, thanks for the responses. I really appreciate it. I've bookmarked this thread so when (hopefully this weekend) I find a spare couple hours I will do some digging and try to correct the problem.
I did notice the charger (Pro Mariner) was installed directly onto the aluminum of the boat, I might try and separate the two. I will take apart the charger and look at the grounding too, and test out the outlets. |
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Posts: 2754
Location: Mauston, Wisconsin | esox50 - This is just a WAG (wild a$$ guess) based on the every limited information from you.
First- don't disassemble the charger. Doing that would quite likely void the manufacturer's warranty and/or you might create a new problem.
Second - Please understand that the great unknown here is the wiring in your house. If your house is very old, i.e. circa late 1800's to early 1900's and you could have "knob & tube" wiring you will need an electrician, However, I might be able to provide some addition guidance. Answer these questions
1. Is your outlet 3-prong? If yes go to question #4.
2. If your outlet is 2-prong. Are you using a 3-prong to 2-prong adapter at the outlet?
See these->
http://electronics.howstuffworks.com/question110.htm
http://www.gov.ns.ca/enla/electricalsafety/esbadapterplugs.asp
3. If you are using a 3-prong to 2-prong adapter. Is the adapter connected to the outlet cover plate mounting screw? If not- connect it!
4. Go buy an electrical oulet/circuit tester, i.e., the kind with the indicating lights. (besides it a good thing to have around the house- mine travels with me on fishing trips) If you plug the electrical outlet/circuit tester into the 3-prong outlet or the 3-prong to 2-prong adapter at the 2-prong outlet. Does it indicate the outlet is properly wired?
If the outlet/circuit tester indicates a problem, you need the services of a licensed electrician.
5. Are you using a 3-prong extension cord? If not, go buy one!
6. If your extension cord is 3-prong. Is the male plug grounding pin intact (meaning it hasn't been cut or broken off)? If the grounding pin is missing go buy a new 3-prong extension cord. If you are mechanically/electrically inclined you might be able to replace the broken plug with a new 3 prong plug. If you are unsure as to how to do that-ask the guy/gal at the hardware store.
If you get this far and the problem is still there, you need an licensed electrician.
Because we are talking about safety. It's also a very good idea to buy a GFI extension cord for the boat, i.e., for your and everyone else's safety. Who know's if the dock outlets are properly grounded at that resort where you're staying.
http://www.lsuagcenter.com/en/lawn_garden/commercial_horticulture/e...
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| Al, thanks for all your good insight into this issue. I will be taking the corrective measures immediately. My chargers are also the Pro Mariners. The installation directions said nothing about not mounting the chargers directly to an aluminum bulkhead. Will a GFI extension chord plugged into an open ground recepticle (2 prong) be okay ? |
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Posts: 2754
Location: Mauston, Wisconsin | Yes- that will protect you from electrocution. However, it will not likely stop the low level shock's. The only way to do that would be to have an electrician rewire the circuit to a solidly grounded 3-wire/3-prong circuit. Of course the National Electrical Code would require him/her to install a 3-prong GFI receptacle.
Al |
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