Electrical shock

[simpsonc]

I Have a hunter 41 AC 2005
No problems noted until I got a call from my diver who cleaned the hull. He gripped the propeller shaft and got a shock.

Not sure if this is from the boat or the marina where we are settled for hurricane season.

I need advice where to start.

 

[Stu Jackson]

Sorry to hear about your problem.

Buy Nigel Calder's Boatowners Manual for Mechanical and Electrical Systems.

Really, great writeup on electrical systems and marina wiring. You could also do a Google search on the issues: AC systems on boats and marina wiring.

Again, really, this is much too complicated an area to discuss here, they've written books about it, and too long to retype.

We don't know if you were plugged in or not. We have NO idea what condition your electrical system is in. We have no idea where you keep your boat or what condition the marina wiring is in. We don''t know if your AC and DC systems are grounded together. We don't know if you have a galvanic isolator or and isolation transformer.

These are things we need to know first.

All that information could help us to help you, but you might want to consider doing some homework and research first on this relatively complicated subject.

You could go here:

http://www.westmarine.com/WestAdvisor/West-Advisor-Articles

And scroll down to electrical and do some reading, includes good books, too. Charlie Wing's is a good one, too.

You did ask for a "place to start", right?

 

[Chuckbear]

This could be a problem with the boat and could be a problem with the shore power. I would check the shore power before taking the boats electrical apart. We ALWAYS unplug the boat from the dock when a diver is in the water working on the bottom. If you don't know how to do this and don't have the equipment, get a professional. Don't ask the marina to do it. Chuck

 

[Sailvayu]

It sounds like you have an AC leak to ground. The most likely cause is a short in an appliance aboard the boat. Of all the appliances I have found trouble with the water heater is at the top of the list. That said checking this requires a systematic approach starting at the shore power and working into the boat. If you do not have solid knowledge of electrical trouble shooting I strongly recommend you get a professional to find the problem. This could be a dangerous situation and it is best to get help from someone who knows their stuff. Stu Jackson is right this is not something that will likely be solved here despite well meaning advice.

 

[Bill Roosa]

your dang lucky that your diver is not dead. Clearly he is passing current from/to the propshaft. shafts are intended to be at ground potential by either being unbonded or through the engine ground. Clearly it is not unbonded and engine ground problems would manifest other problems so he is passing current to the propshaft. Something is live in the water. Given the, thank the good Lord, that the diver is not dead I'd be willing to bet that it is dc and not ac current. Likely candidates are your bilge pump, another boat's bilge pump, another boat's faulty grounding circuit, marina hot/neutral wired backward.......
First thing to check: is your propshaft at ground potential. volt meter between the shaft (inside) and engine ground should show 0 volts. Next ground a volt meter to the propshaft inside the boat and the other probe gets dipped in the water of the bilge. Should also show 0 volts.

 

[Stu Jackson]

See, it's not so easy to diagnose. One skipper says it's AC the other says DC. You can either learn about it and deal with it, or find an electrician. Since you're on the move, you have the other choice of simply disconnecting from shorepower while you learn or look over the guy's shoulder.

Good luck.

 

[rgranger]

... and it might not even be your boat that is the problem.

 

[Bill Murray]

Stu is Right! people have died because of similar situations. It is called Electric Shock Drowning (ESD)

If you are not aware of this... read http://www.boatus.com/seaworthy/ESD.asp

Do not let people swim in your marinas!

 

[shemandr]

I've never read a more through and clear explanation as Ms. Leonard offered. I did not understand until reading it, how little AC electricity it can take to stop a heart.

 

[LloydB]

"Not sure if this is from the boat or the marina where we are settled for hurricane season."
1 start yesterday
2 accuse the marina and document the call
3 make sure
just wondering, if he had said 'when I walked past the companionway hatch I smelled smoke' would you be trying to figure this out on the internet?

 

[walt]

For the OP, did this (diver getting a shock) occur in fresh or salt water?

I believe the same "leak" could produce only a shock in salt water but could be very dangerous in fresh water.

I think I would get one of the those instruments that verifies AC hot, neutral and ground connections are correct and test the whole "line" starting with the AC the marina is supplying you.