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Author Topic: Electrical current detected in and around boat  (Read 1565 times)

January 02, 2018, 04:10:18 PM
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daniel123

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Electrical current detected in and around boat
« on: January 02, 2018, 04:10:18 PM »
Using the Osprey 200 on vacation in SW FLA last week, where it was docked the entire week and placed on shore power to recharge the batteries each night, by day three we received slight electrical shocks when we rinsed our hands overboard or grabbed a pilchard from the bait well. I could eliminate the charge by switching the newly installed battery selector to off.

Also a couple of times during that period, the auto bilge pump, direct-wired to the starting battery, remained running regardless of the position of the manual bilge pump control switch at the helm -- even when there was no water in the bilge to trigger the auto sensor to turn it on/off. I'm thinking there is a ground issue? Or perhaps current is 'leaking' from the bilge pump's auto switch, which uses a water sensor to detect moisture and trigger the pump to on? What's more, at times the manual bilge pump switch on the dash would serve as an on/off switch for the livewell pump.(!) What's up with that?

Since the boat was last in saltwater, a year ago, we have installed a 2013 Evinrude E-Tec, replaced the wiring harness, installed a new water pump for the livewell, installed a Blue Seas on-board charger for the house and starting batteries under the helm, installed a new auto bilge pump switch in the bilge and 'cleaned up' the wiring under the helm console overall, including a new master ground connection. There is a light in the baitwell wired to the courtesy lights switch at the helm. Could that be the culprit? Any thoughts are welcome and appreciated.

January 02, 2018, 07:38:43 PM
Reply #1

RickK

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Re: Electrical current detected in and around boat
« Reply #1 on: January 02, 2018, 07:38:43 PM »
You mentioned that you get the tingle when it is connected to shore power.  Does it happen when disconnected?  The wiring in a boat is pretty simple - it consists of a negative reference from the battery (asks like a ground) and everything is connected to that including the engine. Does the engine have all the ground straps that are normal like between the bracket and the engine?
I'm thinking something is going on with faulty wiring on the shore power.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

January 03, 2018, 10:11:28 AM
Reply #2

daniel123

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Re: Electrical current detected in and around boat
« Reply #2 on: January 03, 2018, 10:11:28 AM »
Rick,

I did not test for shock when connected to shore power at the dock; we only noticed the stray current while out fishing and rinsing our hands overboard or grabbing bait by hand out of the well. I would actually be nervous about testing it while connected to shore power, as we received a sharp 'tingle' from battery power alone. 

Your point about the grounding strap on the outboard is worth investigating, since that is new to the boat. How do I cq that?   

Dan

January 03, 2018, 02:21:16 PM
Reply #3

RickK

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Re: Electrical current detected in and around boat
« Reply #3 on: January 03, 2018, 02:21:16 PM »
You hear of people getting shocked from badly grounded AC on docks - like when they are swimming and get close to the dock.
I personally haven't heard of people getting shocked within a 12V system. Yes, if you drop a wrench across the battery terminals but that's not usually done on the boat. Do you see this only when the engine is running?  Maybe there is a back-feed from the alternator on the engine (does an e-tec have an alternator?)
Look at the engine mount and you should see a braided strap attached (on mine it to 3 places) - mine was attached to the mount, the tiller arm and the lower unit.  That keeps everything at the same reference.
https://www.westmarine.com/WestAdvisor/Marine-Grounding-Systems
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

January 03, 2018, 02:54:34 PM
Reply #4

daniel123

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Re: Electrical current detected in and around boat
« Reply #4 on: January 03, 2018, 02:54:34 PM »
We experienced this when the engine was turned off and the boat drifting. On the occasions when I tested it I could eliminate the current in the water by turning the battery selector switch to off.

January 04, 2018, 05:45:14 AM
Reply #5

RickK

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Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

January 04, 2018, 09:17:06 AM
Reply #6

GoneFission

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Re: Electrical current detected in and around boat
« Reply #6 on: January 04, 2018, 09:17:06 AM »
It sounds like the AC power has the polarity reversed.  Check it out and get it fixed, because this can kill you!  Check your shore power connection and make sure the leads are correct.  Next, check the power cord and make sure both plugs are correct.  Electric shock drowning is a real threat - not just to you, but to anyone nearby in the water!  http://www.electricshockdrowning.org/ 
Cap'n John
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January 04, 2018, 09:19:45 AM
Reply #7

RickK

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Re: Electrical current detected in and around boat
« Reply #7 on: January 04, 2018, 09:19:45 AM »
Hi CJ,
He is getting shocked when not connected to shore power and motor is not running. Its weird for sure.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

January 04, 2018, 03:24:59 PM
Reply #8

daniel123

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Re: Electrical current detected in and around boat
« Reply #8 on: January 04, 2018, 03:24:59 PM »
Yes, this is happening on DC power (although it may be on AC/shore power too, I just never checked). I do not have an inverter.

The info you provided is helpful, especially the Boating article, which leads me to think it might be the bilge pump: The wiring for that can get/be wet in the bilge and the pump uses a switch with a water sensor rather than a float-type 'arm' switch to turn it on when moisture is detected across the face of the sensors. Plus, sometimes the pump would run regardless of there being no water in the bilge and whether or not I had the pump's manual helm switch turned on or off.

I'm guessing it's maybe a fault in the bilge wires, which are connected directly to the house battery, and could 'charge' the water around the boat, (via the bronze drain plug?) including the water in the baitwell since it is "connected" to the water around the boat via the thru-hull and the water in the hose between the well and the water? 

And the 'charged' water around the boat wasn't apparent all the time; it was worse after the boat had been used on the water all day and the deck was damp with spray or from landing fish and the bilge had been pumped a time or two. (We get some water sloshing onto the deck from the baitwell when it is full and the boat rocks; I suspect some of that water makes its way into the bilge and when there's enough it triggers the pump's auto switch when the boat is bow-high when getting on plane)

Dan

January 04, 2018, 03:51:08 PM
Reply #9

RickK

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Re: Electrical current detected in and around boat
« Reply #9 on: January 04, 2018, 03:51:08 PM »
turning the Batt sw to off stopped it though.  The BP is wired direct to batts so it shouldn't have had an impact unless it's feeding back when the switch is set to on.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

January 05, 2018, 11:03:50 AM
Reply #10

daniel123

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Re: Electrical current detected in and around boat
« Reply #10 on: January 05, 2018, 11:03:50 AM »
Good point, Rick. That would seem to eliminate the BP as the culprit.

I did a DIY wiring job to install a simple waterproof courtesy light to illuminate the baitwell. Since the baitwell water is also 'charged,' I'm wondering if that fitting might not be watertight and the source of the electrical current leak, which follows the water in the thru-hull to that which surrounds the boat. It appears I have a lot of electrical testing to do this spring to track this down. I hope I can do it effectively while the boat is on the trailer. Thanks for the help!   

January 05, 2018, 11:10:30 AM
Reply #11

fitz73222

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Re: Electrical current detected in and around boat
« Reply #11 on: January 05, 2018, 11:10:30 AM »
Keep an eye on your engine for massive amounts of corrosion and zinc degrade. With that current in the water, your engine is going to turn into an alkaseltzer tablet everytime you use it. Disconnect the baitwell light and see what happens.
1973 Aquasport 22-2, twin 115 Mercs
2000 Baycraft 175 flats boat, 60 Bigfoot Merc
1968 Boston Whaler 13, 25 Yamaha (project)
1966 Orlando Clipper 13, 9.9 Merc

January 05, 2018, 01:33:28 PM
Reply #12

wingtime

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Re: Electrical current detected in and around boat
« Reply #12 on: January 05, 2018, 01:33:28 PM »
I see you only get it when the engine is not running.  Keep in mind that unlike other outboards the Etec uses THREE different voltages.  56V, 14V and 5V.  The injectors and oil pump are 56 Volts when running.  Even when not running the EMM generates 30-40V when the key is on for starting.  This is not including the high voltages the stator and ignition coils produce.  So be careful around that thing.

As mentioned 12V DC is not known for causing the kind of shocks your getting.  I would start by looking at your onboard charger.  I suspect something is stepping up the voltage before it is leaked into the water.  Is is possible a bad diode in the charger is allowing the charger to act like an inverter or something.   Either way I would start by disconnecting anything new one at a time until the problem goes away.
1998 Explorer w/ Etec 250


1987 170 w/ Evinrude 90

January 05, 2018, 03:14:47 PM
Reply #13

daniel123

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Re: Electrical current detected in and around boat
« Reply #13 on: January 05, 2018, 03:14:47 PM »
I never actually checked for a shock when the engine was running; we only noticed it when drifting while casting with the motor off. I did install a new-model Blue Seas charger that is able to auto switch to charge both house and starting batteries off the motor and shore power. And I did notice the deep cycle house battery was dead when I tried to start off it alone, and had to use the battery switch on 'Both' to turn the engine over. That tell you anything? I'm wondering how I can test it properly without the boat being in saltwater to mimic the circumstances. I may not notice it as much in fresh water, and the nearest brine to float the boat is 10 hours away...!

January 05, 2018, 06:01:13 PM
Reply #14

RickK

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Re: Electrical current detected in and around boat
« Reply #14 on: January 05, 2018, 06:01:13 PM »
I'm glad some of the more experienced motorheads showed up - I was running out of ideas.  :whoo:  I didn't know the eTec generated that much voltage. Modern technology.
Capt. Bob tried to post (lost his connection) that if you stick your tongue across a 9V battery you'll get zapped, so it is possible with DC (I hope he didn't actually try that ;-) ).  So you may have a bare positive wire laying in water being pulled to the neg through you?

So you added a Blue seas ACR? I think I would disconnect anything you've added lately and see if the shock is still there, if not, connect one of the things you added and try again, etc.

This is interesting. If you discover what it is please be sure to come back and let us know.
Rick
1971 "170" with 115 Johnson (It's usable but not 100% finished)

1992 230 Explorer with 250 Yamaha

 

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