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AstoriaDave
Joined: 31 Oct 2005 Posts: 994 City/Region: Astoria
State or Province: OR
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thataway
Joined: 02 Nov 2003 Posts: 20778 City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
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Posted: Thu May 05, 2016 2:21 pm Post subject: |
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Dave, Thank you!
A very important issue--and it is unusual, but extremely serious when the death occurs from electrical current transmitted thru the water.
The article seems to imply that this mostly occurs in fresh water, but it can occur in both salt and brackish water.
One of my objections is that the illustration and method of testing, relies on the power pedestal being the culprit. It is often the boat which is miss wired. So when checking for the proper wiring, the boat should be checked also.
Also there are some issues using a clamp on meter to measure the current where this may not show leaks, especially if it is an adjacent boat, or an adjacent boat with bad wiring. So be aware of not just your boat.
In my boat, I float the ground, and the only potential contact between the AC system is potentially the battery charger. So that should be looked at, as well. I put a ground fault interrupter in the extension cord (I only use 15 amp cords--where most of the C Dory built in 110 V systems use 30 amps.
This way you are protecting the boat before the power panel, instead of just a few plugs.
At my own docks, I put in a ground rod right by the dock power pole, since I have found as much as 2 volt differential due to a long run in the conduit or power un under the dock. (most docks do not have that luxury).
Probably the best advice is to not swim in marinas!
Here is another Boat US publication Which shows in more details the issues, and another way to test using a single copper plate as a test wand.
The device: Ideal Sure test Circuit Analyzer is about $350; But you can do all of that with a $45 Craftsman clamp on volt meter (which should be part of the electrical kit, and a $6 LED 15 amp circuit tester.
[/img] _________________ Bob Austin
Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018 to Oct. 2021
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
Frequent Sea; 2003 C D 25, 2007 thru 2009
KA6PKB
Home port: Pensacola FL |
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colbysmith
Joined: 02 Oct 2011 Posts: 4523 City/Region: Madison
State or Province: WI
C-Dory Year: 2009
C-Dory Model: 25 Cruiser
Vessel Name: C-Traveler
Photos: C-Traveler and Midnight-Flyer
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Posted: Thu May 05, 2016 6:16 pm Post subject: |
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How many folks leave their power cords lay on the dock, still plugged in and turned on when they go out for a cruise? I have gotten in the habit that I turn the power box off, before plugging my cord into it, and then I turn it back on after my cord is hooked up at the boat. Unplugging, I turn the power box off before removing the cord from my boat. Glad I got into this habit. One time the cord fell into the water as I was placing it on the dock from the boat. I also don't swim in marinas, or places where boats are plugged in. Of course there are the issues of generators... Colby |
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thataway
Joined: 02 Nov 2003 Posts: 20778 City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
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Posted: Thu May 05, 2016 6:56 pm Post subject: |
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The generator is subject to different problems. Some generators are grounded, and some are not--most built in are grounded to the boat's floating ground system. They are not grounded to EARTH...that is an important concept to remember.
The 110 V mains power, is actually physically grounded with a rod pounded into the ground. There should be a galvanic isolator or isolation transformer at the ground system to the boat. The generator is on the boat circuit side of the isolation transformer or galvanic isolator.
Yes you can be electrocuted by a 120 volt generator. But this would between two sides of the generator power. If there is a neutral or ground to water, and you had power from the 3rd (black) wire, then there could be a circuit and "zot".
There as a story that John Wayne' had lost a Boston Whaler from Wild Goose in Acapulco. That he then hooked up his 110 V one side to the railing of another Boston Whaler in the water, and the other side of the circuit left in the water. One dead Mexican floating in the bay= no more thefts of Boston Whaler. You say cruel? Certainly. However, one night in Acapulco my dog awoke me, I got on deck, and saw a local stealing a dinghy. I hit the air horn, turned on spreader lights, spotlighted the dinghy thief, yelling "Dinghy Thief". Immediately one of the 18 year olds "Federalae" guards at the Acapulco yacht club opened fire at the dinghy with his AR 15! I turned off the lights--the thief swam away, and I corralled the dinghy and took it to its owner... |
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hardee
Joined: 30 Oct 2006 Posts: 12632 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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Posted: Fri May 06, 2016 5:24 am Post subject: |
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Good article Dave, Thanks for bringing it up. I was just reading a similar article in another boating magazine. something we should all be aware of, especially if we plug in to the marina power or are ever tempted to swim in a marina.
Harvey
SleepyC
_________________ Though in our sleep we are not conscious of our activity or surroundings, we should not, in our wakefulness, be unconscious of our sleep. |
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hardee
Joined: 30 Oct 2006 Posts: 12632 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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hardee
Joined: 30 Oct 2006 Posts: 12632 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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Posted: Fri May 06, 2016 2:10 pm Post subject: |
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I can't get rid of that " " in front of "SleepyC" on that post. It does not show in the text when I try to edit.
Just in case you are wondering, "I" am not Sleepy.
Harvey
[i]SleepyC
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hardee
Joined: 30 Oct 2006 Posts: 12632 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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Posted: Fri May 06, 2016 2:11 pm Post subject: |
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Now it happened again.
Harvey
SleepyC
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hardee
Joined: 30 Oct 2006 Posts: 12632 City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
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Posted: Fri May 06, 2016 2:12 pm Post subject: |
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Sorry for the multiple tries. I think I know what it is now.
Harvey
SleepyC
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