We had our boat hooked up to an AC power source while working aboard, on the hard in our cradle, and received a slight shock when handling the aft stern railings while getting onto the ladder. Was a clear sign we have some stray current or a ground fault. Your video was very timely.
Your experience with the ladder was similar to mine climbing on to the dock. And your ladder was probably grounded by itself with legs buried in gravel on the hard...
Not all countries, even in Europe, have a neutral leed. The best is to by an insulation transformer with a designated zero connection. Not certain that the whole Victron range is equipped with that. And then hook up the boat AC to a TT system. It should also be noted that cheap isolation transformers only block up to approx. 1.7 V. Anything above 1.7 V will float through and cause damage. It's a lot more to it :-)
You are correct that neutral isn't used in all AC power systems. North American 120/240 split phase is a common example as most north American homes are connected with two hot wires each at 120 making a 240 power an option for high-power things like dryers and stoves. But most homes worldwide normal sockets have a hot and neutral wire. And you are also correct not all isolation transformers will make a good choice for use aboard a boat. Best choose one like the Victron designed for use on boats. Definitely there is a lot to it. This video could have been an hour :-)
@@DistantShoresTV Yes. Well, Electro Engineer in Norway takes two years. But beware that you are building a boat that has a 'soft spot' for electrones on the run. That's why I empesize to hook up an AC system conforming to TT (mainly safety issues). And your DC should be a true 2-pole system. Choose motor with 2-pole brushless alternator. 2-pole switches on all system with DC electro motors with brushes, like bow thruster, winches, windlass and so forth. And a DC varning system for pos. leaks to the hull. I am not by profession an electrision. I have a degree in corrosion sience. Good Luck!
Thank you so much. I greatly enjoy your attention to detail, and I am encouraged to live better and with more intention as I see your passion and integrity.
I was barefoot and climbing off the bow holding on to the stainless pulpit fitting (which was bonded to ground). When my foot touched the aluminum of the dock I felt a very strong shock. I was temporarily a good path for AC electricity to run from the boat back to the dock where we were plugged in to the shore pedestal. This was back over 20 years ago on our original home-built 37 footer Two-Step. We had an inexpensive non-marine transformer to change AC 230V shorepower to 120V for our US style wiring aboard. I was very lucky I think!😳
Hey Paul. Nice explanation. Well presented. To add on your bonding true the prop shaft , that’s not the best way. They need to be grounded ( bonded) but to have a base plate nearer to the mast is way better. Obviously zink anode need to be present to in the bonding equation. An isolation transformer is not always need on smaller plastic boats. But these days the electric system are grown even on smaller boats.
Well explained, and gives me one more job to do. Thanks. The short up the mast clip makes me comment that I have recently come to the opinion that all metal edges at the mast head should be rounded. That mast cap is routinely a cut flat shape an the edges are left square. The problem with this is that the edge produces an electrical arc jump point when the body is subjected to an electrical field as with a lightning storm. The 90 degree angle represents 2 surfaces with a increasing electrical arc pressure towards the edge. A rounded surface has a uniform surface charge state making it more difficult for electrons to leave the surface. That is my thinking. My suggestion is that the mast cap plate should have rounded and even polished edges to reduce the risk of arc strike. I’ll be doing this to my mast head when the mast comes off soon to fit some new bits.
Great information about to re wire my vessel .. as she being rebuild .. your illustration and discussion makes much easy to come to terms with it .. than you .. from New Zealand
My 20 foot Paceship P2-20 is so simple electrically. All it has is an on board 12 volt DC system. That runs off of a 12 volt battery. I've never had to hook up to shore power as of yet. If I did it would just be an extension cord running to something specific on board. But there may come a time when I get a bigger boat. That's when this video will become important. Until now I couldn't have told you anything about more complicated sailboat electrical systems! Thanks for providing this information for possible future use! From what I have read you will be at the US Sailboat Show. : - D I hope to see you there! Distant Shores IV should be finished or close to it by then. PS - On Tuesday the 22nd of August I went out for my first sail of the year! I can't believe it took this long. I sailed for 2 hrs 5 minutes on Keuka Lake here in central New York State. It was close to ideal conditions. : - )
FYI if you do run an extension cord aboard it is just like standing in the shower holding a hair dryer. I would definitely be careful and at the very least make sure the extension cord was going through an ELCI or GFI outlet (that you had tested first by pressing the test button)
@DistantShoresTV Thanks for that information! So far the only time I've had 120 AC on my boat is when it's in my driveway getting leaves vacuumed out of the cockpit. : - )
Greetings, I have enjoyed seeing your boat develop. Many great ideas. I have mentally designed a 50’ modern aluminum hull expedition boat with twin screws for maneuvering and junk rigged sails. With center wheel house/ bridge and large weather proof deck house aft. How do you prevent condensation inside an aluminum boat? I have seen where Boreal sprays a coat of cork on the interior. Does that include the overhead? I hope when you get to the interior you do not gloss over the insulation to block heat and cold. I am also very curious how you will mount electrical, plumbing, lightening protection etc out of sight while keeping it accessible for maintenance and repair. I like the hybrid power system. Have you seen the Sharrow toroidal Propeller?
Very informative. I knew of the issue from a Kiwi boat electrician friend who's main work was re wiring old and new boats. He explained the main reason you can not swim in a marina is electrocution. Most all boats leak juice. Now I understand this a good bit more. My sense is the 'Isolation Transformer' thing should generate heat if under a strong load.... Would this be correct? Your new boat looks just fine!
Google will find it. So long as you state which country/continent, as rules are slightly different between Europe and North America. Also checkout Pacific Yacht Systems, very informative site.
Thanks for another good video. Since you are planning sailing to Norway beware that we are usually using 230v IT net system, not TN net system like the rest of Europa. This shold not affect safety, but could affect the efficiency of charging your hybride system. Best regards from a Norwegian sailor.
This is a most excellent video about electrical grounding of AC & DC systems on an aluminum SV, both from the standpoint of personnel safety and galvanic safety.! I served on a nuclear submarine and one useful system we utilized was a “ground detection” system. It monitored the AC & DC electrical systems for grounds. Once a ground was detected there was a procedure to sequentially isolate sub-panels, then finally individual circuits to locate and repair the ground fault. Does Victron or some other vendor offer a similar solution? Finally a trivial question: I own two Tilly hate for sailing but admire your model with the narrower brim for more urban settings. What is the model number? I’ve scoured the Tilly site but cannot find it. Thanks, I can’t weight for your upcoming video for the electric-hybrid propulsion installation. 😎
Thanks @vincentstouter449 - glad you enjoyed the video... I am not aware of an installed system that checks ground potential. I checked and my hat is an "LTM5 Airflo Hat" by Tilley :-)
I guess you are talking about a boat with an isolation transformer. In that case you can choose to ground the neutral output to the boat and connect an RCD, or NOT connect neutral to ground and connect a Low resistance to ground detection device.
@@DistantShoresTV Thanks 🙏 so much for such a timely reply, Paul. Subs extensive electrical systems, both AC, of multiple frequencies and voltages ,DC, of multiple voltages, and large DC motors resulted in ground mitigation being an important concern. While not made of aluminum, galvanic and electrolytic corrosion as well as personnel and equipment safety and reliability were always items of concern. We employed AC & DC ground detection systems, as well as equipment like shaft grounding devices to resolve grounds once they were detected because metal wasting could occur at an accelerated rate when there was a ground and current flow (not good for a pressure hull 🤣). I really admire the attention to detail that both you and the yard are exercising for this build. Since the propulsion will be a parallel electric hybrid, ground protection will be even more important. The insulation, painted surfaces, galvanic isolators and isolation transformer all work together to produce a reliable yacht. Thanks also for the Tilly info. 😎
Presumably all this knowledge has come about whilst you're building your aluminium yacht - I'd imagine that the modern equipment make corrosion of the aluminium much less likely than it used to be?
North America is 120v, most of the rest of the world is 230v. To be compatible with both I’m looking for an isolation transformer that is also a 1:2 step-up. Any suggestions?
Saved video in my blue water small boat file for reference when I get going hopefully July 2025.i must have watched over the last three years almost all videos to do with small boat sea fairers.
Why in the graphic for the Isolation Transformer is the current depicted as flowing from the charger/inverter (the boat) TO the transformer (the new power source) along the hot wire? I’d think it should be depicted as flowing the other direction?
My 120VAC ground is not connected to the DC ground at the engine and the prop shaft has the polyurethane isolation puck. So it would be almost impossible to get an AC or DC leak to the water. I have a device that gives me a visual indication if the AC ground fails to the shore pedestal. However, a device that has a sound warning of the AC ground failure would be most ideal but have not been able to locate such a device. Boat is fibreglass in fresh water.
In my area we removed the ground cable, and therefor not bringing the ground in the boat - how does that effect the system? Still have a internal grond onboard via the steel hull. Also how does grounding work then out sailing and running via the inveter? But nice vid
The purpose of the ground is to provide a safe path in the even of a ground fault so I don't think would be a safe configuration... I hope there is at least an RCD or ELCI device at the shore power pedestal to try to guard against such a ground fault. RCD or ELCI must be tested regularly (monthly) by pressing the test button to prove they are still working. If they fail It is my understanding that they might keep passing current but NOT be protecting against faults. In that case your situation could be dangerous with no ground wire. Have you had electricians look at your installation?
@@DistantShoresTV thx a lot for the reply! It's an marine electrician that's made the system. I know there is ground on the shore, but my shorepower only have two wires, phase and neutral, and therefor not bringing the ground wire onboard. But when shorepower iscoming inside, it's runs though an rcf, then though the combi inverter, then back to yet another rcf that then splits into two 10 amps fuses. When I press the test button onboard the rcf does works however, and the ground to the rcf is connected to the steel of the boat. But not to sure how that effects corrosion
Hi Neil! GFI have a lower fault tolerance normally 5mA and are used in the galley or heads or other wet spaces. They trip quite easily at just 5mA whereas an ELCI or RCD trip at 30mA and are normally used to protect the whole boat or whole house. So we will have an ELCI at the power input to boat then individual GRI in each heads and galley.
thats not completely correct, but a good rule of thumb.. military uses 24 volts and civilians use 12 volts.. 24 volts can hurt you but 36 can kill you.. many debate the 24 volts.. stick with 12 volts and an isolation transformer
I think modern transformers are over 95% efficient but I couldn't find a definitive number. Here is the link to the Victron units we're looking at. www.victronenergy.com/isolation-transformers/
With only 12v there would be no where to place the isolator. But I think there is a hack where you connect a wire to the battery negative and to a big electrode in the water. This would limit galvanic currents through your driveshaft and thus make your driveshaft anodes live longer.
My understanding is that a “hot” part of a boat in the water is dangerous in fresh water, because the human body conducts better than fresh water. Conversely, seawater conducts better than the human body, so a leaking current does not flow through the person. Comments from those more knowledgeable would be welcome
I think there have been cases in brackish water. It would be difficult to judge where in the Chesapeake Bay would switch over from "safe" to "annoying" to "dangerous" to swim in a marina.
Are you getting a lot of ads through RU-vid, Chris, or do you mean the updates we give about upcoming events we're involved with? Just curious since we wont to give all our viewers a great experience.
I have sailed well over 100,000 miles over 34 years. Luckily I have been seriously shocked only once. I have seen many problems with unsafe wiring for shore power - warn out cords dangling in the water and shore power plugs burned. I made the video to try and help people understand how shore power works.
@@DistantShoresTV like you I have sailed many years , many many marinas , lots of electric issues , in different countries , no shocks , none of my crew have had one , no £££££££ box to save us all, neither have you , would you tell everybody to not go sailing until they have all this £££££ equipment . Scare mongering . You used to be be daring get out there , sad day
