You probably don't NEED to know this, but it's interesting, and one of those things that one day you may actually benefit from the knowledge, and not necessarily even in relation to anything nautical.
There's a surprising amount of electrical science behind the simple concept of a boat floating in the sea. But when they hook up to shore power then things can get really bad if they don't have a simple device called a galvanic isolator fitted in the ground/earth wire.
This video explores the science and shows how a simple galvanic isolator is made.
If you enjoy this channel you can help support it with a dollar for coffee, cookies and galvanically exciting gadgets at https://www.patreon.com/bigclive
There's a surprising amount of electrical science behind the simple concept of a boat floating in the sea. But when they hook up to shore power then things can get really bad if they don't have a simple device called a galvanic isolator fitted in the ground/earth wire.
This video explores the science and shows how a simple galvanic isolator is made.
If you enjoy this channel you can help support it with a dollar for coffee, cookies and galvanically exciting gadgets at https://www.patreon.com/bigclive
Is there any damage caused by having too much AC on your ground line or is the time delay from that plating/unplating effect protecting everything.
In Finland heating pipes are steel pipes so that the connection to a radiator is not two different metals. Water pipes (even warm water) are usually copper pipes though.
Big Dude, how would the Mannanan fair as it is Aluminium isn't it? TFS, GB 🙂
Very interesting Clive. I am currently having a narrowboat built which we will be living on permanently in an inland marina. The boat will have both sacrificial anodes and a 'Sterling' galvanic isolator. Although I did have a very basic understanding of the rationale, thank you for creating this video and explaining in detail. You are absolutely right, the day has come where I need to get to grips with this stuff!!!!!!!!!!
Nice one Clive, I am used to working on industrial electrics (ex.Instrument Tech.) I came across this problem recently when I put my boat in a Marina, I originally thought of isolating the transformer but some research led me to the galvanic isolator idea, the only problem with this setup is if the diodes fail they fail open and you lose your earth, this would be very unlikely as the rcd should trip on earth fault also, so are we looking at the different potential on earth here? the earth is bonded to the metal on the boat and that, in turn, is bonded to the sacrificial anodes. if this is the case you would always have a small current flow because of earth bonding. ?
Marina just cancelled my order as "you won't need it, electrician said, you could get the £2000 full isolation unit instead…"
I just bought one off Amazon instead. Oh well.
PS I doubt you could test these as they are often potted/epoxied for safety and water protection.
Serious question I had for years: is it possible to use this metchod to prevent road vechiles from rust? If yes, I would definetly put bar of zinc under my car.
Well, I learn something new every day watching this channel – even as a professional electronic engineer. In this case though, I realised he was going to use diodes before he said so. But I would never have thought of the solution had he not introduced the problem in the way he did.
It's crazy that I had to go back to a video from 2016 from someone who basically never talks about boats to find this information. I kinda wish there were people in the youtube boating space that talked about stuff this in depth.
Well, what if you bridged the DC side with a really big (many ohms) resistor?
The same thing happens in car engines that have iron blocks with aluminum heads and aluminum radiators.
What an elegant and simple solution with those diodes.
When hooked up to the positive terminal of the power supply, you are pulling electrons out of the metal, causing it to corrode. That is why it appears cleaner.
When hooked up to the negative terminal, then it start plating from the solution, then once the solution is depleted so it can't plate any more, it starts reacting with the electrolyte/water