galvanic isolator, which one? 16amp or 32amp

[s/v Jedi]

No, a US 50A shore power is normally a 120/240 50A for a total of 12kW.

The 7kW is for a 230V 32A shore power feed. It’s not for 120V but you can use it for 240V as long as you stay under 30A.

So just that you know: if a US setup boat takes 240V with the 3.6kW transformer then you get either 120V or 240V, not both. For that you need to use a 230V Multiplus and add the autotransformer as shown in my reference diagrams.

[Sailorlou]

s/v Jedi - Your solution is Correct. I was just referencing the units that Victron have. They don't have a 120/240 Volt 50 Amp Isolation Transformer.

[YANDINA]

Smart Shore Marine has a 50 amp failsafe Galvanic Isolator on sale for the price of a 30 amp.

[boatpoker]

Originally Posted by YANDINA

Smart Shore Marine has a 50 amp failsafe Galvanic Isolator on sale for the price of a 30 amp.

1. Poster does not acknowledge working for that vendor.

2. OP claims it to be "failsafe" but it has no means of monitoring, as required by ABYC to meet the "failsafe" requirement.

2. Claims to Meet ABYC but is not tested by an independent lab. i.e. UL.

3. Website claims it blocks "electrolysis" but don't understand that in "electrolysis" the cathode is negative and the anode is positive (the exact opposite of galvanic corrosion current).

[Cheyne]

We have a 3 burner induction cook top, electric convection oven, Ninja air fryer and other assorted electric cooking devices. Being at the dock isn’t that common for us, except during the summer when we prep to go back to the Bahamas. We have a 1600 amp hour house bank and depending if we are moving or anchored 3000w or 3500w of solar. The extra is from portable panels we put on our trampoline when on anchor. The only propane we use is the little green bottles for our grill.

Cheyne

Originally Posted by Sailorlou

Why do you draw 4500 Watts when cooking? Do you have an electric stove? It's rare to see an electric stove on a 40 foot sailboat.

[s/v Jedi]

For the amount of power available for use aboard:

My strong recommendation is that you should be able to use your appliances while NOT connected to shore power. We are boats and are supposed to move about fully operational, not limping from dock to dock.

This means you need the inverter power to run the show. The Multiplus 3000 rules this and for good reason. If you have a full electric galley, you will find that it isn’t enough and for that I recommend to install two Multiplus 3000’s instead of a larger Quattro 5000. This for many reasons outside the scope of this thread but let me mention more power, redundancy, frequency conversion etc. See my threads with reference diagrams for details.

Once you have the inverter power, you need to find a source for that power. This can be a generator, a large solar array, a big alternator and also shore power. But all those sources are only available part time. This means you need a battery to store energy as well.

We all know everything I wrote above. But many don’t realize that your power sources (genset, solar, shore power) don’t need the amount of power for your peak usage! You only need the average power usage, while using the battery for peaks.

With the Victron Multiplus and Quattro lines, this is done automatically and called PowerAssist. In this thread we talk about shore power so let’s take that as an example: let’s say you have peaks where you use 5kW but you only have a 3.6kW shore power with the Victron 3.6kW isolation transformer. This can be a European 230V 16A service or an American 120V 30A service.

In the settings you program your Multiplus or Quattro that it may only use 3.6kW of shore power and you enable PowerAssist. If you have two Multiplus 3000’s, which combined can do 5kW sustained, you get a total of 5 + 3.6 = 8.6kW !!

How this works: the Victron unit(s) take up to 3.6kW from shore. If less power is used, the rest goes into battery charging. If power use increases, charging decreases to keep things under 3.6kW. Now if power use exceeds 3.6kW, the Victron units start taking power from the battery, inverting it and are able to ADD it to the 3.6kW from shore.

So you see that when you can run your boat on inverter, your shore power as well as genset don’t have to be able to run the boat; they only have to be able to supply the average use so that the battery isn’t drained.

For battery, my experiments have shown that a 10kWh battery capacity provides a comfortable boat with full electric galley, electric watermaker and even allow occasional A/C use. You could do with 8kWh when you skip A/C and don’t mind deep cycles.
Of course you need to generate this amount of power using solar, genset or alternator (not shore power because you’re supposed to be able to operate away from shore). We manage with 1,875W of solar alone but you need to have the space to mount that. If you have 1kW then you need additional sources like a generator.

So to conclude: the Victron 3.6kW isolation transformer should be enough for cruising sailboats because it’s just for convenience when docked.

[Pete7]

Originally Posted by Sailorlou

Why do you draw 4500 Watts when cooking? Do you have an electric stove? It's rare to see an electric stove on a 40 foot sailboat.

True, but they are starting to appear, often a mix of gas and electric as the price of solar and LFP comes down. Also folk are becoming more accustomed to the idea of electric in place of gas, which is becoming a problem in the UK.

We have managed on electric cooking very well so far this year. Off again on Monday for 3 weeks holiday and whilst we may stop in a marina or traditional harbour we don't plan on using shore power. We have added an additional 180w flexible panel to the existing 600w plus 110w portable, for use at anchor or in a more traditional harbours. Results so far suggest we need 1.6kWh each day for cooking and the yacht.

However, we aren't running AC or a water maker, water being delivered for free in England Also appreciate it probably won't work during the depths of a UK winter at 50'N, which is fine. We do sail in the winter, but tend to use harbours which have cheap rates and because we want to stop there.

[YANDINA]

Originally Posted by boatpoker

1. Poster does not acknowledge working for that vendor.

2. OP claims it to be "failsafe" but it has no means of monitoring, as required by ABYC to meet the "failsafe" requirement.

2. Claims to Meet ABYC but is not tested by an independent lab. i.e. UL.

3. Website claims it blocks "electrolysis" but don't understand that in "electrolysis" the cathode is negative and the anode is positive (the exact opposite of galvanic corrosion current).

WHAT'S your problem?

1. I have never worked for that vendor. I have no relationship with that vendor other than I sold the business to them about 2 years ago. I get zero income from the sale or from their sales. I designed that isolator about 20 years ago and I'm proud of the design and not ashamed to promote it.

ABYC do NOT require monitoring if it is fail safe. With tens of thousands sold when I owned the company, all with UNCONDITIONAL warranty, we never had a single warranty claim. Not a single one failed, safe or otherwise.

2. It was originally sold under the West Marine brand name for about 12(?) years and I can assure you that it had full independent compliance testing by an independent lab before West Marine put their name on it.

3. I have no access or control over their website or what is said on it however the semantics of advertising text is not a significant factor for ABYC compliance.

[boatpoker]

Originally Posted by YANDINA

WHAT'S your problem?

1. I have never worked for that vendor. I have no relationship with that vendor other than I sold the business to them about 2 years ago. I get zero income from the sale or from their sales. I designed that isolator about 20 years ago and I'm proud of the design and not ashamed to promote it.

ABYC do NOT require monitoring if it is fail safe. With tens of thousands sold when I owned the company, all with UNCONDITIONAL warranty, we never had a single warranty claim. Not a single one failed, safe or otherwise.

2. It was originally sold under the West Marine brand name for about 12(?) years and I can assure you that it had full independent compliance testing by an independent lab before West Marine put their name on it.

3. I have no access or control over their website or what is said on it however the semantics of advertising text is not a significant factor for ABYC compliance.

1. ABYC 28.6 See Photo below. requiring a monitoring function.

2. There is no certification marked on the product nor identified in their literature nor yours when sold under the Yandina name (also an ABYC requirement). See ABYC 28.1.9.8 photo below

3. Whether a cathode (or anode) is positive or negative is certainly not "semantics". This is simple scientific fact. and shows a basic lack of understanding of the process. This statement about "electrolysis" was also on your old website.

[mvweebles]

Originally Posted by boatpoker

1. ABYC 28.6 See Photo below. requiring a monitoring function.



2. There is no certification marked on the product nor identified in their literature nor yours when sold under the Yandina name (also an ABYC requirement).



3. Whether a cathode (or anode) is positive or negative is certainly not "semantics". This is simple scientific fact. and shows a basic lack of understanding of the process. This statement about "electrolysis" was also on your old website.

At the risk of stepping into a cat fight, upthread, I cited a similar experience where Newmar, a respected name, made a vague claim about being engineered for all standards. An ABYC marine electrician on a different forum called me out on it in a similar manner as Boatpoker did here - the device needs to be independently tested for failsafe. So I called Newmar thinking it would just be a semantics issue. It wasn't. Newmar tech sheepishly admitted they were not compliant but we're working on it.

In my opinion, if you're going to install a galvanic isolator, spend the extra $50 for an ABYC compliant one. There is a bright line between compliance and non-compliance.

[s/v Jedi]

Originally Posted by boatpoker

1. ABYC 28.6 See Photo below. requiring a monitoring function.

2. There is no certification marked on the product nor identified in their literature nor yours when sold under the Yandina name (also an ABYC requirement). See ABYC 28.1.9.8 photo below

3. Whether a cathode (or anode) is positive or negative is certainly not "semantics". This is simple scientific fact. and shows a basic lack of understanding of the process. This statement about "electrolysis" was also on your old website.

Do you do that on purpose? Cropping out the part that says Yandina is right and the monitor is not required for fail-safe isolators?

That’s really not nice.

Attached the complete screenshot.

[boatpoker]

Originally Posted by s/v Jedi

Do you do that on purpose? Cropping out the part that says Yandina is right and the monitor is not required for fail-safe isolators?

That’s really not nice.

Attached the complete screenshot.

How do you know its fail safe ? She thinks these issues are "semantics". She also said she designed it 20 years ago before fail safe units existed ... can't find her patent. It has no independent lab certification. as required and shown in the other screen shot.

[boatpoker]

Here is the entire standard. People can see for themselves.

[s/v Jedi]

Originally Posted by boatpoker

How do you know its fail safe ? She thinks these issues are "semantics". She also said she designed it 20 years ago before fail safe units existed ... can't find her patent. It has no independent lab certification. as required and shown in the other screen shot.

You left out that the monitor is not required for a fail-safe unit AFTER she told you that the unit didn’t need a monitor because it is fail-safe.

[YANDINA]

I should not have to be defending my design but for some reason it is under attack.

No galvanic isolator is fail safe. The testing equipment we used can fail any brand of galvanic isolator to open circuit. They are only fail safe when connected in a circuit with the appropriate size circuit breaker.

Our isolators were not just type tested, every one we made was put through the full ABYC electrical test at 130% rated current until the temperature stabilized.

Despite your problem with semantics, I can assure you that my Galvanic Isolator design is very effective in blocking electrolysis.

My isolator was fail safe for years before it was an added requirement for ABYC. My isolator is the only one on the market with smarts that monitors the current and by-passes the diodes when overloaded. Perhaps you noticed that my design does not need aluminum heat sinks. Perhaps there is a reason why we never had a single warranty return.

So eat your grits and don't forget to feed the chickens. Females can be engineers - I graduated in EE before you were born.