Recommended advanced AC power for EU boats

[Lasseman]

I'm not sure what your design “safety” meant, you did not specify it. I meant compared to a similar single 5kva Quattro design, they are both “safe” designs if implemented with knowledge and quality accessories.

Redundancy I agree to some extent, redundancy I see as the sum of probability and consequences. And two is better then one, ok. But all added breakers and connection points with its cabling is more complex.

I am looking into Quattro (with a Isolation transformer) “one unit” implementation not because its perfect but because it is better for me. My installation is a redoing pretty much whole boat electrical and for me one unit design is better because of less complexity in my view, not only the installation but also error searching.

I do like how you think little outside the box, and I appreciate you post your ideas and arguments. Maybe I will change my mind.

[s/v Jedi]

Originally Posted by Thumbs Up

But as you point out is required by code. Removing it (the output neutral/ protective earth connection) would create a floating distribution system (IT) as in Jedi's boat, hospital operating rooms, ship controls etc. An IT system on a boat has arguments for being safer but includes some caveats (mainly fault detection) that should be addressed.

No, it is not required by code. None of the places with floating neutral need exceptions for code compliance. The IT power distribution with ungrounded neutral is common. What you probably mean is that it isn’t recommended by ABYC. That’s fine, they give guidance for safe boats and that guidance is correct... but dated. They do update their recommendations but it is a very slow process. In case of rcd breakers it took them 20 years to catch up with the IEC. Once they catch up with the trend of boats eliminating propane, kerosine, alcohol based galley systems, replacing it with electric which requires much more substantial installations, they may include this as well.

The point of these posts is about safety, reliability and continuity, not about ABYC, NEC, IEC or any other institute giving guidance or code requirements. Laws of nature don’t care about political borders, they are valid at all times and at all places.

[s/v Jedi]

Originally Posted by Lasseman

I'm not sure what your design “safety” meant, you did not specify it. I meant compared to a similar single 5kva Quattro design, they are both “safe” designs if implemented with knowledge and quality accessories.

Redundancy I agree to some extent, redundancy I see as the sum of probability and consequences. And two is better then one, ok. But all added breakers and connection points with its cabling is more complex.

I am looking into Quattro (with a Isolation transformer) “one unit” implementation not because its perfect but because it is better for me. My installation is a redoing pretty much whole boat electrical and for me one unit design is better because of less complexity in my view, not only the installation but also error searching.

I do like how you think little outside the box, and I appreciate you post your ideas and arguments. Maybe I will change my mind.

About safety I mean exactly what I wrote: there is no safer system and using one instead of two parallel inverters does not make it safer.

I have a lot of professional knowledge and experience in this field so I am genuinely interested in what you find complex about two units in parallel. They are connected exactly like a single unit would be, with the breakers doing the exact same function. Unless additional cost is a factor, I really don’t see the reason for your choice.

[s/v Jedi]

Originally Posted by tanglewood

Paralleled Victron inverters may not be as redundant as you expect. They have to be configured as parallel devices, and once that is done, both expect the other to be present and operational. If either inverter fails, the survivor will not operate until it has been manually reconfigured as a stand along inverter. With the proper adapters, software, and computer you can get the survivor back on line, but the system doesn't "just keep running" when one fails. It all stops working until you "fix" it.

With at least one other inverter manufacturer, you can lose a slave and the other(s) will keep running uninterrupted. If you lose the master, a reconfigure is required, but it's done through the control panel, not through adapters and software. So you only have a possibility of a service interruption rather than a certainty.

What you write about requiring reprogramming is correct. Knowledge about how to do that is required for self reliance. In case this is not possible, then the bypass breaker allows continued operation on shore power or genset while help is hired to fix this. The configuration is easy, and I never encountered boats who couldn’t handle it (people who can’t typically don’t have inverters at all)

Edit: redundancy is achieved even by carrying a spare in a box, it doesn’t need to be automatic. There are pro’s and con’s to either way so I have no preference.

[alaskanviking]

Originally Posted by Jammer

I think you could simplify considerably. Ditch the input breakers on the inverters and just use a rotary off-shore-gen switch for each one, and get rid of bus 3 and the associated breaker.

Bus 3 would be used to bypass the inverter chargers

Using the input and output breakers allows him to isolate the inverter chargers separately. Then use one to charge and the second to invert. Actually pretty clever and adds some redundancy.

It's 230v so I think I'd prefer you to parallel the inverter chargers instead of two separate busses.

Bus 2 is the shore power only output, its only on when generator is on or shorepower is connected. Bus 2 isn't needed, or at least shouldn't connect via the selection switch. I really can't find a reason to add bus 2 to the selector switch4 Connect that output direct to the one or two items that actually would need it. You can use Euro style breakers inside the electrical panel cabinet to Dave space on the panel. That's maybe the water heater or AC but there is value of having both on the regular outlet. I really can't find a reason to add that to the selection switch

[alaskanviking]

Originally Posted by tanglewood

Paralleled Victron inverters may not be as redundant as you expect. They have to be configured as parallel devices, and once that is done, both expect the other to be present and operational. If either inverter fails, the survivor will not operate until it has been manually reconfigured as a stand along inverter. With the proper adapters, software, and computer you can get the survivor back on line, but the system doesn't "just keep running" when one fails. It all stops working until you "fix" it

Looking at the schematic S/V Jedi isn't exactly parraleling like you are thinking.

Each inverter charger is essentially running one section of the panel bus, with the ability to switch to the other inverter charger if there is a failure.

Parreleling as you describe is more inline with making a split phase system from two multiples, OR connecting the output leads in parallel to the same panel bus. Both would need programming.

S/V Jedi isn't nessesarily doing that, however in his setup it is possible to switch to the same bus by accident. Not sure what that will do to the equipment if that happens without programming, or if you can programm it so it can parrallel or individually.

[s/v Jedi]

Originally Posted by alaskanviking

Looking at the schematic S/V Jedi isn't exactly parraleling like you are thinking.

Each inverter charger is essentially running one section of the panel bus, with the ability to switch to the other inverter charger if there is a failure.

Parreleling as you describe is more inline with making a split phase system from two multiples, OR connecting the output leads in parallel to the same panel bus. Both would need programming.

S/V Jedi isn't nessesarily doing that, however in his setup it is possible to switch to the same bus by accident. Not sure what that will do to the equipment if that happens without programming, or if you can programm it so it can parrallel or individually.

As my diagram is drawn, it is for full parallel operation. There is a VE.Bus link between the units for synchronization which I didn’t draw. The text in the diagram explains how to modify for the different options. If independent operation is used, the busses must be reconfigured by removing the OUT2 jumpers (or opening breakers and taping them to prevent switching back on) followed by moving the OUT1 jumper from the second inverter from Bus1 to Bus2.

About the OUT2 ports: we need Bus2 for other functions so my thought was to use it for this as well. There will always be situations where it enables someone to create what they need

[David B]

Originally Posted by s/v Jedi

The shore power norm in the EU is 230V at either 16A or 32A.

I never saw a 32A outlet anywhere. Of course they will exist somewhere, but they are very rare.

I don't know where in Europe you have sailed, but certainly in the Med (where we have sailed anyway - Spain, France, Corsica, Sardinia, North Africa, Malta, Italy, Corfu, Slovenia, Croatia, Montenegro), it is the exception rather than the rule, that you only have 16A outlets on the pedestals. The majority have 32A as well, and in some cases, (the bigger berths) no 16A.

[s/v Jedi]

Originally Posted by David B

I don't know where in Europe you have sailed, but certainly in the Med (where we have sailed anyway - Spain, France, Corsica, Sardinia, North Africa, Malta, Italy, Corfu, Slovenia, Croatia, Montenegro), it is the exception rather than the rule, that you only have 16A outlets on the pedestals. The majority have 32A as well, and in some cases, (the bigger berths) no 16A.

I’ve not sailed in those places. That said, when they only have a 32A outlet, you can simply use an adapter to connect your 16A cord to that.

I am rethinking the case for high power use for live aboard in marina scenario where continuous use of A/C combined with electric galley leads to battery cycling if only a 3.6kW shore power is available.

The problem is that the bigger transformers don’t allow 1:2 doubling for 120V shore power. We currently have two shore power options which I tried to eliminate in these diagrams.

[David B]

Originally Posted by s/v Jedi

I’ve not sailed in those places. That said, when they only have a 32A outlet, you can simply use an adapter to connect your 16A cord to that.

I am rethinking the case for high power use for live aboard in marina scenario where continuous use of A/C combined with electric galley leads to battery cycling if only a 3.6kW shore power is available.

The problem is that the bigger transformers don’t allow 1:2 doubling for 120V shore power. We currently have two shore power options which I tried to eliminate in these diagrams.

Yes, I have 9 adaptor cables on board. Mostly something to 32A, then I can adapt from there to 16A. The issue of course is then overload protection, but the MCB's onboard look after my side of it anyway.

[s/v Jedi]

Originally Posted by David B

Yes, I have 9 adaptor cables on board. Mostly something to 32A, then I can adapt from there to 16A. The issue of course is then overload protection, but the MCB's onboard look after my side of it anyway.

Can you post some links to the 32A inlet and shore power plugs/cables? I’m having trouble finding these here in the Americas, even though 16A isn’t too hard to find.

I’ll probably adapt to your setup with the 32A inlet for EU boats even when only using a 3.6kW transformer... which allows them to use 120V 30A shore power.

For protection I think a 32A ELCI works. If only a 3.6kW transformer is used, you simply put a 16A breaker behind that to limit it’s output current. The whole path from shore outlet, cable, boat inlet, ELCI to transformer is 32A rated. Many EU boats find themselves with a 16A ELCI which is costly to upgrade to 32A.

If you have a link to a DIN rail style 32A ELCI breaker that would be great as well.

[more]

Originally Posted by s/v Jedi

This post requires some clarification:

It is valid for all power systems that have one phase and a neutral. It is not valid for US split phase, for which I will post a separate diagram later.

The shore power norm in the EU is 230V at either 16A or 32A. Victron has an isolation transformer for either option, but there are consequences to the choice:

- I never saw a 32A outlet anywhere. Of course they will exist somewhere, but they are very rare.

- The Victron 7kW isolation transformer is 230V in/out only. It does not allow you to change a jumper and connect to a US 120V outlet like the 3.6kW transformer does.

For above reasons I recommend to use a 3.6kW transformer with 16A inlet. But I also recommend to upgrade all inlet wiring incl. shore power cord to 6mm2 (10AWG) so that it can be adapted for use with a US 120V shore power outlet. This is why the input breaker is 32A even for a 16A inlet.

Do not worry about 3.6kW not being enough to run everything aboard: the inverter/chargers have Power Assist which can add 6kW for a total of more than 9kW of available power. The 3.6kW, added to solar power generated, must be enough for the average consumption so that the batteries get charged when power demand is lower.

An advanced AC power system like this used to be for the big boats. Today, with solar power, lithium batteries and electric galleys on the rise, it has become normal for boats from 12 meter (40') and up.

This diagram is not all that is needed. It assumes you have lots of power generation systems, mainly solar (recommend 1500W minimum to mostly eliminate genset use), aboard as well as at least a 10kWh 24V lithium battery. These numbers are based on my direct experience... which may change in the future as we only have such a system for 6 months.

The diagram has two 3kW inverters instead of smaller ones or one larger model. The total 6kW is required for the all-electric option and multiple units provide redundancy and price effectiveness.

There is an old fashioned manual transfer switch to change between shore power and generator. This switching is typically not done often, with the manual switch being much more reliable than an automatic transfer switch or a Quattro inverter/charger setup which have two inputs... at much higher price. The only reason to select a Quattro would be higher capacity.

There are three output busses. Two are familiar as they connect to OUT1 and OUT2 of the Multiplus units, where OUT2 only gets power when shore power or genset power is available.

This can be changed in case you want to operate the inverter/chargers independently instead of in parallel. in that case bus 1 becomes the output of the first unit and bus 2 the second unit. This setup has a powerful benefit: using the breakers around the inverter/chargers, one can be forced to only charge the battery while the other can be forced to inverter mode. This allows the use of 50Hz power aboard while connected to 60Hz shore power. If this is used often and/or full inverter power is needed, a third unit or just a battery charger can be added to the diagram.

Bus 3 is a bypass bus. This can be used like the OUT2 for power only from shore or genset but it's also useful in case of equipment problems.

The distribution breakers are double pole for additional safety as well as flexibility and future modifications.

I have examples of panels included. Note that single pole breaker panels can be modified to double pole and that panels with rotary switches are available as well. I don't have these panels yet but plan to have them custom fabricated by online services that do just that.

to necessary complicated.
simple bulletproof design

dedupe list

[s/v Jedi]

Originally Posted by more

to necessary complicated.
simple bulletproof design

dedupe list

Talk about complicated... I have a basic diagram that does away with the genset... but it still has an inverter/charger instead of just an outlet.

Also, your diagram connects to underwater metals and DC power which is a big NO for floating power systems.

[Thumbs Up]

Originally Posted by s/v Jedi

No, it is not required by code. None of the places with floating neutral need exceptions for code compliance. The IT power distribution with ungrounded neutral is common. What you probably mean is that it isn’t recommended by ABYC. That’s fine, they give guidance for safe boats and that guidance is correct... but dated. They do update their recommendations but it is a very slow process. In case of rcd breakers it took them 20 years to catch up with the IEC. Once they catch up with the trend of boats eliminating propane, kerosine, alcohol based galley systems, replacing it with electric which requires much more substantial installations, they may include this as well.

The point of these posts is about safety, reliability and continuity, not about ABYC, NEC, IEC or any other institute giving guidance or code requirements. Laws of nature don’t care about political borders, they are valid at all times and at all places.

You should not ignore the recommendations. All of the standards addressing floating neutral distribution (Ungrounded, floating, IT) require continuous ground fault monitoring. It can be in the form of simple ground fault lamps or more sophisticated insulation monitoring. You have not stated why you think these requirements are unnecessary. You keep skirting the question.
If you are going to promote IT power on a boat without ground fault monitoring I think that you at least owe an explanation as why you think it is unnecessary.

[s/v Jedi]

Originally Posted by Thumbs Up

You should not ignore the recommendations. All of the standards addressing floating neutral distribution (Ungrounded, floating, IT) require continuous ground fault monitoring. It can be in the form of simple ground fault lamps or more sophisticated insulation monitoring. You have not stated why you think these requirements are unnecessary. You keep skirting the question.
If you are going to promote IT power on a boat without ground fault monitoring I think that you at least owe an explanation as why you think it is unnecessary.

Show me the requirement for insulation monitoring for mobile installations.