Converting to 230V setup

Discussion in 'OnBoard Electronics & Controls' started by skatun, Mar 16, 2020.

  1. skatun
    Joined: Sep 2010
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    skatun Junior Member

    Hi all,
    So we bought an old racing yacht 6 years ago and has been transforming it into a fast cruiser. Since we didn't have any propane on-board the choice of going for 230V were easy. So far we have installed induction cook top, water boiler, dish washer, baking oven, hvac, electric grill and floor heating. All of it running on 230V. Until now we have just used it when running on shore power, but now summer is coming and it would be nice to use while underway as well.

    Last year we installed:
    1. New 12v starter motor(SM)
    2. a 12V 55A alternator(ALT) .
    3. We have now got a hold of 2.2kwh(LiFe) of Nissan Leaf battery running 3S2P(24V)
    4. Inverter(INV,https://www.amazon.de/gp/product/B01M8LOSA3/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1) which can produse 2.4kW continous and 6kW peak. It has inbuilt charger for Lipo and has solar panle input.
    5. We have also built a targa and installed 500W peak power of solar panel(PV).

    Until now we have had one starter battery and(GEL) one battery bank(GEL), however we have now gotten two of these battery selector(BS,US $13.11 52% OFF|12V/24V Dual Battery Selector Switch 300A Battery Main Switch 4 Position Switch Selector for Car RV Boat|Car Switches & Relays| | - AliExpress https://www.aliexpress.com/item/33010385984.html?spm=a2g0s.9042311.0.0.27424c4dD5NMgq) . So thats what we have got so far, now the question is what else do we need?

    We assume we need :
    1. Seperating diode(TD): https://www.amazon.de/dp/B01BF5BYPS...=1-2&swrs=A195057A78F778C048928E93759A6F63&th
    2. 24V to 12V DC/DC converter?
    3. BMS: US $7.73 11% OFF|DYKB smart BMS 6S 7S 24V 60A 80A 100A li ion Lithium battery protection board balance Bluetooth phone APP UART software monitor|Battery Accessories| | - AliExpress https://www.aliexpress.com/item/4000431582969.html?spm=a2g0o.productlist.0.0.ab367546SBI4t0&algo_pvid=4ee8a6fb-a18d-4ad2-a68d-ab1923532c1c&algo_expid=4ee8a6fb-a18d-4ad2-a68d-ab1923532c1c-17&btsid=0ab6fab215843500999346317e449d&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
    4. 12V charger for Lipo 24V battery

    So the schematic which I have drawn below is that correct, or am I missing something?

    I am little bit worried about that the inverter is a single point of failure, the fuse will handle over current if the inverter fails to do this, but there is no under voltage protection of the battery except of the inverter, and there is no protection if the charger fails and overcharge the battery. Is this something to worry about?




    IMG_20200316_102426.jpg



    Hope the sketch is clear:)
     
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    It is missing the ground connection for the 230V from shore power and the inverter. Also Ground Fault protection. You may also consider an isolation transformer for electrolytic corrosion protection.
     
  3. Ike
    Joined: Apr 2006
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    Ike Senior Member

    Frankly, you should hire an electrical engineer with experience in marine systems. If you make a mistake here it's going to cost you your life or the boats.
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    There is an article in Professional Boatbuilder magazine with the proper circuit design for isolated and non-isolated systems. Read it online and copy the diagram.
     
  5. Ike
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    Ike Senior Member

    Which issue is that in?
     
  6. gonzo
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    gonzo Senior Member

    October/November 2019 by Steve D'Antonio, page 100
     
  7. Ike
    Joined: Apr 2006
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    Ike Senior Member

    Thanks I'll look it up. Must have missed that one.
     
  8. skatun
    Joined: Sep 2010
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    skatun Junior Member

    Thanks for the feedback, I just got a baby girl thats why the late reply. I have listened to comments and made the schemetic in visio as seen in the attached PDF. I hope it is clear now.
     

    Attached Files:

  9. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Is it correct that the shore power is only connected to the inverter/charger? Seems quite convoluted. With the amount of chargers and converters, you would be better off running a 220V generator at the engine.
     
  10. skatun
    Joined: Sep 2010
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    skatun Junior Member

    So the reason why we have chosen the electrical layout is as follows:


    Its easier, cheaper and more convenient to run things on 230V vs gas or 12V. With the high efficiency of the inverter and the higher voltage also the cable loss will be smaller than a similar 12V system. If the fridge breaks you can just go and get a new fridge straight away almost everywhere, the same might not be true for 12v or gas.


    This also means that we need to have quite a big inverter, so as soon as you pass 3kW all system will operate at higher voltages I think its just the fact of efficiency and cable size. Look at SV delos they also run 24V system and it seems that this is the new standard. However we have an old boat with 12V starter motor, alternator and instruments and lights so we need the 12V for those things.


    The Nissan Leaf batteries comes in a configuration that makes 24V suitable, and LiPo batteries seems to be way to go for storing energy. So we need a way to create that energy and the natural way is solar panels and wind generator. In addition you could say that you have a generator to charge the batteries and take peak loads, that might be true but we would like to avoid installing one right now. On the other hand we do have a 1.3kw generator in the yanmar 2gm20 motor. So with a battery bank of 2.2kwh we hope to be ok for our daily cruising need. In harbors 16A shore power is normally accessible. For heat we don’t need to use electric so its just for cooking, dishwasher,hvac and some hot water.


    When you are at harbor or anchorage you want it to be quiet and hence hopefully we then don’t need to run the generator(engine).


    The engine should always start, hence we want to have a separate starter battery, but this might fail and hence we have a backup battery in our 12V household battery which is just for the toilet, anchor winch and autopilot which all draws a considerable amount of amps. So a battery selector makes it easy to swap between those two. To charge those two 12v batteries we use the engines alternator, but as I understood we need to use a diode to charge the two batteries simultaneously if we want to avoid the manual battery selector. Who has never forgotten to swap the selector once in a while and ended up with a flat battery when u need it?


    The big 24V battery bank is normally charged with shorepower or solar panel, however it would be nice to be able to charge it with engine as well. Since this is LiPo battery we need to add a Battery management system(BMS) as well. So any tips where to get a 12v lipo charger would be awesome.


    The instrument and led lights should have regulated 12V and not floating battery voltage which is somewhere between 11-14V. So here its DC/DC converters in play. In the rare case of the alternator failure, we could use the inverter to charge the batteries, but this should only be to generate energy to start the motor. The instrument and light should then be run through a step down dc/dc converter instead to save the battery.
     
  11. gonzo
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    gonzo Senior Member

    I think that the possible replacement of a 12V fridge is not enough to justify the cost and complication.
     
  12. skatun
    Joined: Sep 2010
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    skatun Junior Member

    Well as said its more than just the fridge on 12V

    We have:
    1. Induction cook top
    2. Baking Oven
    3. Dishwasher
    4. Water heater
    5. Kettle
    6. HVAC
    7. Battery chargers
    8. Laptops
    9. TV
    10. Fridge
    11. Electric grill
    12. Dehumidifiers
    All running on 230V, seems like SailLife and SVdelos is running 230V as well.
     
  13. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Did you look at the circuit diagram in Professional Boatbuilder?
     

  14. skatun
    Joined: Sep 2010
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    Location: Aachen

    skatun Junior Member

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