Fifth Wheel 12v system

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Comments

  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Fifth Wheel 12v system
    Normok wrote: »
    Ok so this is a very crude diagram of what Im thinking, its only the AC part of the wiring. Also I would like to know if it is necessary to shut off the right breaker while running the generator as there will be 2 sources of AC power at the panel when the generator is on. Damn I really dont understand AC power at all.

    OK: Two major problems with your current understanding of the possibilities:

    1. Relying on manually "interlocking" the two breakers when running a generator is a very bad idea, and could be very costly. You may not be the only one who has access to the breakers, or you might slip up someday.

    2. You have an incorrect idea of what the AC in and AC out of the Magnum do.
    You would connect the generator (or shore power cord) to AC IN and your load panel to AC OUT. If you need a different size breaker for the generator instead of relying on its internal breakers, you will not be able to use one which is in the same panel.
    When the generator is running, the Magnum will internally disconnect the inverter function and will feed the power from AC IN to AC out and will also use it for battery charging.
    When the generator is not running, the AC IN will be disconnected from everything and the inverter will feed to the AC OUT. No Battery charging will take place.

    As far as the distribution panel is concerned, the inverter output or the generator output will be coming in through the main breaker and all of the individual load breakers will work exactly the same way in either case. (Assuming that you do not have any 240 volt loads.)


    The MS-2012 will let you use a 120/240 volt generator to its full capacity (up to 7200 watts), while the MS-2000 will limit you to whatever power the generator produces for a single 120 volt output (and no more than 3600 watts.)
    SMA SB 3000, old BP panels.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    Only read your last post but you are on very shakey ground. Sooner or later you will have the right CB on with either the gen or shore power producing power. I'm assuming that the gen is portable and you don't have a ATS - automatic transfer switch for shore and gen.

    You should expect to Let the Smoke Out with the inverter AC out connected to the panel.

    Doesn't your Magnum have a ATS? ie AC out indended for a standalone circuit? ie The output is passed through from the AC in or the inverter itself. And doesn't the Magnum ATS switch both the hot and neutral and When Inverting Bond the Hot and Neutral? ie You'll be bonding the hot and neutral in the inverter all the way back to the shore cord - not a good idea.

    I'll read the rest of the thread later to make sure I really understand your plan. But for now - DON'T.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    Incidently my ME2012 uses a 30A 120V input from the panel. Besides the charger there are 2 20A output circuits and both have their ATS. There are no connections between the AC output circuits and the rest of the rig except for the common AC ground. Suggest you consider something similar.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Fifth Wheel 12v system
    CATraveler wrote: »
    And doesn't the Magnum ATS switch both the hot and neutral...?
    Your 2012 has a two-pole ATS and the second pole can be used for a variety of purposes. (See post # 30)
    The 2000 has only a single-pole ATS.
    SMA SB 3000, old BP panels.
  • NormokNormok Solar Expert Posts: 36
    Re: Fifth Wheel 12v system
    inetdog wrote: »
    OK: Two major problems with your current understanding of the possibilities:

    When the generator is running, the Magnum will internally disconnect the inverter function and will feed the power from AC IN to AC out and will also use it for battery charging.
    When the generator is not running, the AC IN will be disconnected from everything and the inverter will feed to the AC OUT. No Battery charging will take place.

    As far as the distribution panel is concerned, the inverter output or the generator output will be coming in through the main breaker and all of the individual load breakers will work exactly the same way in either case. (Assuming that you do not have any 240 volt loads.)


    So if the inverter automatically switches from inverter to charger upon detecting AC power in - there would be no need to switch the breakers then. Right?
  • CariboocootCariboocoot Banned Posts: 17,615 ✭✭
    Re: Fifth Wheel 12v system
    Normok wrote: »
    So if the inverter automatically switches from inverter to charger upon detecting AC power in - there would be no need to switch the breakers then. Right?

    Right. Standard wiring for an inverter-charger (built-in transfer switch) is:

    AC SOURCE ---> Inverter AC IN ---> AC LOADS

    AC present at Inverter AC IN = Inverter charges batteries, loads are 'passed through' to AC source.
    No AC present at Inverter AC IN = Inverter supplies power to loads from batteries.

    There would be appropriately sized circuit protection between the AC SOURCE and Inverter, and on each AC LOAD circuit.
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Fifth Wheel 12v system

    I am guessing your furnace uses propane, so what in that system is using 150 watts? Fans?
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system
    bmet wrote: »
    I am guessing your furnace uses propane, so what in that system is using 150 watts? Fans?
    The typical RV furnace uses 6-8A for the fan and he might have 2 furnaces. 20hr a day is a lot of propane and the typical RV has limited insulation with thin walls.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    OP,

    That's one very large solar/battery system for a RV. But then you're in weather and temperature extremes. Tilting the panels may not be wise due to storms and strong wind. Your MS2000 could draw 15A for charging so why not connect it to a 30A CB? That also would give you 30A output capability when using AC pass through.

    There have been several good suggestions that suggest non RV standards. So I was wondering if this is a permanent site or do you intend to tow the rig and use it in CGs?
  • NormokNormok Solar Expert Posts: 36
    Re: Fifth Wheel 12v system
    CATraveler wrote: »
    OP,

    That's one very large solar/battery system for a RV. But then you're in weather and temperature extremes. Tilting the panels may not be wise due to storms and strong wind. Your MS2000 could draw 15A for charging so why not connect it to a 30A CB? That also would give you 30A output capability when using AC pass through.

    There have been several good suggestions that suggest non RV standards. So I was wondering if this is a permanent site or do you intend to tow the rig and use it in CGs?

    Ya its a fairly large system but the trailer is 41' long with 4 slide outs. I wasnt planning on tilting the panels as I was planning to use these panels:
    http://www.globalsolar.com/products/flexible-modules/rv

    I'm really planning on moving it but I dont want to do anything that would prevent that.
    Thats a good idea changing the breaker on the ac in to the inverter it would allow for faster charges. Thanks
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    With 30A AC input and the 2 optional 20A output CBs connected to 2 circuits you would have a nice automated setup.

    I'm wondering if 100A charging is adequate for your proposed batteries? Seems small as that is what I have for 440AH. Also consider that the charger will first supply amps to any house loads with the remaining amps for the battery.

    Also while the Magnum is an excellent charger you should be aware of 2 design limitations:
    1. To charge at the maximum it must have 120V at it's input (it's AC input, not somewhere upstream). Less input means less DC amps. Some models publish graphs, some don't. I typically get 80A with 116V.
    2. The display DC amps is based on AC input. Mine will indicate 100A when in fact it's only supplying 80A, this is measured at the DC output and includes house loads.
    The above is based on my actual measurements and confirmed by Magnum as design tradeoffs.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    BTW Most RVers aren't aware of the Magnum design limitations and 80A is a respectable charge. But I thought that with your high power usage and large battery bank you'd want to factor in gen run time, etc.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: Fifth Wheel 12v system
    CATraveler wrote: »
    BTW Most RVers aren't aware of the Magnum design limitations and 80A is a respectable charge. But I thought that with your high power usage and large battery bank you'd want to factor in gen run time, etc.
    Id' suggest that it may not only be a voltage issue with them. They seem to be very temperature sensitive and will go into " Charger Cut Back Mode", that is about the % you are seeing. I'v tried a lot of things to vent them better and I could never stop them from doing it, even on a open floor they will still cut back.
  • inetdoginetdog Solar Expert Posts: 3,123 ✭✭✭✭
    Re: Fifth Wheel 12v system
    Normok wrote: »
    I think 6 2v 1050ah batteries wired parallel should be enough but not sure.

    Try "wired in series". :-)
    SMA SB 3000, old BP panels.
  • NormokNormok Solar Expert Posts: 36
    Re: Fifth Wheel 12v system
    inetdog wrote: »
    Try "wired in series". :-)

    Ya Coot already checked me #2. My amatuer status is becoming more apparent by the minute. I should just pay someone but I just wouldnt be happy not understanding how it all worked.
  • PhotowhitPhotowhit Solar Expert Posts: 5,011 ✭✭✭✭
    Re: Fifth Wheel 12v system
    Normok wrote: »
    ....but I just wouldnt be happy not understanding how it all worked.
    "One of us, one of us..."
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: Fifth Wheel 12v system
    CATraveler wrote: »
    The typical RV furnace uses 6-8A for the fan and he might have 2 furnaces. 20hr a day is a lot of propane and the typical RV has limited insulation with thin walls.

    My 31ft 5th wheel uses only propane for its furnace, and I've got shore power available. Sort of maddening to use space heater, I added a second 20 amp line for that purpose since the RV came with 30 amp connection. The last family guest used up 30lb cylinder in 4 days.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system
    Id' suggest that it may not only be a voltage issue with them. They seem to be very temperature sensitive and will go into " Charger Cut Back Mode", that is about the % you are seeing. I'v tried a lot of things to vent them better and I could never stop them from doing it, even on a open floor they will still cut back.
    I've observed a temperature sensitivity DC float voltage. It has varied from 13.1-13.9. However the max charge rate limitation that I saw during normal daytime temperatures led me to conclude that my unit was defective. I was headed towards Everett and called about parts/repair. No need they said it's working as designed and needs 120V at the input terminals for maximum DC charge. In fact one day I had 119V and the charge rate was about 95A. But CG voltage is typically less than 120V.
  • CATravelerCATraveler Solar Expert Posts: 98 ✭✭✭✭
    Re: Fifth Wheel 12v system

    BTW An 80A charge rate is certainly more than adequate in a CG. My gen typically runs 116V which gave me the 80A limit and I wanted more to reduce gen run time. Perhaps the gen voltage regulator can be adjusted...
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