Multiple Power Sources - How to I combine ?

Hi All - 

No not 100% sure I am articulating this issue correctly but I will do my best. Here is my scenario: 

Solar system going into the Travel Trailer, this consists of

• Four (4) PV panels on the roof in a series / parallel configuration
• Combiner / Shut off box 
• Midnite Solar Classic 150 Charge Controller + Shunt
• AIMS 2000 Watt PSW Inverter Charger ( Please no comments on this; I know I cheeped out )
• Four (4) Interstate 195Ah 12v AGM Cell Tower Batteries. 
• Of course all the necessary wiring etc...

Currently in the trailer is a circuit panel that is a main and five (5) circuits two (2) are DC and the rest are AC, under that I have the old converter charger that I am going to just disconnect. 

I also have a 4500 Watt Onan Generator, built in, that the trailer power cord plugs into to provide AC power, that same cord and be unplugged and plugged into shore/grid power if available, I also use this cord to plug into a small Honda 2000 quiet generator as the bigger one is quiet outside but really loud in the Travel Trailer. 

So what I am trying to figure out, is do I need some sort of transfer switch to sense where power is coming from ? 

How can I have the solar and inverter feed most of my AC need but then supplement with external AC ? 

I of course want it all, I'm sure that someone smarter than I will know or has dealt with this. 

I would be glad to try and help clarify if this doesn't make any sense. 

Thanks

Comments

  • EstragonEstragon Posts: 2,219Registered Users ✭✭✭✭
    An inverter/charger usually has an AC transfer switch built in. When it sees an AC input, it passes the AC current through to loads, and uses some to charge batteries. In this mode, it's supplying DC current to the batteries, and passing AC through (but not inverting from DC). The Classic may also be supplying DC to the batteries if there's sun, and depending on the interaction of voltage setting on the charger and the Classic. There's no problem with multiple DC sources charging the batteries, but it's normally most efficient to use generator power just for bulk charging if necessary, and let solar finish in absorb.

    When there is no AC input (and only then), the inverter reverses the DC/AC flow, and supplies AC power to loads. If and to the extent the classic has power from pv, it will help supply the DC current to power loads.

    I don't know about the Aims inverter in particular, but that's how inverter/chargers generally work.

    Some have multiple inputs, and can differentiate between shore power vs generator power, but the Aims likely doesn't. As as far as switching between AC, you are the transfer switch when you plug/unplug the various external AC sources. It likely only knows if it sees an AC input or not, so you'll want to manually manage things like only bulk charging with the generator, but getting to float on shore power.

    This also assumes things are properly wired, so you aren't, for example, backfeeding generator or shore power into the inverter AC output ;-)
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • mike95490mike95490 Posts: 7,611Solar Expert ✭✭✭✭
    Wow, so you run a mobile cell town in your RV.  Pretty spiffy.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • EstragonEstragon Posts: 2,219Registered Users ✭✭✭✭
    Maybe an ISMI catcher? Surely they run on DC though, so no inverter needed :blush:
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • tr0ytr0y Posts: 54Solar Expert ✭✭✭
    Hey Thanks all ... So I did some digging and here is what I found; the inverter will just pass through to the AC side when plugged in with its built in transfer switch. As for three input sources of AC I asked the trailer manufacturer for a wiring diagram, they would not give me one Thanks Thor Industries !  

    I went under the trailer and just found a junction box where all of the inputs were tied together into one wire. So my guess is when any AC input was going in it was back-feeding the others, again quality work Thor ! 

    So I am going to rewire the power cord into the inverter and the inverter to the AC main in the trailer and should be done. 

    Thanks 




  • littleharbor2littleharbor2 Posts: 877Solar Expert ✭✭✭✭
    If you haven't bought the charge controller yet you might consider a different brand. Not that I'm knocking Midnite Solar by any means. The reason I mention this is that The classics have three cooling fans in them and can be quite noisy during the day as the are cycling on and off. 

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • mike95490mike95490 Posts: 7,611Solar Expert ✭✭✭✭
    I have both Classic and Morningstar MPPT 60A, and the Morningstar is as solid as they come, and silent.
    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • tr0ytr0y Posts: 54Solar Expert ✭✭✭
    edited April 27 #8
    I did buy the CC already; I went Midnite because of the large capacity in my low voltage (12v) application. Between our host and talking to Morningstar they both actually suggested Midnite. 
  • littleharbor2littleharbor2 Posts: 877Solar Expert ✭✭✭✭
    Wow! Morningstar has always been a rock solid controller mfg. I'm really impressed they would actually recommend another brand. I'm also surprised they wouldn't bring up the fact that their product is silent in operation vs. the triple fanned Midnite controller.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 700 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • EstragonEstragon Posts: 2,219Registered Users ✭✭✭✭
    My 45a Morningstar PWMs are fanless, but not silent (they make a fairly loud high pitched buzz at times). Probably just the PWM though, and IIRC there may be a setting (which MS recommends not using) to reduce or eliminate it. Mine are in a crawlspace though, so it's not an issue for me.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • scrubjaysnestscrubjaysnest Posts: 173Solar Expert ✭✭✭
    @tr0y...surprised by Thor, I call tech support give them the vin on our MH and they e-mail diagrams right away. They do have one lady that answers sometimes and she can be a little snippy but I always get a good response on support.
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