1600 watt solar system

Skip3Skip3 Registered Users Posts: 13 ✭✭
My wife and I are on selling everything and becoming full-time rvers. I plan to install 8-200 watt high-tech panels in 2 strings for 800 watts each, use a connector box, 2-100 amp renogy charge controllers in parallel, into a 1000ah battery bank with a Aims 12 volt 120/240v split phase inverter. As this forum category suggests I am a newbie so I hope the following questions are not too stupid and that some will respond with the vast knowledge that I have found here.

The panels are Voc 24.355V, Isc 9.87A.  I would be connecting them in parallel so I am assuming each string will have 24V +/- and 39.5A +/-.  Will the 10 awg wire be sufficient connecting the panels together or should the wire gauge get larger as the amperage increases from panel to panel? 

Should I use a connector box to connect two strings to one cable, or connect each panel or pair of panels to a larger connector box?  Instead should I run 4 panels output separately to each controller?  I know that two 100 amp controllers are overkill but I may want to increase the system at some future date.

I also plan to connect the 2 phase inverter to each side of the 50 amp panel. I know that I will have to run the fridge on propane and flip the breaker off to the roof a/c. My wife cannot tolerate heat due to health   I hope to install a mine split a/c or a 5000 btu window unit both of which will pull around 450 watts.  

Does this make sense or I'm way off base?  Any comments or suggestions would be greatly appreciated. Well except those that might suggest that I really am hopeless.😀


  • SolfyrSolfyr Registered Users Posts: 22 ✭✭
    Volts add in series : 24  Vopencircuit x 4 ~ 96Voc per string .

    Those charge controllers are available in 100V and 150V , some in 250V .

    With 100 V CC you are limited to 2 panels in series and 4 strings in parallel .

    A 150 V CC there are fitting 3 panels in series and 3 strings in parallel , which would require 9 panels .

    You would need only one CC instead of two , with 4 parallel strings providing around 35-40 Amps .

    Battery Bank : 1000Ah * 12 V = 12'000 Wh or 12 kWh .

    1600 W of the solar panels will have difficulties to charge 6 kWh reliably , assuming Lead Acid batteries and
    a State of Charge at 50% .

    I would suggest 3 kW of solar panels to reliably charge the BBank at overcast days and below 50% SoC .

  • SolfyrSolfyr Registered Users Posts: 22 ✭✭
    edited October 2019 #3
    Renogy has a 100Amps Li CC , as found on their website .

    The specs are 150 Vdc max and 1300Wdc for 12 V, and up to 5200Wdc for 48 V .

    Here really one could consider strings of 4 panels in series for a 48V BBank ,
    5200 W / 200 = 26 panels max / 4 = 6 strings in parallel -> 24 panels + 60Amps .
    3000 W / 200 = 15 panels / 4 = 4 strings in parallel -> 16 panels + 40Amps .

    The battery bank would need to be remodeled to 250 Ah x 48 V .
  • SolfyrSolfyr Registered Users Posts: 22 ✭✭
    The amperage stays the same in series from panel to panel , or better finds the average of ( I1+...In )/n .

    In parallel the amperage adds l1+...In , so wires need to get thicker after the junction box ,
    where the strings connect to become parallel .

  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    The inverter (Aims 4kw 12vdc/240vac in, 120/240vac out?) spec has a 50w self consumption (on, but with no loads).  If on 24x7, that's ~1.2kwh/day, about enough to power an efficient full-sized AC fridge!  I'd consider using a larger inverter only for shorter duration large load circuits (eg microwave), and turn it off when not in use.  For long duration small load circuits (eg lights, laptop), I'd use a much smaller inverter (eg Morningstar 300w PSW) with lower self-consumption.

    It appears to have 240vac in.  Is that voltage shore power generally available where you intend to go?  Many mini-splits with good SEER ratings seem to be 240v, but there are 120v ones in smaller btu sizes.  Unless you really need 240v, I'd stick to 120v.

    With a 12000w 20sec surge rating, it could in theory draw > 1000adc from the 12v bank.  Even at the continuous 4000w rating, it could be >350adc.  That will require some really heavy wire and overcurrent protection.

    I didn't see a genset in the mix.  Given the PV mount space limitations typical in mobile applications, using a generator for the larger load(s) may make more sense than using a huge 12v inverter and trying to feed the beast with limited PV and DC storage.
    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
  • Skip3Skip3 Registered Users Posts: 13 ✭✭
    Thank you Solfry an Estragon for your comments.  I did not notice that the input was 12V DC\240 V a.c. Instead of 120. My bad.I will have a 5 KW genset in the mix as well. I know that the home's 50A panel is not true 240 but rather separate 120 on each leg.  I don't know what most 50A hook-ups will be. Would I not turn the inverter off when I connect to shore power with the RVs connecting power cord and only use the inverter when off grid?  I would get a 120V mini-split if I go that route.  It makes sense to have a smaller inverter for smaller loads while turning the 4000 off.  While I want to wire the 4000 to the main panel how would I wire the smaller one to the system as well?  
  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    When on shore power, you would typically leave the inverter on, as the larger ones generally include an AC transfer switch and charger.  When it sees acceptible AC voltage/frequency on the input (shore or genset power) it switches the line(s)/hot, and in mobile versions the neutral, from inverter to ACin and energizes the AC battery charger.

    I use a generator lockout sub-panel panel for circuits that can be powered by either my big (7kw stack) Outback inverters or small (300w) inverter.  The lockout ensures one inverter output can't backfeed the other by mechanically preventing both input breakers from being closed at the same time.  

    Large load circuits powered only by the big inverters or generator are in the main panel.

    Is the 5kw genset wired for 120 or 120/240?
    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
  • Skip3Skip3 Registered Users Posts: 13 ✭✭
    Truthfully I don't know. I am considering several mh that have the genset that was original. They are all 2005-2015 and I have not asked that question yet. They are all either 5500' 5000' or 7500.

  • Skip3Skip3 Registered Users Posts: 13 ✭✭
    Would most shoreline hook ups cause a problem with the 4000 inverter I mentioned?
  • Skip3Skip3 Registered Users Posts: 13 ✭✭
    edited October 2019 #10
    Thank you for all the help Estragon.  I do not plan on going 240  just 120 to each side of the main which I think this inverter will do thus allowing power to all 120 circuits.  I will switch the heavy load like microwave or water heater or a/c off when one or the other is on so there is not too much draw.  I think I misunderstood your question about 240 shore power.  I assumed that it would be like the house thereby supplying 50A with 2 110/120 legs?  The Aims inverter does have an automatic transfer switch so I figured that would handle the switch from shore.  I need to work out the generator and smaller inverter, and generator lock out panel.  Thanks for your knowledge. 

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