Install solar with existing converter

dieseldave
dieseldave Registered Users Posts: 2
Hello
I'm installing a solar system on my 23 ft motor home and I'm looking for a wiring diagram that would shut off the solar charging when I plug into shore power or fire up my Onan generator. Any help pointing me in the right direction would be most appreciated. Thank You,, Dave

Comments

  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    edited October 2018 #2
    You wouldn't typically shut off solar charging when on shore/generator power. Having multiple charging sources is generally not a problem.

    An AC inverter/charger with an internal transfer switch would recognize and qualify incoming AC shore or generator power, switch from inverting to charging mode, and go through its charging regimen according to its programming.

    With limited solar typical in mobile applications, it iftem makes sense to bulk charge (up to ~75-80% state of charge) in the morning with the generator, and let solar finish with mid-day sun.
    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
  • dieseldave
    dieseldave Registered Users Posts: 2
    Thanks for the reply and information.
    I am running an inverter separate from charger/ converter. I don't have an inverter/charger with an internal transfer switch. I'm looking for a schematic or wiring diagram where I can add some sort of transfer switch to the 120v circuit breaker box that will shut off the converter when I'm boon docking and charging the batteries off of the solar panels. I'm trying to avoid powering up the converter when I'm powering up the 120v panel from the inverter.. I can build a switch in to turn converter off and on but it's just one more switch to remember to throw.
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    A transfer switch, auto or manual could be used, it has two inputs which could be shore power and inverter power. One would be prime with the other backup, the outputs are commoned which could feed a distribution panel. This setup has one shortcoming with using an inverter as one source, that being it will not turn the inverter off when the other source takes command, be it prime or backup because it relies on AC to provide the signal. This would require the inverter to be switched off manually when not required as well as needing to be turned on prior to, or after transfer, depending if auto or manual. It is possible to make a manual transfer with two circuit breakers, linked with a bar one being upside-down but there is a risk of both being in an on state, but for the cost of a purpose made device such as this
    https://www.alibaba.com/product-detail/2016-New-220V-400V-AC-63A_60488793790.html?spm=a2700.7724857.normalList.49.40a46c5e0I27k8
    which is what I've used to transfer between two inverters by programming one to go to sleep overnight, to allow a small backup inverter which is on 24/7 to take over the low load hours. For less than $20 which is what I paid as part of a larger order it seemed good value, not worth making one. The example is for reference purposes, always ensure the certificates are accepted in your area of use. The wiring is very simple if this is something that will work for you.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    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
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Estragon said:
    The diagram is for an inverter with an AC input, selection being between grid or generator, the proposed application is, if I'm not mistaken, to select between shore and inverter.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.