Can I do this?

Old Guy
Old Guy Registered Users Posts: 51 ✭✭
I have my system running great now I think thanks to the members here......

I originally purchased 4 panels but 2 are working great.  
I would like to use the other two panels for something.  Are there any devices that can run directly from the panels with no controller?

I was thinking about a ceiling fan.  They come in 120v AC for homes and 12V DC models for boats and RV's and I would be good with it just running when the sun was shining.  

With a 120V AC fan, could I just connect a inverter to the panel and run 120 to the fan or would the fluctuating current not allow this?

Would this work with the DC fan without hurting anything?  I got this idea from a small solar vent fan I have in the garage.  Its just a small panel and fan but its been working great for years.  It seems to be a regular 12V motor.

OR if anyone is running something straight from the panels or a panel/inverter setup I would like to hear about it.




Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    If you can find a DC fan and drive it directly from the solar panels--That would be better. Note that DC brush motors do not last very long in continuous operation (brushes wear out in ~5,000 hours of operation or so).

    There is a "black box" that goes between a solar panel and a small AC inverter--As near as I can tell, the black box has a voltage comparator and a relay. When the solar array voltage drops below ~10.5 volts, it turns off the AC inverter DC input to reset the low battery cutoff, to allow the inverter to restart. (most AC inverters "latch" the low battery voltage error and require a person to restart).

    http://mwands.com/store/12-volt-suntaqe-pwb-inverter-controller

    And a youtube video:
    https://www.youtube.com/watch?v=kZ1BzbzdrGY

    I make no claims about how well this will work for your needs or MW&S.

    If it cheap enough for your needs--You don't have much to lose.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Old Guy
    Old Guy Registered Users Posts: 51 ✭✭
    Seems like a fan with a brushless DC motor would be perfect.  
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    You could add the 2 extra panels to your controller and use a small inverter to power the fan using excess power, what size are the panels, I forget.
    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.
  • Old Guy
    Old Guy Registered Users Posts: 51 ✭✭
    Renogy 100 watt
  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited January 2017 #6
    You can add the extra 2 panels to your system and use a small inverter, say around 300W  or less to power a ceiling fan whilst the sun is shining, it would be a simple  addition, no need to look for special products, around $150 could get a reasonable pure sine wave inverte, Samlex  are ok, check the host's store, don't get a modified sine wave, they will make the fan growl, not nice on a quiet day.
    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.
  • Old Guy
    Old Guy Registered Users Posts: 51 ✭✭
    Thanks again Mcgivor.... I'm still trying to learn about inverters and how they can make 120 volts from 12. Its witchcraft I say!!!  I just think thats awesome and I want to buy one and put some MONEY in it and see if it can multiply that as well.   :D
  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    edited January 2017 #8
    Think of the inverter like a cashier making change. Two tens becomes four fives, but it's still twenty bucks ( less a commission in the case of an inverter). ☺
    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