Scenario - im new to charge controller function

bsolarbsolar Posts: 103Solar Expert ✭✭✭
12v system stand alone system, its not grid tied - (2) 2500w inverters, (8)210ah golf cart batts wired to 12v, (12) panels that put out roughly 8amps each at peak sun.
...my question is - during peak sun hours i run the system, water pumps, fridge, fans, ect and pull alot on it .. can i expect (2) C60 chargers hooked into the bank and drawing from the same common output of the array to function to keep up with the load? will that work right or is my thinking flawed?

Comments

  • mcgivormcgivor Posts: 2,059Solar Expert ✭✭✭✭
    edited April 2017 #2
    Your thinking is flawed if you intend to share one array with two controllers, each controller should have its own separate array, you could  split the current array into two, the controller outputs can be commoned as long as the settings for both controllers  are the same. Sidebar, that's a lot of inverter for a 12V system.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • EstragonEstragon Posts: 2,615Registered Users ✭✭✭✭
    If the C60s are the ones I'm thinking of, they're PWM type. I think if they were MPPT, they would confuse each other as they sweep to find max power point.

    I'm guessing your 12v panels are wired in parallel for ~100a. If so, and the CC is PWM type, I don't see why it wouldn't work. It would need pretty heavy wire to handle 100a though.

    With that many panels (and batteries) in parallel you should have the parallel connections done with properly sized fuses or breakers.
    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
  • bsolarbsolar Posts: 103Solar Expert ✭✭✭
    ive got one yay and one nay .. sounds like the common outputs wont be a problem with the same settings ... i still have a question on whether or not i can draw from my current setup with both controllers - the c60 controllers 'are' pwm all the panels are wired and switched individually to a large pos and neg buss bar in a panel box i made up .. theres really no room in the box to create 4 buss bars i would have to get another box and redo alot of wiring to in essence create two arrays .. but if its necessary i will ultimately do it ...

    * on the inverters, plenty over overhead for sure, no bottleneck there lol .. theyre sunpro true sine inverters, i can put one on each leg of my panel box if necessary, backfed through a pump 240 line in the garage, thats the layout ...
  • PhotowhitPhotowhit Posts: 4,662Solar Expert ✭✭✭✭
    Connect each charge controller to it's own set of panels/Array. Connecting them to the same battery bank will be fine.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • westbranchwestbranch Posts: 5,084Solar Expert ✭✭✭✭
    I'm with Photowhit, 2 controllers 2 arrays, one battery bank
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge, Hughes1100 Sat Modem
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • bsolarbsolar Posts: 103Solar Expert ✭✭✭
    alright, thankyou guys .. i'm going to get into my array bus box and see if theres a way i can modify it so i dont have to build another box and wire it - cut the bus bars in half, drill them for another lug attachment ect ..
  • PhotowhitPhotowhit Posts: 4,662Solar Expert ✭✭✭✭
    Some are designed to work with 2 circuits, it might help to see one;


    Image result for MNPV8-MC4
    If you just want to add a 5-6 string box, there is alternative on eBay right now.

    If you are doing fuses;
    http://www.ebay.com/itm/Hoffman-Steel-6-String-Solar-Combiner-Box-SCB884M6S-/281950201745?hash=item41a58aa791:g:OAsAAOSwPc9W1P~X

    And if you already have breakers, I think the jumper comb would work for them.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • EstragonEstragon Posts: 2,615Registered Users ✭✭✭✭
    Photowhit and Westbranch - why do PWM controllers need their own array? Just trying to understand.
    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
  • PhotowhitPhotowhit Posts: 4,662Solar Expert ✭✭✭✭
    If you could get a manufacturer to sign off on it I would be fine, but 2 operating near capacity, I would wonder about one switching to float, and what the other would do with the added available input. Also these are switching on and off rapidly to limit voltage, so you have the available current fluctuating.

    Bill might have a better idea of it's feasibility.  I can certainly be wrong!
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, ForkLift battery. Off grid for @13 of last 14 years. 1000 watts being added to current CC, @2700 watts to be added with an additional CC.
  • BB.BB. Posts: 27,689Super Moderators admin
    MPPT controllers need their own array because they "sweep" the current and measure the voltage of the array--To figure out the Vmp and Imp operating points. If there are two or more MPPT controllers on the array, they will confuse each other.

    With PWM controllers, you can have one array going to two (or more) MPPT charge controllers (assuming they share the same ground/negative battery bus connections) charging two different battery banks (for example, on an RV, charging both the house battery and vehicle battery).

    However--The array must not be larger than the rated capacity of the smallest PWM controller attached to the array. If you have a 20 amp charge controller, the array cannot be larger than 20 amps. PWM controllers do not have the ability to limit the operating current through them. If you had a 40 Amp array and 20 Amp PWM controller--There would be 40 amps flowing through the PWM charge controller and it will attempt to pass all the available array current through the charge controller to the battery bank--Either shutting down (over current or over temperature) or fail.

    MPPT charge controllers have the ability to safely/reliably limit their output current via the MPPT circuitry (switching power supplies have current throttling capabilities because that is how the, typically, buck type switching supply works).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • mcgivormcgivor Posts: 2,059Solar Expert ✭✭✭✭
    edited April 2017 #12
    Thanks @BB. You took the words of the tip of my tongue, been thinking about this for a while, so in essence one could parallel two PWM controllers to a single array, but the array must be limited to the smallest controllers maximum current capacity, therefore there is no advantage in doing so, other than to reduce the demand on the electronic components of said controllers. So, if for example, the array has the potential to supply 60A, it would be advantageous to split the array into two 30A circuits using two controllers rated at 30A, or use a single 60A controller, no free lunch, but  brain food, none the less, thanks again. 
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • BB.BB. Posts: 27,689Super Moderators admin
    You got it McGivor.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • EstragonEstragon Posts: 2,615Registered Users ✭✭✭✭
    The Schneider C60 apparently has overcurrent protection, so in theory I guess @bsolar could get away with the one array.

    That said, rather than rely on the controller to protect itself with ~100+Adc coming at it, seems to makes sense to split the array.

    To split my 48v array, IIRC I just had to cut the +bussbar in the combiner and wire a controller to each piece. No extra boxes or bussbars. Would that not work?
    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
  • bsolarbsolar Posts: 103Solar Expert ✭✭✭
    Estragon said:
    The Schneider C60 apparently has overcurrent protection, so in theory I guess @bsolar could get away with the one array.

    That said, rather than rely on the controller to protect itself with ~100+Adc coming at it, seems to makes sense to split the array.

    To split my 48v array, IIRC I just had to cut the +bussbar in the combiner and wire a controller to each piece. No extra boxes or bussbars. Would that not work?

    theres just no room in my box and it was wired 'in place' as it were .. theres 24 stiff 12 gauge wires running into the box , then into 12 switches on the Pos side then on to the bus bars ... disassembling, cutting and trying to rig it would be a nightmare, but the box does have some room - i went ahead and bought 2 more bus bars and it 'should' ( hopefully) have enough play in the wires i can rewire everything without disassembling ... im committed to the operation at this point and bought the second controller .. its do or die heheh .. thanks again for brainstorming with me though ..
  • BB.BB. Posts: 27,689Super Moderators admin
    I believe the C60 will simply shut down. It will not "throttle" the current on a reliable/useable manner.

    - Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • littleharbor2littleharbor2 Posts: 979Solar Expert ✭✭✭✭
    Sounds like its time to upgrade to 24 volt.

    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.

  • bsolarbsolar Posts: 103Solar Expert ✭✭✭
    Sounds like its time to upgrade to 24 volt.
    and what would i gain from that with 900$ worth of 12v sine inverters ..... nah - ultimately 4 arrays of six panels, 4 C60's, and a 'detonate' button lol ...
  • jonrjonr Posts: 1,032Solar Expert ✭✭✭✭
    edited May 2017 #19
    The C60 will work with up to 85A of array but will shut down above that.

    Here is a PWM controller that isn't limited in array amps.  I'm not surprised, given that designing current limiting mosfet circuits isn't hard.

    "Charger will safely reduce output if panel current exceeds 31 amps."
    http://www.bogartengineering.com/products/solar-charger/

Sign In or Register to comment.