How do you connect 30A MC4 Y connectors to 50A MC4?

hmong2017hmong2017 Posts: 4Registered Users
edited March 9 in Solar Beginners Corner #1
TWO QUESTIONS. 
I am building my own solar system. 
Here is my solar information:
24V, 260 Watt per Panel. I have 6 Panels. Each solar panel rates 8.37AMP. 
I am at 50.22 AMP running down the line to the 80A charge controller if I parallel them. 

The problem I am stuck on was, I can't seem to find any 50A MC4 adapters to attach on my 2 Gauge wire. 
My 2 gauge wire is 50 ft long, from my Charge Controller to my solar panels. 

I plan on using the standard 30A MC4 2 to 1 Y adapter to connect 2 panels,  I then connect all of the 2 to 1 Y adapters ( total of 3 Pos and 3 neg) into the 3 to 1 MC4 Y connector 50A pos and neg.  

Now I am stuck, I don't have &  can't find a 50A adapter to crimp my 2 gauge wire on it to connect to my panels. 
I hope I made sense and that you understand. 
I am starting to assume that I will have to use a 30A to crimp my 2 gauge huge wire and use a 30a mce to connect to a 50a MC4? 

Also, Can standard 30a MC4 clip on with 50a MC4s?  or is the 50a MC4 is a lot bigger? Never seen one before. 
If these two question is solved then I am ready to order my stuff in. 

Comments

  • littleharbor2littleharbor2 Posts: 915Solar Expert ✭✭✭✭
    You need to terminate your strings in a Fused Combiner box.  Anything more than 2 parallel strings require individual circuit protection.   From there you don't need MC-4 connectors and can run from combiner to controller or breaker box in conduit.

    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.

  • mcgivormcgivor Posts: 1,769Registered Users ✭✭✭✭
    You'll need something like this https://www.solar-electric.com/mnpv3.html to combine the panels, maximum  two panels in parallel, any more than that, there is the possibility of a failed panel being back fed by a potential greater than a single panel. Having a single breaker per panel is useful in trouble shooting, combiner are available with more breakers than the linked example.
      1500W, 6× Schutten 250W Poly panels , Schneider 150 60 CC, Schneider SW 2524 inverter, 8×T105 GC 24V nominal 

  • Raj174Raj174 Posts: 589Solar Expert ✭✭✭✭
    @hmong2017
    What is the VMP voltage of the 260 watt panels. If it's around 31 volts, it's a 60 cell panel and not a true 24 volt nominal panel. Which means this panel wired in parallel will not have sufficient voltage to charge a 24 volt battery and the panels will need to be wired 2 in series by 3 in parallel. If the VMP voltage is about 36 volts then it should work ok.

    Rick 
    12 x 300W Renogy PV, MNE175DR-TR epanel modified, MN Classic 150, Outback Radian GS4048A, Mate3, 54.4V 207AH HI Power LiFePO4 no BMS, 4000W gen.
  • PhotowhitPhotowhit Posts: 4,544Solar Expert ✭✭✭✭
    To continue with @Raj174 thoughts on the voltage of panels and your overall system. What 80 amp charge controller are you using? Most that handle 80 amps are MPPT type. 

    MPPT type are good for this type of problem because they allow you to connect the panels in series, perhaps 2 strings of 3 panels to avoid needing fusing, as @mcgivor has said. When you add panels in strings, the voltage adds and the amperage stays the same. This is desirable for traveling longer distances with less loss of power(wattage) due to voltage drop in wires.
    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.
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