Results

Patman3Patman3 Solar Expert Posts: 62 ✭✭✭✭
Using what I learned here so far ( Thanks posters!) I rewired my two Mitsubishi 110W panels from 14 Ga 35' to 10 Ga 25' wires each panel, parallel 12V.  I did the changeover work at Noon, why I don't know but I was able to take before and after readings. I didn't want to loose any energy so I was all set to hot swap at 12:30 PM.  My frackin panels were 161 degree F underside, using an IR thermometer, and the Al frame was 126 degrees (near Las Vegas, NV, 36, 114), Ambient 96.
14 Ga 9.6-9.8 Amps max
10 Ga 11.0-11.1 Amps max
I will get 16 more watts for years to come - Thanks again!!!
Edit note: 500 foot wire spool $110. .22/foot, 50' per panel, $11 per panel to wire. A small price to pay for more efficiency.

I wonder if I should try those amorphous 64 watt panels? They have a much lower Vmp, so I may still be better off with these.

Comments

  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Results

    i don't recommend that you mix other pvs especially the amorphous type unless it is fed to an another controller independent of the one operating the mitsubishis. i'm glad to hear the wire change helped that much.
  • Patman3Patman3 Solar Expert Posts: 62 ✭✭✭✭
    Re: Results

    I wonder which would be better for me in such heat (72C, derated 20% or more).

    http://www.uni-solar.com/uploadedFiles/US%20Series%20Sell%20Sheet%20AA5-3604-01p.pdf
    or what I have now http://www.discountpv.com/pdf/pv_mf110ec3.pdf
    I noticed a yellow dot on each of the plastic wire cover plates and asked the guy and he said as far as he knew they aren't factory seconds.  I would think a green dot would be better, at least it's not red.  I ordered two KC-130's from our host, maybe replace them, but if I try those 64 watters I would not mix them because of the Vmp difference.  They are more expensive plus take up more roof space 4 panels vs. 2 now.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Results

    in paralleling the mitsubishis and the kyoceras there is a .5v differential and you will lose the extra .5v presented by the kc130s. multiply that by the current from them and you get a loss of 3.695w per kc panel or 7.39w lost for 2. this is why i said stay with the same pvs unless you know what you are doing or deal with a loss. now when mixing them if you run the kcs into one controller and the mitsus into another controller then they will work at full potential. that means 2 sb2000 controllers unless you wish to upgrade to one that handles more overall power for the kcs and to expand on the number of kcs while leaving the mitsus on the sb2000. if you were to parallel them and accept the loss and then decide to go with the unisolar pvs to be paralleled too then you will lose even more power from the kcs(1.1vx7.39amp per kc pv) and the mitsus will also have a loss now.(.6vx6.43amps per mitsu pv)
    i'm modifying this to say also that if you are using 4 mitsubishi 110s into that sb2000 that you are negating much of your current potential. i could be wrong on that because you indicated about 11.1amps realized with the wire change. if you plan 2 mitsus with 2 kc130s that is over current as well for the sb2000. each mitsu pv has a current rating of 6.43amps x 4pvs(as indicated in your signature area) = 25.6amps. the 25amp rating on the sb2000 is the mppted output. all mppt controllers are rated on their output current so divide that by 1.25 for the input current. the input rating on the sb2000 would be 20amps and you are 5.6amps over that. you get 0 mppt benefit with 4 of the mitsus paralleled. we like to see everybody get the most from their pvs so please make some changes and it seems your primary needs are in the controllers you choose. have a seperate controller for each type of pv you employ and make sure the controllers can handle the power you are inputting to them. make very sure each controller has the remote battery temp sensor as well.
  • System2System2 Posts: 6,290 admin
    Re: Results

    i have 24 100watt 12/24v panels . they are well above the mx60 output of 1. i still have a 220v airconditioner so extra power would be great. anyone out thier se a reason why i can not run in series, to a breaker, for cut off purposes, then to the pos. and neg. bus of the dc inverter.
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