Final Approach

Chris11
Chris11 Registered Users Posts: 130 ✭✭
This spring I'll be putting it all in and running on it.



10 Grape Solar (Costco) 100 Watt panels. Outback80 controller. 4 (for now) Interstate 6 vollt 208 amp hour deep cycle bats. Straight from China 2500/5000 24 volt to 110 pure sine wave inverter.

I can't see buying a combiner...unless there's a reason I should use one. One of my questions to you.

This setup it to provide mainly lights, 110 volt well pump and whatever else I need for a small western theme town I'm building. So far 3 buildings but plan on putting up the 4th this year. Why I'm so vague about the needed wattage is I don't know the final needs as I add buildings. Hopefully I've overbought so it'll give me some latitude.

What am I missing? (Forgot, I have to get a bat temp sensor yet.)

Please keep it simple...I'm getting old and the gray matter ain't what it used to be...plus the beer don't help...lol.

Thanks, Chris




Comments

  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Chris11 wrote: »
    I can't see buying a combiner...unless there's a reason I should use one

    So how do you plan to connect the panels 2x5 arrays? You may not need a combiner but you still need to have a disconnect between however you will connect the panels (a combiner) and the Charge Controller for safety reasons. Otherwise you will have to undo a connection to work on any part of the system.
     
    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,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    westbranch wrote: »

    So how do you plan to connect the panels 2x5 arrays? You may not need a combiner but you still need to have a disconnect between however you will connect the panels (a combiner) and the Charge Controller for safety reasons. Otherwise you will have to undo a connection to work on any part of the system.


    Thanks. I never thought of a disconnect. I know when I used to drag race we had a disconnect between the bat in the trunk and the rest of the car...it wa mounted on the rear bumper. Cheap too. Please keep these type of helpuful hints coming....that's what I need and appreciate.
  • Photowhit
    Photowhit Solar Expert Posts: 6,002 ✭✭✭✭✭
    Yeah 2 strings of 5 panels if they are 12 volt nominal panels should work, Though I think Grape panels have a pretty high VMP 18.9v? so the VOC might be pushing the limits.

    1000 watts of array with a 208 amp hour 24 volt battery bank is pretty good size, but not huge, should give you about a Kwh of load to 25% discharge with an inefficient inverter.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    The VOC is 21.9 for each panel. The Vmmp is 18 v.

    Do you guys think a combiner is worth the money? To me, but I may be missing something, it's just simplifies the connections and has a disconnect. Is that correct?

    Fuses are also on my mind. Each panel has it''s own in-line fuse, then to a disconnect (thanks westbranch) onto the controller. The controller must have some internal fuses....I can't find anything anywhere on it. Then onto the bat bank. The bank has one fuse on the positive pole, I assume that single fuse will protect both in and out cables. Then onto the inverter which came with 6 - 20 amp fuses but I can't see where they go. One end has larger screw on connectors for the heavy cables and the other has 2 simple 120 volt recepticles. I don't yet know how or if I'm going to use a breaker box on one cabin then onto the others.

    Thanks for your thoughts.

    Chris
  • Vic
    Vic Solar Expert Posts: 3,208 ✭✭✭✭
    Hi Chris,

    If your system runs only two strings of PVs -- ie, two strings of five PVs, then a Combiner is not a must. But it is nice to have a Combiner even for only two strings, as it is handy when bringing up the system initially, and for debugging at any time.

    Have not seen an MPPT CC that has internal fuses, really doubt that the OB FM80 CC has fuses. It is the responsibility of the system designer to place circuit breakers/fuses where needed for safety. These protective devices are there to protect the cables that connect various parts of the system, not for protection of things like CCs or Inverters.. You WILL need a circuit breaker between the output of the FM80 and the battery. This will give you a convenient way of switching off the CC, and protect the cables that connect the CC to the battery. You will need to carefully consider the cable size and required breaker size before buying these parts of the system.

    A real Combiner for battery-based systems usually has circuit breakers that are DC-rated. These protect the PVs and cabling from excessive currents, generally, when there are three or more strings of PVs.

    And, before you buy that inverter, you might want to ask here, if anyone has direct hands-on experience with that specific model. Many here would counsel against buying an AIMS inverter. These have a very poor reputation. Many of the Chinese inverters consume high idle current (when supplying no power to loads), and have very sketchy specs., and are often unreliable.

    And, if your system will be inspected, you should carefully design it to pass inspections. Anytime that the safety of the public, or visitors could be affected by what you are doing, and how it is done, please consider having inspections, as a level of protection from liability exposures ...

    My opinions, Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    No fuses in my FM60, the smaller version of the FM80.

    The 21.9 Voc may be cutting things too fine depending on how cold your winters get. OB has a string size calculator tool that allows entering all the parameters and seeing if there are potential issues. http://outbackpower.com/outback-supp...ng-sizing-tool
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • ramloui
    ramloui Solar Expert Posts: 109 ✭✭
    Hi Chris11,
    I'm not as experienced as many of the guys on this forum but, thanks to them, I'm not as dumb as I used to be...:p
    What I've learned here is that there is some efficiency loss in the charge controller if the total voltage of a string of PV is too far away from the nominal voltage of the battery bank (ie 40 Vmp string into a 24 V nominal bank is more efficient than 60Vmp).

    Also, and now I'm looking for confirmation by others, if 1 panel or part of 1 in a string is shaded, wouldn't you loose most of that string's output?

    Overall efficiency may not be a sufficient reason to go with more strings, but, if true, potential shading may be.

    Enjoy your build!!!
    Off-grid cabin in northern Quebec: 6 x 250 W Conergy panels, FM80, 4 x 6V CR430 in series (24V nominal), Magnum MS4024-PAE
  • Mountain Don
    Mountain Don Solar Expert Posts: 494 ✭✭✭
    What ramloui said about shading and series strings is true. If the panel array has to be far from the CC series makes a lot od sense. We used series panels because of the distance being 325 feet. Plus our panels have no shading at all during the productive hours.
    Northern NM, 624 watts PV, The Kid CC, GC-2 batteries @ 24 VDC, Outback VFX3524M
  • BB.
    BB. Super Moderators, Administrators Posts: 33,433 admin
    Shading also depends on the controller MPPT software and possibly even he sequence of events could matter.

    A shaded string has (at least) two max power peaks. One of the two peaks is a true maximum.

    If the controller can find a local peak or a true peak, and track/find a new true peak as conditions change is not at all obvious.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Alaska Man
    Alaska Man Solar Expert Posts: 252 ✭✭
    Photowhit wrote: »
    Yeah 2 strings of 5 panels if they are 12 volt nominal panels should work, Though I think Grape panels have a pretty high VMP 18.9v? so the VOC might be pushing the limits.

    1000 watts of array with a 208 amp hour 24 volt battery bank is pretty good size, but not huge, should give you about a Kwh of load to 25% discharge with an inefficient inverter.

    and another disconnect between the battery bank and the inverter.
  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon. .

  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon. .

  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon. .

  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon.

  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon.
  • Chris11
    Chris11 Registered Users Posts: 130 ✭✭
    Sorry for not being around....I do appreciate how you guys have helped but today I spent time with a surgeon...trying to decide what to do with me. Nothing life threatening but I may be out of action for 6 months. Not a good time since I had planned, with your help, to get the solar system up and running this coming summer.. I don't know yet what's going to happen but at my age I don't like to lose a full summer. Dunno how many I have left...lol. Solar isn't my prime concern any longer.

    Again, thanks, and once I have more medical information I can make an informed decision regarding what I'm going to do. Hopefully I'll be back bugging you guys soon.