Announcement

Collapse
No announcement yet.

need help sourcing correct components

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #61
    So, I invite you to research what putting 2 panels in series will do.
    a) only need 3 combiner circuits (otherwise you need 6 breakers and a large box for them) use 10A 100VDC rated breakers
    b) smaller PV cables
    c) You will still have 40A from controller to batteries. That requires 8ga cable, not 11. Using a 50A breaker or fuse is handy to protect the battery cable from a fried/shorted controller.
    https://lugsdirect.com/WireCurrentAm...ble-301-16.htm
    d) every battery wire needs to be 1/0 and same with the wires to the inverter. 2/0 would be even better - less loss, but harder to work with.
    e) you need a 130A 50VDC breaker on your + battery cable ( or the proper size breaker for the cable used ) Your inverter may specify cable size and breaker/fuse size needed.



    Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister

    Comment


    • #62
      Originally posted by Mcmullen7242 View Post
      So I picked up everything. 6 of the Sharp panels in photo. A 1500w pure sine wave 24v. 4 agm 12v 120ah batteries. And a Tristar 45a control charger. I just need some help gathering the right wires and cables.
      I used the Morningstar website and plugged in my panels and the controller I use and they told me to have the 6 panels in parallel. Is that correct?
      Umm...I'm assuming that means you selected the "Tristar 45" product (the PWM charger), not the "Tristar MPPT-45" (the MPPT charger)? The TS-45 is a lot cheaper, but it's not an MPPT. IF you got the TS-MPPT-45 unit, then we're good; @[B][B][COLOR=brown]Mike90250[/COLOR][/B][/B] suggested three parallel strings of two panels, which is what you'll probably need to go with. I was going to suggest two parallel strings of three panels in series until I checked the Morningstar calculator, and found that if I assumed a record low of -10F, the maximum voltage from the panels could *just* exceed the 150v limit of the MPPT.
      For the breaker, since you will have to allow for nearly 100vDC, you need a breaker rated at LEAST for that high. DC arcs are hard to break, so an AC-rated breaker will NOT work here. I'd suggest something like this, rated 250vDC: https://www.ebay.com/itm/Low-voltage...s/173953388877
      - Note that sizing the breaker's ampacity here is not terribly important, just make sure it's more than the maximum power you expect to get from the panels. 5.47A (short circuit per panel) * 3 (panels in parallel) = 16.41A (total maximum current)...you will PROBABLY be fine with a 16A breaker (as it will need way over 16A to trip), but a 32A would be better. Note that the panels' maximum power current and the short circuit current are SO close that a regular mechanical breaker cannot tell between the two. We're simply using the breaker as a disconnnect--it's hard to find switches rated for high DC voltage.
      - Note that DC breakers are POLARITY SENSITIVE. Notice the "+" and "-" on top of the breaker in the listing linked above? That's important.

      Also what size wires and connectors do I need to hook them up together and to get to the controller?
      Pretty much all solar panels these days use MC4 cables (until [USER="33699"]littleharbor[/USER] finds something else to surprise me with ). MC4 extensions can readily be found on eBay; I would suggest buying three (black) extensions of twice the length you need, and cut them in half. That way you can easily plug into the panels, and then wire the other ends to your solar panel breaker (above). Then you'll need some wire to go from the breaker to the MPPT charger; make sure it's rated for the 16A. (**Also, make SURE the polarity to the MPPT is correct BEFORE you turn it on. A multimeter can literally be a lifesaver...hopefully you have and know how to use one!)

      Here's a link to MC4 cables already pre-cut and prepared for wiring up; not sure if you're into serious price-shopping, but this will work. You will need three sets of these. https://www.ebay.com/itm/10-12-AWG-M...r/163028287258
      Whatever you get, just make sure it's MC4, and 12 or 10 AWG. Note that they make red/black pairs of MC4 cables--if you use my method (buy twice the length, cut them in half), you'll have some red wires on the negative line...and some black wires on the positive line, which will be terribly confusing.
      (They do make triple combiners, where you'd only need one main set of MC4 cables. HOWEVER, 16A is a little high for that, not to mention the losses in the line to your breaker.)

      also I looked up a chart for what cables I need from the battery to charger and it said to go with a gauge that can handle the max amp of the charger so that would be 11 gauge according to the chart.
      I'll agree with [USER="1076"]Mike90250[/USER] on that one, that you should go with 8AWG. At the very least, it reduces voltage drop.

      and then what would I need from the battery to the inverter?
      i looked up a battery chart on how to get my batteries wired up so I got that down but is there a certain gauge cables I need or just any battery cables?
      My 2 cents...you should be just fine with 2 AWG wire (rated 95A), as you only have a 1500W inverter. HOWEVER, if you are planning on upgrading to a bigger inverter/system down the road, just bite the bullet today, and get wire like [USER="1076"]Mike90250[/USER] suggested, 0 or 00 gauge; you'll save money in the long run. Don't use battery starter wire--that's dinky compared to what off-grid solar uses! I don't know what you'll need to mount to your batteries, but if they're bolt terminals, you'll need wires with ends on them. I personally used a blowtorch and soldered mine together, though you're probably better off buying cables with right ends already crimped on.

      AND...breakers, breakers! If you ever melt down a lead acid battery, or heat a wrench cherry red, or (like me) blow your meter up by accident, you'll appreciate a breaker! Breaker on the inverter. Breaker on the MPPT to the battery (like [USER="1076"]Mike90250[/USER] suggested). At 24v, you might be able to get by with cheaper breakers (most are rated at up to 30vDC), but I'd make sure any breaker I used on a solar system has an adequate DC rating.

      Comment


      • #63
        Thanks you for the help, I was also thinking to set the panels up that way but was confused why the website was saying otherwise. I got the MPPT version of the controller and the previous owner already installed breakers on it to connect to the panels and then going to battery. Also I plan on upgrading to 48v in the future so I'll go with the 0 or 00 gauge from the battery to inverter, thanks. Sorry for taking long to respond but I'll have power soon to be able to comment regularly haha

        Comment


        • #64
          I'm Assuming (since you are well above 300w) that you will be using a MPPT controller. Using 34V panels with a PWM controller with a 24v battery bank is not "bad" but you are working with some really heavy cabling for all the panels.

          Anyway, I'd laid out the links for the gear in my earlier posts
          Powerfab top of pole PV mount (2) | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
          || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
          || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

          solar: http://tinyurl.com/LMR-Solar
          gen: http://tinyurl.com/LMR-Lister

          Comment


          • #65
            Originally posted by Mcmullen7242 View Post
            Thanks you for the help, I was also thinking to set the panels up that way but was confused why the website was saying otherwise. I got the MPPT version of the controller and the previous owner already installed breakers on it to connect to the panels and then going to battery. Also I plan on upgrading to 48v in the future so I'll go with the 0 or 00 gauge from the battery to inverter, thanks. Sorry for taking long to respond but I'll have power soon to be able to comment regularly haha
            Just a comment: if you're planning on upgrading to 48v in the future, you won't need super-heavy wiring; 3KW @ 48v is all of 62.5A, well within the range of 2 AWG wires. However, if you were planning on staying at 24v and going 3KW, you'd be wise to use bigger wires.
            And, so you're aware, there's absolutely NOTHING wrong with using extra heavy wire (0 or 00)...it just hurts at the wallet level a bit more . Have fun, and be safe.

            EDIT: Good on the MPPT. The Morningstar website only suggested "6 in parallel" if you had the PWM version; with the MPPT version selected, it suggested 2 panels in series.

            Comment

            Working...
            X