Announcement

Collapse
No announcement yet.

Wishing a review of my setup and plan

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

  • Wishing a review of my setup and plan

    Hello! I have a 7 foot by 16 foot cargo trailer and have completely covered nearly every inch of the roof with 4 solar panels. (Canadian Solar CS3U-355P - each panel: pmax 355 Watt / vmp 39.4 volt / imp 9.02 amp / voc 46.8 volt / isc 9.59 amp).

    These 4 panels are wired parallel and I plan to use the Morningstar MPPT TS 60 going to 4 12 volt deep cycle batteries wired in a 24 volt configuration.(I have 4 batteries wired 2 parallel and 2 series equaling 24 volts (Universal Power Group 12v 100Ah Solar AGM SLA). I plan to use a diversion relay to be added later.

    Obviously the thing is on wheels but I'm in Illinois and the record low was -36 F in 1999. (who knows with this weather) The average high is about 60 F.

    The primary use of the system is to operate a rooftop a/c unit (Dometic Brisk, Compression locked (startup) Rotor Amps (Alternating current) 70 Amps / Normal compression operation 13 Amps, Fan 6 amps.

    I will only be using the a/c for about an hour or so a day around noon.

    Converting the 24 volts to 120 volts ac I figure I need a 24 v 3000 watt continuous and 6000 watt surge inverter. If this doesn't run the air conditioner, I suppose I could cut a hole for a lower watt window air conditioner but I hate to do that.

    Much obliged for any reviews.

  • #2
    3,000w cont inverter is going to pull 125A from the 24v batteries. If the sun is bright at that time, the solar can contribute maybe 1kw, but that's still an extreemly heavy load for the batteries. It will work for a month or 2, but as the batteries age, it's going to start shutting down.

    Is the AC unit a 120V or 240V system ? (19A @ 120V = 2280) Have you considered the Power Factor, which is going to be about 0.7 if I was to guess ?

    Have you considered a mini-split system with an inverter compressor (low starting surge) ?
    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


    • #3
      Hello Blue Skies and welcome to Solar Panel Talk

      I see two issues with your setup but there could maybe be more.

      The first is an MPPT type CC should allow you a higher input voltage from the panels so you might be able to get them wire like your batteries in a 2S2P arrangement. If you have more than 2 parallel strings of panels you will need to include a combiner box with over current protection for each "string".

      The second issue is the 70 starting amps for that A/C unit. Even a 6000w surge capacity of the inverter may not be enough to get it going. It will all depend on how efficient the A/C is. You may want to try it out first with the batteries and inverter to see if it will start and continue to run for a few minutes.

      Comment


      • #4
        Just got up after a double shift. The insulation is 3 inch rigid polyiso. It would cost a fortune brand new but mine is reclaimed from a farmer. Smelled like cows but I coated it with shellac meant to cover smoke damage. It is closed cell, does not absorb water and releases it's internal cell gas that puts out fires if you try to burn it (which of course i tried on a scrap - it really did extinguish itself.) It is even marked R22. If anyone is close to springfield, il i may be able to help them get some at very low costs.I plan to use spray foam and caulk to reduce thermal bridging around the 2x4' structure. (refer them to guy who reclaims this stuff - I think he's still on craigslist). It's durable too. You're not supposed to but you can walk on it. The ceiling is a bit more tricky. I started layering thinner polyiso from the cull cart at home depot but I am thinking I have enough of the good reclaimed stuff to do the job so that will be better. Below the trailer between the steel beams I plan to screw up 3 inch styrofoam that someone was going to use on a dock but never got around to it. less chance of fire down there (I can only hope) and R value not so critical. THANK YOU everyone. All input and discussion welcome.

        Comment


        • #5
          PS I put masking tape on the windows and used one of those laser heat measurement things at various points inside. I found some thick mylar material VIVOSUN 6 Mil Mylar Film Roll 4 FT X 10 FT

          and may try to rig that up on a pull down shade or something. Still thinking on that issue.

          Comment


          • #6
            Originally posted by Blues Skies View Post
            Just got up after a double shift. The insulation is 3 inch rigid polyiso. It would cost a fortune brand new but mine is reclaimed from a farmer. Smelled like cows but I coated it with shellac meant to cover smoke damage. It is closed cell, does not absorb water and releases it's internal cell gas that puts out fires if you try to burn it (which of course i tried on a scrap - it really did extinguish itself.) It is even marked R22. If anyone is close to springfield, il i may be able to help them get some at very low costs.I plan to use spray foam and caulk to reduce thermal bridging around the 2x4' structure. (refer them to guy who reclaims this stuff - I think he's still on craigslist). It's durable too. You're not supposed to but you can walk on it. The ceiling is a bit more tricky. I started layering thinner polyiso from the cull cart at home depot but I am thinking I have enough of the good reclaimed stuff to do the job so that will be better. Below the trailer between the steel beams I plan to screw up 3 inch styrofoam that someone was going to use on a dock but never got around to it. less chance of fire down there (I can only hope) and R value not so critical. THANK YOU everyone. All input and discussion welcome.
            Good deal.

            Sounds like you have it nailed. I have seen a number of folks fall for the outrageous claims of high R value in limited space. Glad to see that you didn't fall for that

            Comment


            • #7
              well, i have replaced most of the r3 value at the ceiling with the r22. the difference is obvious, especially if you open the door. if you have ever had an insulated coffee cup that you came back to two or three days longer and said to yourself, "dang, this is still hot" - that is the idea. in winter, you want a "bathtub" that retains the bottom heat. convection is a culpret to look out for, i believe. and i think i still have enough fire retardent r22 to do underneath. what am i going to do in there? i don't think i answered that. what do you do in your bedroom? i don't mean to be offensive. what are we going to do today? What do we do everyday, Pinky? I'll have to do more pics if anyone is interested. This is the best forum ever. Thanks from the bottom of my heart, really. Peace on.

              Comment


              • #8
                working hard on the unit. when i referred to the "bathtub", i'm afraid someone might think i'm talking about a hot tub or something. i learned about it studying standard house insulation. if someone else could expound, it could help a lot of people. otherwise, keep you heat from sinking via convection during winter by keeping your floors, house/rv/etc. from escaping.

                Comment

                Working...
                X