How much power from inverter? Confused by magnum diagrams

nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
So I’m not an electrician, but I’m fairly knowledgeable so I’m kinda embarrassed to even ask this because I AM new to DC and solar. 

Specifically I’ll refer to the magnum 2024, and 4024 inverters. Both inverters have diagrams showing a 30, or 60 amp input, and then have a table for single in single out wiring for 60 amps for all the ms inverters. 60 amps x 120 volts gives me 7200 watts which is more than the 2024 can handle (I think??) 

I don’t understand how much power I can draw from the inverter. Keep in mind I’m talking off grid power from batteries only. My pass through will be limited to my generator. 

I don’t know if I use the battery voltage, or ac voltage to calculate this. 

My interpretation is I can have 1 15 amp breaker/circuit with the 2024, and 2 15 amp breaker/circuits with the 4024. Obviously this is dependent on the battery bank. Let’s say 4 batteries, 6 volt @220 AH. 

So I guess what I’m asking is what is my service? I.e at home I have 200 amp service, to a 100 amp panel. Ms2024 gives me X amp service, and ms4024 gives me X amp service. 

Or am I thinking wrong about this. 

I wish magnum would give examples in the manual WITHOUT a grid connection. 

Hopefully I’ve communicated my question properly. 

Thanks. 

Comments

  • PhotowhitPhotowhit Solar Expert Posts: 5,974 ✭✭✭✭✭
    Not sure where you are seeing the different things in the manual,  You can hook up as many breakers/circuits as you like...
    The 'total service will be limited to the output of the inverter.  So roughly in amps 2000watts would be 2000/120=16.6 amps and 4000 watts would be 33 amps.

    I've lived with an 1800 watt inverter hooked to the 200amp (now)sub panel in my mobile home for several years.

    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.
  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Some of the diagrams show a 60 amp breaker feeding a 2000 watt inverter. That’s 7200 watts.  

    So basically a 2000 watt inverter would give me 15 amp service, and a 4000 watt inverter would give me 30 amp service. Either one breaker, or 2 breakers. 

    Wasn’t sure if the dc amps were calculated or not. 

    Thanks for the answer. 
  • mike95490mike95490 Solar Expert Posts: 9,583 ✭✭✭✭✭
    If you were to add up all the breakers in your household breaker, it would be far larger than the rating of the panel. its assumed you won't have EVERY load ON at the same time.
    Powerfab top of pole PV mount | 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 ,

  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Yes, I understand that. I was just trying to figure out how magnum expects me to pull 60 amps through a 2000 watt inverter. 

    I know the ac pass through when charging is different but strictly just pulling power from the batteries is different. 

    Obviously if I wire it for 60 amp service my main feed to the cabin will only be 15 amps. But I’d like to plan for future use, I.e run power to a boat house for running the odd tool. 

    I’m thinking maybe a 4000 watt inverter. 15 amps to the cabin, and 15 to the boathouse. 4000 watts should be enough for 2 15 amp circuits. 

    I think maybe I’m not explaining how I’m thinking of this properly. 

    My house has a 100 amp panel. Yes I’m not using everything,at the same time.  But a 2000,watt inverter even with not everything being used at the same time is not enough for 60 amps. Right?
  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    The breaker feeding the inverter is to supply the charger as well as pass through current, this could be either grid or generator, the conductors would need to be sized relitive to the breaker capacity, as that is the sole purpose of the breaker, to protect the conductors in the event of a short circuit condition. Ultimately the breaker capacity needs to be greater than the maximum peak load, so for the smaller inverter 30A would suffice as the peak demand would be less than the inverter rating.
    1500W, 6× Schutten 250W Poly panels , Schneider MPPT 60 150 CC, Schneider SW 2524 inverter, 400Ah LFP 24V nominal battery with Battery Bodyguard BMS 
    Second system 1890W  3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.  
    5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Got it. Breaker is also to prevent too much amperage flowing through wire. So 14 awg nmd cable gets a 15 amp breaker, 12 awg gets a 20. 

    As for wiring the ac to the cabin, a 2000 watt inverter gets one 15 amp circuit. If I want a 15 amp to the cabin, and a 15 amp. To the boathouse I should get a bigger inverter? 4000 watt? 
  • PhotowhitPhotowhit Solar Expert Posts: 5,974 ✭✭✭✭✭
    nan_wpg said:
    As for wiring the ac to the cabin, a 2000 watt inverter gets one 15 amp circuit. If I want a 15 amp to the cabin, and a 15 amp. To the boathouse I should get a bigger inverter? 4000 watt? 
    Only if you will be running loads totaling more than the 2000 watt inverter can handle.

    Like I said I had a 1800 watt inverter hooked to my 200amp service panel in my home, I also have an independent line run to my vinyl garage work area. I even managed to run my table saw off it, with nothing else running... I didn't run the air conditioner, microwave and table saw at the same time...


    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.
  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Ok, so I’ll run everything off a 2000 watt inverter. 15 amp breaker on the circuit. I just don’t run everything at the same time. 

    You’re running ac off battery power?
  • PhotowhitPhotowhit Solar Expert Posts: 5,974 ✭✭✭✭✭
    nan_wpg said:
    Ok, so I’ll run everything off a 2000 watt inverter. 15 amp breaker on the circuit. I just don’t run everything at the same time. 

    You’re running ac off battery power?
    Have been since I built a tiny house just for that in 2004. 10x16 with 6" thick walls. Built in the shade. Ran off 4 golf cart batteries to provide 8 hours of good sleeping temps. Solar panels were $4 a watt delivered back then, for cheapest available. Batteries survived 5 years, 4 years running the cabin. Shown with original 1000 watt array, later increased to 1600 watts.

    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.
  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Impressive! Nice setup you have there. 
    Any chance you have some close up photos of your panel mount? I’m looking for ideas how to ground mount my array. 
  • PhotowhitPhotowhit Solar Expert Posts: 5,974 ✭✭✭✭✭
    nan_wpg said:
    Any chance you have some close up photos of your panel mount? I’m looking for ideas how to ground mount my array. 
    Not of that mount, I sold the cabin 7 years ago, I do have some of my current setup.

    The old setup was all attached to a roughly 8x8 frame at the base, and the battery and power center sits on top to allow extra ballast. I do have more of the battery storage and power center. The 2 solar mounts are different with the left one designed to be raised with the season (in pairs). The right is fixed. I never used the feature to raise them for a better angle in the summer. PVWatts showed the advantage was minimal.

    My current setup is fixed with 4x4 for ground contact in cement below frost level. I did this at the suggestion of a engineer. If you pour concrete to the top it creates a fulcrum for the post to break. 



    The 4x4's come up and are sandwiched between 2x8's on either side top and bottom. Raising the top 2x8's wasn't the easiest...lol. The bottom framing really isn't required I had the idea of using a strong triangular shape to make it more ridged, I think this was pointed out to me here...

    I used decking boards for the panel support joists, I had intended to use 2x6 PT lumber, but both lumber yards had very ugly #2's, the decking was much more free of knots and had the strength the direction I needed. They are mounted to sections of 4x4s between the same 2x8s that are supporting the array at the corners. They have enough purchase with the 5 1/2 inches of contact to maintain a upright position. 

    I cut aluminum mounts and predrilled them so the spacing would be even, this is from the old cabin system. I used SS nuts and bolts, I bought nuts and bolts with different SS formulations, at someone's suggestion that it would prevent them from galling, not sure if it helped, I did have a problem a couple times. I found some larger 2x3" aluminum angle to make the mounts for the current system.

    I had to buy 4' longer supports under the panels, because the panels ran 6" too long. I asked my brother an engineer and some others about what they thought if I mounted some more panels and ended up adding 4 across the top.  It makes for a very tall array, I have tees behind so it's hard to get much pressure going the wrong direction. It's survived for 7 years, I usually inspect it about this time each year, haven't seen any issues, It's survived 1 1/2" hail, 60 mph winds and...

    ...16" of snow. I find I have a problem reaching the top 4 panels with my 20' long extension pole. I worry as the array/wood ages it might become a problem with heavy snows, but it's done quite well so far.

    The power center is under the array. Here it is with the small 1800 watt inverter. I added a 1100 watt inverter for yard work in the summer, so I could keep the air conditioner going, I now have a 4000 watt Magnum mounted above the 1800 watt inverter. I have yet to put the bypass switch back in the E-Panel so I could just flip a switch if I have a failure. I'll add a third Midnite Classic 150 to the right for the panels above the original 4000 watt array and 4 panels I setup originally to run a direct DC water heater. The forklift battery sits to the right of the power center if you follow the heavy cables. It's slightly undersized originally sized for the cabin system. It's 24 volt, 16 kWh. Original array was 4000 watts added 1000 watts across the top.

    Rewired a positive ground combiner box to run the 2 different arrays to the 2 different charge controllers. This would not be as complicated if I went with a 48 volt system. I would only need 1 charge controller.
    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.
  • nan_wpgnan_wpg Registered Users Posts: 7 ✭✭
    Awesome! Thanks for the pics. It gives me some ideas. What is a positive ground combiner? It looks different than,the standard grounded setup. 

    Your array angle looks about 45* or so? That’s the year round angle for my location. At our cabin the neighbors sit their arrays completely vertical for the winter. There’s lots of reflection from the snow. Having said that they do it because they aren’t around all winter and snow shedding is guaranteed with vertical panels. 

    My setup will be much smaller. 3-600 watts of  panels, bogart charge controller, 4 batteries, and a magnum inverter. Still trying to decide voltage, and  inverter size. 
  • PhotowhitPhotowhit Solar Expert Posts: 5,974 ✭✭✭✭✭
    My Latitude is 39 degrees in Central MO. It's about 45 degrees.

    The combiner use to be a positive ground it's a fused version of a standard combiner using fuse holders instead of a din rail and breakers. I used a couple power distribution blocks to combine the leads. It is a combiner for 2 arrays, going to 2 charge controllers. 

    When it was a positive combiner box, it had used the fuse holders, but had some connection to the heat disrupter on the left of the box (the only reason I mentioned it). Can't recall the exact connection means. I bought 2 for the NEMA boxes and fuse holders for $30 + $20 shipping $50 total. They originally used a 'ring post' to combine the leads, A cheaper but and less elegant solution. 

    I wouldn't go as tall unless you have woods or a building behind the array. Better to go a single portrait or 2 in horizontal stacked for a lower profile to the wind.
    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.
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