Help with breakers

toryc19toryc19 Registered Users Posts: 2

Hi, I need help, I have had many electricians that have no idea how to help me with installing breakers for my system,  Its for a small cabin, I have a 5kw inverter charge controller all In one.  It states it will use 200amps between batteries and 60 amp between pv and inverter.  I have two 330 watt solar panels and two 200 amp batteries ( i know I need more but if I can just get lights on right now it would be great!)  I someone could give me a diagram on how to do this and what breakers, how many and disconnect, combiner boxes etc so my electrician can do this for me... thankyou!!

Comments

  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    Need to know the nominal voltage of the battery bank.

    5kw inverter and 660w of pv suggests to me there may be some design issues, as you likely already know.

    Not a lot of electricians know much about the DC side of things.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • icarusicarus Solar Expert Posts: 5,433 ✭✭✭✭
    5kw inverter with only 200 ah of batteries?  Ugh!  Brand names would be helpful, including voltage specs A 5kw inverter from 12 vdc would require a ~400 amp breaker/fuse. From 24 vdc ~200 amps.  The inverter loses are likely to be a bigger load on the battery than the lights you are trying to power!  

    Bottom line...off grid systems need to be balanced between loads, battery capacity and charging regimen.  Using such a large inverter is going to be problematic.  For 600 watts of PV, powering a few lights, consider charging out the hardware for a Morningstar sursine 300 inverter and a Midnight Kid charge controller.  We have run our entire house on such a set up for 15 years, using 450 ah of 12 volt batteries. (4 6 volt T105s).  

    Tony
  • toryc19toryc19 Registered Users Posts: 2
    ok, I have 2 renogy 200ah batteries totaling 400, I can get some more....of course I didn't know what I was doing when I ordered it...its a VOLTACON, i also have two more solar panels of the same 330 watts, if i have to get a different set up i will, just hoping i don't have to.  And i would like to power more than lights, like the whole cabin. here are the specs
  • mike95490mike95490 Solar Expert Posts: 9,363 ✭✭✭✭✭
    This may help.  or not. (my system, which has been added on to since drawn)

    Using pre-wired DC epanel from Midnight is a big help, saves "reinventing the wheel".
    Since this, it's been upgraded with a 2nd PV array 2Kw and Midnight Classic 200 charge controller, which also wired up through provisions (breaker knockouts) in the epanel. Genset is a flywheel crank, 3kw diesel.



    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 ,

  • littleharbor2littleharbor2 Solar Expert Posts: 1,628 ✭✭✭✭
    Estragon said:
    Not a lot of electricians know much about the DC side of things.
    Boy, ain't that the truth.

    2.1 Kw Suntech 175 mono, Classic 200, Trace SW 4024 ( 15 years old  but brand new out of sealed factory box Jan. 2015), Bogart Tri-metric, 540 ah @24 volt AGM battery bank. Plenty of Baja Sea of Cortez sunshine.

  • EstragonEstragon Registered Users Posts: 4,495 ✭✭✭✭✭
    5kw inverter is really pushing it on a 24v system.  Whether it's better to start over or make do adding to what you have comes down to what else you want to run in the cabin besides lights.  A spreadsheet listing each load, how much power it takes, and how long it's used daily would be helpful.

    5kw is ~200a, requiring ~3/0 or 4/0 (about thumb size) wire from the inverter to batteries and 200a DC rated breaker.  The spec shows a "DC disconnector" (breaker?) rated at 100a with 00 (2/0) connection.  Maybe the 5kw is a surge (eg 5 sec) rating, with 2.5 kw continuous rating?

    Wiring 2 x 12v batteries in series (using the same thick wire for interconnects) gives you 200ah at 24v or ~4800 watt-hours, of which you shouldn't use more than 50% in regular use.

    Charge controller output is listed as 80a.  It isn't clear if there's a separate connection to the batteries, or it shares the battery connection with the inverter via an internal buss.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
  • icarusicarus Solar Expert Posts: 5,433 ✭✭✭✭
    How about you give us an idea of your load(s) and we can see if any of this makes sense?  My guess is that this is a “ready, fire, aim” system that is likely to perform very poorly...sorry to say.  All off grid hardware choices stem from the loads.  

    Tony
Sign In or Register to comment.