my inverter has two positive and two negative

i bought a pure sine inverter for a o,55kw submisive pump. i want to connect but it has two positive and two negative on dc connection. rated 1500 w and peak power 3000 w. input 12dc output 220vac and 50hz frequency.


  • PhotowhitPhotowhit Solar Expert Posts: 5,656 ✭✭✭✭✭
    I've seen this before in inexpensive inverters, I suspect they are bonded/same input, but check your owners manual. With a 12 volt 1500 watt inverter, you will want very heavy wire from your battery bank, as too thin a wire will create a voltage drop and your inverter may shut down, 1500 watts at 12volts is (1500/12=) 125 amps! You will want your battery bank close to the inverter to shorten the wire runs as well. Also having too small a battery bank can create a problem as the battery capacity in amps is rated at a 20 hour discharge (normally) Higher discharge rates will effectively lower the available capacity.
    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, 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.
  • mcgivormcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    Have seen an inverter with 2 sets of DC inputs, a 2000W 24V in this case, at a local store, looked to be 2×1Kw units stacked, not sure if this is the case with yours, do you have a make/model or some pictures? Dose it have 2 cooling fans ? The Cotek SK 2024 is a stacked unit for sure but has only one set of DC inputs and 2 fans, 1 for each individual inverter.
    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.
  • BB.BB. Super Moderators, Administrators Posts: 32,014 admin
    Some of the higher wattage 12 volt AC inverters use parallel positive and negative cables (instead of one larger cable). For example, the maximum current would be:
    • 3,000 Watts * 1/0.85 ac inverter eff * 1/10.5 volts cutoff = 336 Amps maximum (~168 Amps at 1,500 watts continuous)
    Generally the manual will tell you the recommended wiring size (AWG in US, and maximum length).

    Download Brochure - Aberdare Cables

    This seems to give some good information on cable capacity for South Africa:

    Do you have a link to the inverter manual?


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
Sign In or Register to comment.