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Thread: Combining differing Series Arrays

  1. #1
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    Default Combining differing Series Arrays

    I have 4 Mitsubishi 120W panels 17.6V Vmp, 22.0V Voc, 6.84A Imp, 7.36A Isc ...

    I located some Luxen 130W panels 17.6V Vmp, 21.6V Voc, 7.39A Imp, 8.69A Isc

    I plan on 4 series panels per array with 3 arrays in parallel, 12 panels per CC, 2CC's.

    so there would be 1 array of Mits. and 2 of Luxen's on one of the CC's.

    The Mits. Array = 70.4V Vmp, 88.0V Voc, 6.84A Imp, 7.36A Isc
    the Luxen array = 70.4V Vmp, 86.4V Voc, 7.39A Imp, 8.69A Isc....no problems here so far, each array is 4 in series and they are all matched panels

    But what happens when the array outputs are combined? the Vmp's match but the Imp does not?
    Will the lower Imp be what the CC 'sees'?

    Should I reassign the 4 Mitsubishi panels to another job?
    100% Off Grid @ 51* 46' N lat 124* 44' W long

    New House system: coming - 2 arrays @ 2240W
    CL150&Epanel 2 @140 W 12v PVs , 24V C&D AT-15P AGM @ 950Ah
    + CL150 2@120W 12 V panels, 24V C&D AT-15P AGM @ 950Ah
    Cotek ST1500W inverter, TBS 30a-24v Omni-charger, Honda Eu3000is,

    Guest cabin system: 3 - 70W panels to SB 2000e CC, with 2 - 100 ah 12v SAFT wet NiCd's , 600W TSW Inverter

  2. #2

    Default Re: Combining differing Series Arrays

    No worries. The Imp only matters in the series connection, just as the Vmp only matters in the parallel one.
    So four of the Mitsu's in one string and four of the Luxen's in another one or two will be fine. The Imp's aren't that far apart here either. If it was a really big difference, fuses would prevent the higher current panels from frying the lower ones if something should go wrong.
    1220 Watts of PV, OB MX60, 232 Amp hrs, OB 3524, Honda eu2000.

    Ohm's Law: Amps = Volts / Ohms
    Power Formula: Watts = Volts * Amps

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