Combining differing Series Arrays

westbranch
westbranch Solar Expert Posts: 5,183 ✭✭✭✭
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'?:cry:

Should I reassign the 4 Mitsubishi panels to another job?
 
KID #51B  4s 140W to 24V 900Ah C&D AGM
CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
Cotek ST1500W 24V Inverter,OmniCharge 3024,
2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
West Chilcotin, BC, Canada

Comments

  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
    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.