July 9, 20242 yr Hello, I've currently got an 8kw Sunsynk Invertor with 9x 425w panels connect in series to one MPPT, I plan to add another 2 which would bring me to my limit of 430v on the invertor MPPT port I also plan to install a further 12 panels on a chicken shed / bird aviary connected in two sets of 6 paralleled does anyone foresee any issues with running the higher voltage? The bank of 2x6 panels will be approx 40m away from invertor using 6mm cable
July 9, 20242 yr 1 hour ago, chessmaster said: Hello, I've currently got an 8kw Sunsynk Invertor with 9x 425w panels connect in series to one MPPT, I plan to add another 2 which would bring me to my limit of 430v on the invertor MPPT port I also plan to install a further 12 panels on a chicken shed / bird aviary connected in two sets of 6 paralleled does anyone foresee any issues with running the higher voltage? The bank of 2x6 panels will be approx 40m away from invertor using 6mm cable Post the panel specs. My estimate is 11x425W the voltage is too high for comfort. Also supply the expected min temp in your area for the last 5 yrs.
July 9, 20242 yr Author 10 minutes ago, Scorp007 said: Post the panel specs. My estimate is 11x425W the voltage is too high for comfort. Also supply the expected min temp in your area for the last 5 yrs. Uk based in the south. 2 degrees is the lowest temp during day in the last 5 years Longi HiMo6 HTB 425W All Black Mono Electrical Peak power 425W Vmpp 32.96V Voc 39.23V Impp 12.90A Isc 13.93A
July 9, 20242 yr 17 minutes ago, chessmaster said: Uk based in the south. 2 degrees is the lowest temp during day in the last 5 years Longi HiMo6 HTB 425W All Black Mono Electrical Peak power 425W Vmpp 32.96V Voc 39.23V Impp 12.90A Isc 13.93A Your voltage could rise to over 450V on cold days and that is too high with 11 panels. 10 panels should be fine on the string with 9 currently. The new strings seems OK to me.
July 9, 20242 yr Author Thanks Wouldn't the max dc input value of 500v apply here though meaning ok? Or should I be looking at the max mppt value of 425v?
July 9, 20242 yr 1 hour ago, chessmaster said: Thanks Wouldn't the max dc input value of 500v apply here though meaning ok? Or should I be looking at the max mppt value of 425v? Yes you are correct. Sorry for the mistake. I thought the maximum was 450V. I should have asked for the inverter specs as well.
July 10, 20242 yr @chessmaster, I'm with @Scorp007 on this. Even though the max is 500V, if you read the inv. specs 2 lines down, [mppt range = 125 -425V], it implies that 425V is the maximum usable voltage for this mppt tracker to still operate efficiently. Therefor I would go with 10 panels max. per string. But that's just me.
July 10, 20242 yr Author Thanks guys, I think what I will do is stick with the 9 panels connected to a single MPPT at 353v, then wire 14 panels in two strings paralleled giving me 274v (27amps) to the other MPPT, to effectively use all 23 panels I have
July 10, 20242 yr 37 minutes ago, Sidewinder said: @chessmaster, I'm with @Scorp007 on this. Even though the max is 500V, if you read the inv. specs 2 lines down, [mppt range = 125 -425V], it implies that 425V is the maximum usable voltage for this mppt tracker to still operate efficiently. Therefor I would go with 10 panels max. per string. But that's just me. These panels are low voltage panels as oppose to panel with Voc of 50+ volts Vmp is 32.96, 11*33=363 , 11 panels will be in safe range. Voc is 39.23, let say 11*40=440 , again Voc is under limit, arrangement should be fine.
July 10, 20242 yr 28 minutes ago, rastert111 said: These panels are low voltage panels as oppose to panel with Voc of 50+ volts Vmp is 32.96, 11*33=363 , 11 panels will be in safe range. Voc is 39.23, let say 11*40=440 , again Voc is under limit, arrangement should be fine. But bear in mind the Voc of 440V for 11 is at 25° and will increase to nearly 465V at say 2° on very cold days. Rather save than sorry is the line we tend to take.
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