should i take STC or NOCT voltage/wattage in consideration when calculating the max panel possible for my Inverter?

mahdi89

New Member
should i take VOC or Vmpp voltage in consideration when calculating the max panel possible for my Inverter?
-Inverter max wattage 6500w PV
-2 Mppt 3250w each
-Mppt Range max 425
-Pv input max 500v

solar panel datasheet attached

can i install 20 panels (450w) on my system considering that the 450w is only the advertising wattage while the real wattage is way less??
 

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MisterSandals

Participation Medalist
What is panel Voc and SCC max input voltage?
And what is lowest temp your array will experience?

Are you using a solar charge controller or (grid tied) inverter?
 

MisterSandals

Participation Medalist
Panels rated at 25C so 9 deg diff.
Do your panels list temp coefficient? Using 4% in my calcs…
49V x .004 x 9 = 1.76V

MPPT max is 425V so let’s use that
425V / 50.76 = 8.37 panels for MPPT range
500 / 50.76 = 9 panels for SCC limits

20 panels not convenient.
9S2P for 18 panels.
With 1 more panel could do 7S3P
 

mahdi89

New Member
Panels rated at 25C so 9 deg diff.
Do your panels list temp coefficient? Using 4% in my calcs…
49V x .004 x 9 = 1.76V

MPPT max is 425V so let’s use that
425V / 50.76 = 8.37 panels for MPPT range
500 / 50.76 = 9 panels for SCC limits

20 panels not convenient.
9S2P for 18 panels.
With 1 more panel could do 7S3P
can i do parallel?
as my Mppt is 11A only per Mppt
total 22
so 9 on one mppt and 9 on the other?
 

mahdi89

New Member
the inverter is 13A on each Mppt so i cannot do parallels right ?

scc of panel is 11.5A
 

MisterSandals

Participation Medalist
Photovoltaic input current (A)13A + 13A
Max. PV ISC (A)
16.5 A + 16.5 A​
Wow, thats odd. I have never seen anything like this.

Maybe somebody else knows. New thread asking about SCC input amp limits?
 
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