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Over paneling Victron 250/100 verification

rhino

Solar Wizard
Joined
Jun 6, 2020
Messages
2,554
Location
Minnesota
I wanted to double check that there wouldn't be an issue adding additional panels to my array. It has 2 strings of 5 in series Kyocera KU265 which has specs of:
  • Vmp: 31.0 volts
  • Imp: 8.55 amps
  • Voc: 38.3 volts
  • Isc: 9.26 amps
So that array has Voc of around 191.5 + temp adjustment and Isc of around 18.5A

I have 25 used CS6P-255PX I got from SanTan Solar with specs of
STC Rating255.0
PTC Rating234.3
Open Circuit Voltage (Voc)37.4 V
Short Circuit Current (Isc)9.0 A

The array is about 600ft away using 2AWG AL so there will be noticeable voltage loss after increasing the amperage.

The Victron 250/100 says not to go over 70A Isc and has "nominal" 5800W array size for 48V battery.

My calculation shows these panels would be Voc of 187V and Isc of around 36A for 4 strings.. adding these 4 new strings to current array would then have total Isc of 54.5A. Total STC rating of all panels in this array would be 7750W. I assume controller would see a lot less than this due to line loss and the other panels being used. The new set of panels may also not be pointed exactly same direction.

Any issues doing this?
 
Victron has a tool you can use to check if what you're proposing is OK. The links below are to the Resource section where you'll find this and many other helpful tools and reference material. (I tend to prefer the Excel spreadsheet version of the Victron MPPT tool over the online version so I can save off various scenarios.)


 
Victron has a tool you can use to check if what you're proposing is OK. The links below are to the Resource section where you'll find this and many other helpful tools and reference material. (I tend to prefer the Excel spreadsheet version of the Victron MPPT tool over the online version so I can save off various scenarios.)


Thanks for the links. The design tool says it is ok but it doesn't have all the details and just wanted to know if overall what I want to do makes sense given different modules, distance, etc.. To me it looks good and the tool says it looks good but just wanted to be verified by another human :)
 
Actually when I did click on the Excel spreadsheet one it actually is a blog post with a very detailed explanation of over panelling and examples.. I thought it was just a link to download the excel spreadsheet.. they have a lot of this info hidden! https://www.victronenergy.com/blog/...ar-modules-to-the-new-mppt-charge-regulators/
Oh yeah, I forgot that's where the spreadsheet link was. That blog post is excellent and used to get a lot of mentions on the forum.
 
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