Hi
I am connecting 12 panels to an easy solar 48/5000 and want to run 3 banks of 4 in series. The cable run from the panels to the easy solar is about 20 meters. I am using 6mm cable. The panels I am using are as below which give voc of 151.6 and MPPT voltage of 121.6. Is a 1% over voltage acceptable?
| Maximum power Pmax | 250 | Wp |
| Open circuit voltage Voc: | 37.9 | V |
| Short circuit current Isc | 8.65 | A |
| Maximum power point voltage Vmpp: | 30.4 | V |
| Maximum power point current Impp: | 8.24 | A |
Hi @davenrea
No overvoltage is accepted for any MPPT or other solar inverter.
Please be advised that your solar panels will produce much more voltage than Voc when temperature is under 25C.
BR,
Mihai
Can I ask if you are answering this as an employee of Victron? 1% in my mind is very small.
Thanks
Dave
I am not.
You have 1% overvoltage at NOCT (normal operating cell temperature) but at lower temperature is not uncommon to have 10% more voltage.
Please read full specs for your solar panels and you'll see that there is another very important parameter named Temperature Coefficient for Voc with the value around -0,2...-0,3% per grd K
Yeh, I'm not a Victron employee either, but I'd wire them 3S4P too. I have one of those boxes as well, and it's not the sort of thing I'd like to have to take back under my arm to the Victron shop and be told my warranty is void.
Look again at that 6mm2 cable too. Yes I know it's standard fare for residential grid tied stuff, but those guys are running like 4x or more times the V you will be.
Take care Pal. Look after that big blue beauty.. :)
Both, thanks for the replies, I will run 3S4P as suggested to be safe. I did some calcs and the loss was under 1% on the cable run of 20m (total cable run not distance to panel) on the panels it works out at 10mm, I will actually use double runs of 6mm as i have rather a lot of it spare along with the connectors! As you say got to Look after that big blue beauty, running quite a few of the Victron now, very good kit i find and Victron are very good when it comes to warranty.
