Hi, I’ve got a question for Victron system creators or users. I have 3x Multiplus II 6k5 in three-phase connection, SmartSolar 250/100 and two strings of AIKO Neostar 2S+ panels with Isc (maximum shorted current) 14.2A each. Those strings are joined before entering regulator, so total current can be 28,4A or less in SmartSolar. In cold weather there can be 0.05% dfifference maybe, so we can ignore that I assume. My problem is with VRM chart “Solar Charger PV Voltage And Current” - it shows many peaks of current and some of them are higher then is the possible maximum - e.g. 33.1A. And more - there are 15A current fuses on each string, so I’m pretty sure the current doesn’t exceed that value in reality. So why does the chart show such values - is that some kind of estimation or calculation inaccuracy ? Thnx for any advice.
15A fuses won’t do anything, typically fuses need almost 2x their rated current to blow in a reasonable time, see here.
If the sun is very bright you can get a little bit more than the rated current/power out of solar panels, though 33.1A out of panels with Isc=28.4A seems like too much…
Isc is quoted at a specific standard solar irradance, typically 1,000W/m2. Sometimes you can get cloud edge effect where your panels see the full sun but there is a cloud near the sun and some extra irradiation reflects / refracts off the edge of the cloud so the panel sees additional power in therefore it is possible to occasionally see higher than Isc.
And put simply watts = voltage x amps
…
155Vx33A = 5115W = 200V x 25.5A
Its not tracking at ISC but at max powerpoint
I don’t understand now what you mean - those current and voltage values are not actual values in cables between panels and regulator, but they are somewhere inside DC-DC converter itself?
What was the wattage the pv was producing at the time?
Don’t know exactly now, but was much higher than maximum possible by panel specs too, that’s why I started checking what’s going on
Load the widget in the VRM and the graph you showed can be compared directly to the PV yield, of you lay them out buly each other.
Look at the wattage.
How many panels do you have in total?
A 15A fuse is quite close to the rating of the panel. Usually its sized 1.25x above (17.75A rounded up to 20a). I see the panel manufacturers day 25A max per string.
There are 10 panels in total (2 strings with 5 panel each). You are right about the fuse size, I purchased 15A fuses because I planned different types of panels at first (CanadianSolar with 10A Ics), but after that I changed my mind and used these AIKO panels, simply because I could get them in local store. I will buy higher current fuses soon just to be safe, I just wandered how is it possible to exceed Isc on panels.
And you still haven’t said what the wattage is.
If they are 10x 500 watts then you have roughly 5000 watts available. That being said when colder they can actually have a slightly higher wattage.
Watts is volts x amps.
It is quite normal for the amps to be higher than the imp of a panel. Yes if you put a clamp/amp meter there those amps are actually there.