Im confused over the panel configuration for a RS 450/200 or multiple of where I have 48 panels. The calculator says if do 8 strings of 6 panels over 2 x 450/200 mppt or 6stings x 8 panel over 2 x 450/200 mppt i will harvest the same amount of energy over the year from both string configurations, however another Victron calculator after 6 panels it maxed out the 80 amp limit on that tracker X4 , then after that I am assuming its limited to 200 amps over the 4 (so 50 amps each)
I see the benefit in keeping the voltages higher towards the 450v for clouded days but the extra panels per string do nothing in output on the calculator in the current field graph when you add the seventh and eight panel.
Am i better of working with smaller individual MPPT’s like the 250/100 and spreading my panels across multiple of them at lower voltages (less panels in the string) rather than using the larger rs450/200 or the rs450/100.
475 watt
VOC 36.44
ISC 15.85
IMP 15.26
VMP 31.13
T Voc .24
T Pmax .26
T Isc .046
Thanks for any guidance for choosing the better victron product
The larger RS 450/200 inverters are probably the better choice. The system would probably use 2 450/200 vs something like 8 250/70. Both are possible of course.
There are indeed 2 limits, the amount of power that one tracker can deliver and the amount of power that the whole device can deliver.
Me personally i would prefer the tracker being able to pull all the power (6 panels/tracker) and only get some clipping if the total amperage of the output is 200A. This way i only lose about 10% output when all panels are at max output. In those situations 10% is probably not a dealbreaker. This is especially true if the strings have different orientations as they then never have max output at the same time. Actual max output of the inverter is also related to the battery voltage; 200A means 9600W at 48V and 10240W at 51.2V. This may make a difference in your decision.
So reading a bit and with refrence to your reply being that the panels are all facing the same which i failed to say, and using the victron xcell calculator and the victron mppt calculator am i looking better off using the 250/70
This offers keeping my voltages higher in the trackers max range of 197v to 175v mpt with a voc 230v and a lower start up limit than the 450/200 offers. Current on the 250/70 is 56 to62 amps due to temp differences.
Compared to
The RS 450/200 only offers same voltages as same strings but i max out at 200 amps due to all strings facing same orrientation.
Thinking i am better off with 8 of the 250/70 due to 6 to 12 amps output x 8 = 48 to 96 amps extra than the 450/200 due to its max out at 200.
Battery charge current can take 200amp each x 3
Float is 53.6vdc
48 panels
Can i please be advised if im thinking correct with this additional info.
I apreciate the feedback and learning from your replies.
Having both a 450/100 and 250/100 I would recommend the 250/100. Simply because you can get the full 100A output from the single tracker. Versus with the 450/100 you run into the 4kW per tracker max limit so you have to run a second home run string to maximize the output from the scc. You also get much better bang for buck with 250/100 over 450/100, when looking at $ per charging A.
In the case of the 450/200, you need to run at least three home run strings to maximize its output, versus two strings for two 250/100s.
Now the downside is the pv current will be higher on the 250/100s because you may need 3 or 4 parallel strings out at the panels to reach that 100A output. Will need combiner and breakers or some Staubli branch connectors and inline mc4 fuses. So you may need to upsize your pv wiring home runs to suit.
Potentially could use five 250/85 ve.can tr units, and run 5s2p on four of them and 4s2p on the fifth. That would keep your PV current at around 32A max. Ve.can so you can easily daisy chain them to cerbo.