question

@ice77

If you have a GX then the system co ordinates charge amps and each tracker will produce what it needs to to meet the demand.

You get 4 trackers if you get 2x450/100 or 450/200, so that is not a valid point. your 450/200 would track each tracker the same way anyway? If one array was receiving less irradiation it will produce less, that is the way of things in solar.

Install space is larger for two units as extra space needs to be given for heat there. So space may be a consideration; but two separate units is also an advantage to avoid unit heat derating.

It would also increase cabling costs slightly as the runs will be slightly longer since the spacing is necessary.

I am a person who does not like all the eggs in one basket, so to speak, if it was the only MPPT in my system (in larger systems with three to four it is less of an issue). So personally in the system I would use the 2x 450/100 option. (if I had space)

ah ok - so the 200A are not given over the sum of all 4 MPPT Trackers.

Did I understand right, that technically the 450/200 has no advanage ... no more options to get more power out of the 4 mppts.

To be honest, I did already buy 2x 450/100 but a friend of mine told me that I did an error buying 2 seperate units. He told me, that the 450/200 has the advantage that it sums up the power over 4mppts and there could be situations (how my example 120A and 80A oder 2 mppts) that the single 450/100 has to cut of to 100A and the 450/200 has the possibility to add 120 and 80A to 200 and does not need to cut of anything.

Only for this i was thinking about to send the new 450/100 back and buy an 450/200. Not for saving money ... only to get the better technical solution.

thank you so much for answering

ice77

Go for redundancy, always important!

I just had my MK3 programming cable dying on me within 14 months and now I'm stuck with programming my MP2 5000, grrr

I think the main question has not been answered yet.
After all, the question was about the limitation of the output current.
Assuming that two strings deliver more than 2.88 kW each and these are both connected to a 450/100, this regulates down.
If these two strings were connected to a 450/200, the full power would be available.
Of course, the strings can also be routed to a 450/100 with a smaller or enders aligned string.

I would combine the north/south strings in one RS450-100 and the E/W into the other RS450-100. If the east string has high output, the west string doesnt and it is equal to N/S combination. If you combine e.g. east and south, the probablity of limiting the output circuit is higher in the morning. If you combine west and south, the probability of limiting the output circuit is higher in the evenning.

There is an excellent introduction of understanding the power losses from east-west mismatch by Fronius. Unfortunately, I know that document only in German

https://docplayer.org/119171-Ost-west-ausgerichtete-pv-anlagen-mit-nur-einem-mpp-tracker.html

Anyhow its a common problem to match the input and output power of the RS450 inverters where I also stuck for the moment. I am going to open another thread therefore.

Never mind that some people are claiming the 200A produces more power this is totally false.

The main point is it's better to spread the production over 2x 100A controllers then you have 50% power if a controller goes down, it's that simple. I have 2x RS 450/100 with arrays split SE & SW and on the odd occasion the battery has not reached absorption by mid day I see (using a clamp meter) 108A produced from each controller even though they report 100A in the VRM and remote console.