Victron RS450/200 smartsolar - MPPT string voltage Voc

I try to understand this solar charger but i am confused by the numbers that i see for this charger
It should have max.450 DC volt,with REC 410 W panels is max.9 of these panels
It got 4 trackers and every PV string should have max.7200 Wp
This look me contradicting or do i miss something
Can someone explain where i get wrong

You are Not using enough words to better explain Exactly the Quantity of Panels you have & wording is a bit incorrect.

However, I am assuming you have 9 panels on each Tracker & all the panels are 410W each ?
If so, 9x 410W = 3.69kW per Tracker x 4 = 14.76kW PV Array.
If the Closed circuit DC Voltage Commonly for a 410W Panel will only be around 36V DC !
So, 9x 36V =324v DC if ALL the 9 panels on the Tracker are configured is Series!

In Sydney on a clear Day, a DAT Tracker we Generate 11 hours of Peak energy, and if my figures above are correct, you System should be Generating approx. 162kWh of Energy per Day, less Conversion losses of your inverter.

Thanks TheRaptor
At the moment i have only a fixed array from 4,2 Kw and that’s enough for my needs here in Europe
But i gone relocate to Philippines and build there a new one,off grid so i am searching for the material and how to diy
I tought on all 4 trackers you can have only 450 Dc all add up ,so max.450 not 450*4=1800…
Max.that u can use on this Mppt is 11520W solar panel so i cant and use all the way 9panels
Voc is 49 V and the Vmp is 42,7 V,and i need the Voc for counting the panels…
Do you know if you can use 3 trackers for serial connected an 1 parallel at te same time
D.a.t. Is not possible i am surrounded by threes not high but to high for D.A.T.and only fixed array is possible

You need to do a more research on what system you actually want to build!

As a lot of what you are saying does Not make much scene, as if you are surrounded by Trees, Fixed Solar Panels will be Fare worse off than a DAT, as a DAT chases the Sun or the brightest area of the sky!

As a Dual Axis-solar Tracker (DAT) can be manufactured with a 6mt high Mast to get above the Trees, these are designed to hold approx. 30 solar panels, but obviously the main Racking can be manufactured to just hold say 8 solar panels.

What are you calling a Tracker ?

As for Calculating the DC Voltage, only the Maximum Power Voltage (Vmp) is used, as the Voc is the Open Voltage when Not connected to anything.
So, 4 x 42.7V DC = 170.8V DC

If you Divide 450V by 42.7V =9.53 Panels.
So, 9 Panels is the Maximum Panels connected in Series, will be Under 450V DC, if that is the limit of the Inverters specifications !

The OP is clearly talking about MPP tracker, not dual axis tracker.

This is more of less right. There are some other variables that should be taken into account, like min. temperature of your location. But Philippines won’t get too cold presumably, so probably not a big factor. I would pay a solar designer to do the calculations for you. You can DIY it, but a simple error will cost you a lot, it’s probably worth the investment to get a professional system design done.

Ah, that makes more scene, if one used the correct terms, the meaning would not gets lost in Translation !

95% of all Dual Axis Trackers (DAT’s) are installed on Rural properties & Behind-the-Meter & Off-Grid.

I am always amused by all the Hype of getting a Professional to Design a System !
Although, you are correct, that most Retailers/installers should start Designing & installing solar Panels so that 1/3 are installed to the East, 1/3 to the North & 1/3 to the West (if possible), then this industry would NOT have the Mid-Day Energy Spikes, that is said to causing sub-station to “Trip out”.

Residential Roof mounted Solar Arrays are such a simple installation, just require two panel Railing per string of panels, a DC disconnect switch next to the racking, under a UV cover, and Conduit run back to an Inverter.
Fitting the Railings to a Tin Roofing is really simple job for a Roof Plumber/labourer, Tiled Roofs are a little more complicated, as one needs to be careful not to break any Tiles.

A competent Electrician should be able to install the inverter and a set of DC & AC disconnect switches in under an hour …or two!

I only answered this post as I considered his cost was excessive, but that is only my opinion !

This industry need to drag it’s self into the 21st century & Stop selling way oversized Arrays, and start installing Energy Storage with every Micro Grid!

As @the_uglydog as made clear in other threads Offgrid solar and batteries | Philippines, competent electricians are not always easy to come by. By design I am referring to the electrical wiring. A simple mistake in buying the wrong inverter for your needs, or worse wiring the whole system up, and then finding out it keeps cutting out, can be incredibly time consuming and costly.

Most users on this forum are new to solar, they won’t know the correct terms.

I agree with you totally, there are Cowboys out there Marty, and the few bad ones make it look bad for the Real professionals.

I’m Not a qualified Electrician, but at my age I have over a dozen disciplines under my belt.
I am a road scholar, as everything I have learnt was on the Road of life ! :sunglasses:

That is why I come here to Educate those people !

Thanks Marty
For me it’s clear that i was talking about the 4 Mppt trackers on this solar charger
But i did not know what to use Voc or Vmp, and if it was let say 9 panels,is that for 1 Mppt tracker on this solar charger or 9 for the 4 Mppt tracker all together
I know that i need a designer for this but when i look all around you need to understand what they are telling ,they should be competent but is that always so…
I contact 2 designers,at the moment no replay,i wait another week and try again
And for the cowboy i am,i build my house 30 years ago, including plumbing,electricity and 15 years ago put my solar system on it
ok it was 1 string 4,2 Kw solarpanel Sma and breakers,easy but for offgrid and DC i need advice and designer to do this
It’s easy to blame someone but i never talk from double axis tracker and easy to tell that this is the only good thing
And if you know a designer for this,he can contact me always

I thought I would jump in and add some advice… Always use the panel Voc and take into account Voc for your location based on the lowest temperature (early morning). Generally, if you add 3 to 4 Volts to the panel Voc you will be very safe, unless you are in an extremely cold climate you may need to add 5 to 8 volts to the panel Voc, depending on the minimum temperature?

Also, refer to the manufacturer’s specifications and guidelines as they have these for a very good reason. I would say never go beyond these limits unless you are very experienced and have asked the manufacturer directly, plus you have adequate circuit protection in place.

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Also, remember to read the notes at the bottom of the spec sheet as these define certain conditions that affect the operating voltage! For example, in this case, you should not exceed 8 x the battery float voltage… So the max Voc could actually be around 420V, not 450V.

Thanks Sparky
Normally the temp.go not below 24* so with regarding Voc from 49v for this panel i should put 8 panels in a string so max 3280 w,with temp.coefficient no problem
But i see there in the specifications with the max.DC output charging power that there’s a limit from 4000W per tracker and a total of 11520W
Does this mean that you can have 3 trackers with 8panels and for the last one a limit from 1580 W
Sometimes i read here that when you have a400W panel the max out voltage is let say 350V with all the losses or can you bring this not in account and use only the numbers in the specifications
I ask this because the 2 strings gone be south and 1 one more west oriented and the last one NE or E for in the morning so maybe i have the max power at the all time

Yes, in this case, you should use a maximum of 8 x 410W panels per string (3.28kW).

The 11.52kW rating is the maximum total charging power, not the maximum solar array size.

You can connect 4 strings of 8 panels with no problem, especially if they are all at different orientations. Yes, as you mentioned there are several loss factors that will reduce the power so oversizing the solar array is very common (as long as you do not exceed the input current and voltage limits)