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andre12 avatar image

Victron Multiplus 2 48/5000 question about Mppt and batterie

Hello,


I'm planning right now a Solar System as a island with power suport from the grid with following components

Victron Multipluss II 48/5000

MPPT Victron 150/100 MC4

Solarmodul 15 pieces Trina Solar 375WP MONO Halbzelle TSM-DE06M.08 (II)

3 rows 5 parallel connected


VENUS GX Raspberry Basis

EM24 Energy Meter DIN.AV.3.X.IS.X


at first is the 150/100 Mppt the right size for the Solar-panels !?

can i run the system at first to start without a batterie backup


Bye Andre

Multiplus-II
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4 Answers
andre12 avatar image
andre12 answered ·

I have another Question.

I was reading about the factor one rule The max PV power must be equal or less than the VA rating of the inverter/charger

on this site https://www.victronenergy.com/live/ac_coupling:start#minimum_battery_capacity


should i install only at all 5000Wp Panels !?

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@Andre12

That rule only applies to ac-coupled pv inverters. You'll have a dc-coupled charger, and it will be fine as you've described. (I'd prefer it that way).

If you have special needs though, best mention them before buying anything.

what happens to the Power i don't need, is the mppt stopping producing the power ?


@Andre12

Yes, it isn't harvested. The mpp is no longer tracked, and the panel V rises, at the extreme end approaching the Voc of the panels.

It is possible to export to grid, but this is much more complex, and usually requires an experienced local installer to sort the details.

JohnC avatar image
JohnC answered ·

Hi @Andre12

I read your question as having 3x of those panels in series (a "row") and 5x paralleled. So '3S5P' we'd often call that. And it would work fine with a 150/100.

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Andre, Sorry about that. John is correct.


I was miss reading thinking 3 strings of 5 in series


however if you have 3 rows and 5 in parralle per row thats 1875 still per row and the total row voltage is 37.5 volts.


I presume you are then connecting these 3 rows into series so its 3 x 42 volts thats 126 volts. yes that will work.


I personally think that doing 5 in series then the 3 rows in parallel would be better as the string voltage total is higher and would give better output on overcast days.

but your call there


again sorry for the confusion on MY part

andre12 avatar image
andre12 answered ·

Thanks for the answer.

i was calculating the mppt with that https://www.victronenergy.de/mppt-calculator and it showed up that i need a 150/100 MPPT

i'm wondering why ???


if i Install at first one Phylontech with 2,4kw is the system then running and Turning the power that i need from the mppt direct into 220V of the house System


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Yes it will do that if setup correctly.

anyway look at your Solar panels OCV string voltages in total for that string they must NOT exceed the Regs Rated value


15x 375 is 5625 so divide that by 3 we get 1875 per string then 5 in a string 1875/5 is 37.5 volts a panel

5 x 37.5 is 187V per String and thats the working voltage, the Open circuit will be higher maybe 40 or 42 volts

you must get a 250/100 MPPT unit, this should be fine for you


Paul B avatar image
Paul B answered ·

you have to have some battery to start the inverter and the MPPT.

your panels have a total power of 5625 Watts

now the OPEN circuit volts are of concern as you have not mentioned each panels OCV presuming 36 volts then 5 x 36 is 180 volts. BANG goes your MPPT controller, you need a 250/100


I would sugest a Cerbo instead of a venus, much newer unitr more powerfull more options for future you very similar costs


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