question

donnib avatar image
donnib asked

MultiPlus II disable feed back entirely possible ?

Hi,

I'd like to get a MultiPlus II and use it with PV and SmartSolar, can i setup the MultiPlus to throw out any excess energy made by the PV since i don't want to feedback to the grid but just consume from the grid when i don't have solar energy or battery.

/donnib

Multiplus-II
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2 Answers
Nicholas Wessels avatar image
Nicholas Wessels answered ·

Yes this is 100% possible as long as have a CCGX or Venus GX running the ESS assistants.

In fact this functionality was specifically coded by Victron many years ago for users like me in South Africa where we are unable to feed into the grid.

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JohnC avatar image
JohnC answered ·

Hi @donnib

Your kit will do that outta-the-box. The Multi doesn't dump the energy, the mppt stops harvesting it. And it can't feedback to the grid unless you have the kit to tell it to do so.

If you can live with a simple on-off switch on your grid input, then just turn it on as you need.



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donnib avatar image donnib commented ·

What do you mean by ?


If you can live with a simple on-off switch on your grid input, then just turn it on as you need.



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JohnC avatar image JohnC ♦ donnib commented ·

When your batts are down, and no solar, just switch on the grid to handle loads and charge batts.

Perhaps you're talking a different type of system, like a UPS battery? You do know you'll need a batt with the kit you describe?

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donnib avatar image donnib JohnC ♦ commented ·

Yes I do know about the Battery. I understood that the inverter would do bypass and take from grid no?

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JohnC avatar image JohnC ♦ donnib commented ·

Yes, it can take from the grid to bypass. Also charge batts to whatever level and how fast you want. Or restrict grid and 'Power Assist' with batts. But the base system cannot feed back to the grid..

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donnib avatar image donnib JohnC ♦ commented ·

Ok so per default it won't feed back to grid, now that we are at it, what does it require if want to do that at some point ?

So does the multiplus 2 adjust it's phase so it can quickly switch to the grid when needed or how does that happen in practice ? Especially i am interested what happens when solar only provides 500w, battery can provide 1kw and i have a consumption of 3kw, can the Multiplus get the remaining 1,5kw from the grid and when no solar and battery is left then run all consumption from the grid. If it can do that then it has to sync with the grid right ?

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donnib avatar image donnib donnib commented ·

@JohnC or somebody else where can I find answers on above?

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JohnC avatar image JohnC ♦ donnib commented ·

Sorry, I missed your last question.

To feed back to the grid you'd need permissions/certifications, etc. Then you'd look to ESS software: https://www.victronenergy.com/live/ess:design-installation-manual

And of course the necessary hardware if you don't already have it. Notably a GX box.

For a simple system like you first described, ESS wouldn't be necessary, probably not even recommended. But could be added later.

The Multi will indeed sync to the grid supply (or a generator), even with a 'soft-start' functionality if you choose to use it.

How you balance-out your loads and supplies is up to you, and there are various ways to implement differing needs. But many of the best require GX functionality.

And to that end, I'd suggest you seriously consider adding it. Even if in a Multiplus II GX (limited product range thereof).


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donnib avatar image donnib JohnC ♦ commented ·

@JohnC sorry for the late reply (been on vacation) and thank you for the reply (same to you @Nicholas Wessels ) so let me try to put down what i have understood :

With following HW: Multiplus II 5000, Venus GX and two SmartSolar 250/60 chargers. So with this system i can pull from the grid but disable feed-in to the grid since i am not allowed. Correct ? From @Nicholas Wessels comment bellow i understand that ESS will supplement from grid when necessary but do i need a meter or something else than above to be 1000% sure i don't feed back to the grid or is that enough by just disabling the feed-in on the GX device ?

/donnib

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Nicholas Wessels avatar image Nicholas Wessels donnib commented ·

Hi @donnib - this is standard functionality using the ESS settings with the Multiplus. It will always use maximum PV (solar) that is available, then batteries, and supplement the rest from the grid. This happens by default.

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obay avatar image obay JohnC ♦ commented ·

dear u r wrong my multiplus feedback to my grid (returning back to ac in when grid is off ) and the setting of feedback is default that dont allow feedbacking

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