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hoogland avatar image
hoogland asked

AC COUPLED PV

Im basically a novice to victron here , i heard only good things about the victron community this far. I hope I dont get blasted for asking questions that are too simple for the experts here.

Ive just watched a video titled;

ESS (Energy Storage System) Webinar | 19 December 2016 | Victron Energy


I would like someone to explain what is meant by ''PV on the AC INPUT'' of a ac coupled system. Could someone show me via a more detailed wiring diagram what is meant by this , it reads confusing to me because it sounds like you're wiring pv wires to an actual ac input. I would like to see the actual terminals where the wiring of the pv would go into inverter setup like this .1685697607760.png

wiring diagram
1685697607760.png (49.0 KiB)
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matt1309 avatar image matt1309 commented ·

Hi @Hoogland


It's difficult to answer without typing paragraphs. Maybe a watching few more videos might clear things up. This explanation will be oversimplified (missing safety devices but will hopefully help clear things up a bit)

The AC coupled PV inverter isn't directly plugged into the Multiplus. It's just on the circuit that are also connected to multiplus on AC Side.


ie Your house distribution board has grid input. It also has grid tied PV inverter connected. And all of your loads run off this distribution board.

Then you decide to add a new circuit breaker and add a multiplus ii, this breaker would wire into ACIN on multiplus.

Assuming you have (supported) energy meters on grid coming into distribution board and also energy meter on PV generated the Victron system can use that information to calculate what power loads you're using need and output just enough power to cover them or take power in and charge batteries. Almost like the multiplus is feeding just enough power back up the line to cover your loads on the ACIN side of the inverter.


However if grid goes down the multiplus (and the AC coupled PV) will turn off to prevent exporting power out to the grid and hurting someone if they're working on the line.

Basic layout:

grid -> Loads + AC coupled PV <-> ACIN multiplus


If however you instead had the grid going straight into multiplus (before the house loads) on ACIN and had all of your loads connected to a different distribution board "after" the multiplus on ACOUT1 the loads will stay on if the grid goes down and you've essentially made you own mini grid. If you also wire in the AC coupled PV on ACOUT1 it will also stay on (have to adhere to factor of 1 rule)


grid <-> ACIN multiplus ACOUT1 <-> loads + AC coupled PV



I like to think of it as ACIN is "before" the multiplus and ACOUT is after multiplus. The only added confusion is the multiplus is smart enough to send power out to ACIN as well as take it in.



The ESS page might make things easier to understand:

ESS Quick Installation Guide [Victron Energy]

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hoogland avatar image hoogland matt1309 commented ·
Thank you very much. You have cleared a cloud over my mind . Im looking forward to learning more about the products on Victron and becoming part of the Victron community. Hopefully I can contribute to others on here too when have sufficient knowledge
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matt1309 avatar image matt1309 hoogland commented ·
I feel it's a bit more of a complex system than many other solar providers that i foud when i was originally shopping around but it seems to allow for much more configuration.


Odds are Victron system can be configured to exactly your need rather than having compromises which is what I found when I was shopping around for offgrid/true hybrid systems.


My advice would be watch a few youtube videos of electricians installing other solar systems (aim for residential installers as they tend to go for more plug and play systems that are often simpler but limited ie only work with grid power connected). You'll likely find yourself asking "wouldnt if be cool if this system could do xyz". Then when you re-read/re-watch victron documentation/videos you'll often see victron has that xyz feature and it'll click that much faster. (At least that's the route I took when i started reading up on these things. I'm not an electrician by trade and feel I have a decent understanding now).



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1 Answer
mvas avatar image
mvas answered ·

The "PV Inverter" in your diagram, is called a Grid-Tie Inverter.
Below is a link, (older article) AC COUPLED diagram, showing how a Grid-Tie Inverter can
be combined with a Victron MultiPlus or Victron Quattro ...
NOTE: The PV wires connect directly to the Grid-Tie Inverter and/or
the Victron MPPT Charge Controller.
AC-Coupled-Diagram

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