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donnib avatar image
donnib asked

LOM detection when feed-in disabled why ?

Hi,

I read https://www.victronenergy.com/live/ve.bus:grid-codes-and-loss-of-mains-detection :

Q4: I use ESS, but have disabled feed-back, is a grid-code still required?
A: Yes, also in this case LOM is required to make for a safe and also local regulations compliant system. Running ESS with disabled-feed-back is still not the same as using a Multi in its default configuration without ESS.

I don't understand why do i need LOM for this ? Can somebody explain ? I want to make an off-grid solar system (using Multiplus II and SmartSolar and Venus GX) and ONLY pull from the grid in case i don't have solar/battery.

/donnib

Multiplus-II
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2 Answers
Murray van Graan avatar image
Murray van Graan answered ·

In a case like this, instead of ESS rather look at using dedicated ignore AC input, or the generator assistant to control when you want to use AC.

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donnib avatar image donnib commented ·

@Murray van Graan thank you. What do you mean by ignore AC input? How would one doar that ?

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Murray van Graan avatar image Murray van Graan donnib commented ·

In ve.config is a page called virtual switch, where you could set up ignore ac input using battery SOC, battery voltage or load Values to determine when to use the ac input and when to ignore it.

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donnib avatar image donnib Murray van Graan commented ·

@Murray van Graan thank you for the reply so i am a bit confused. The reason i am confused is because i am not sure if i can accomplish what i want with a system like described above. I read the documentation and btw there is so much of it. At the moment i only have my solar panels and i am investigating what Vitron parts i need and i identified the above. I don't have anything else such as inverters or other things.

"All" i want is that i can pull/mix power from grid when i don't have battery/solar but NEVER feedback to the grid. I assume feed-back and feed-in are the same things right ? I don't know if i need ESS or ignore AC input or both if that's possible ? The most important thing for me is to not feedback to grid and be able to pull and use the produced energy myself.

I was kind of hoping there was a recipe for what kind of hardware i would need to do that and if it is indeed possible.

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Murray van Graan avatar image Murray van Graan donnib commented ·

Hi @donnib. What size system are you planning? This will determine how it’s set up. If you use the dedicated ignore ac input function, you will run that alone and not use ESS. ESS is intended for systems that are connected to the grid permanently.

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donnib avatar image donnib Murray van Graan commented ·

I just bought 20pcs of 310W panels (https://bit.ly/2P1GL9O) so i was thinking to place 10 on each side of the roof meaning i would do 2 x 5 panels in series so i would have 200v for 5 panels then parallel the 2 strings and one string is 10A so 200v 20a for one charge controller. I think that is ok but that means i need to use the 250/60 solar charger model which is more expensive and i need two of those.

In regards to grid, i do have 100% stable grid connection and since the Multiplus II can handle a big load in by pass (as far as i understand, correct me if i am wrong) i can practically run the whole house on the AC out from the inverter.

Regarding usage, we have roughly 16-20kw consumption per day and in total 6000kw. I am also working on building a powerwall myself using LiFePo4 batteries and i hope i make roughly a 10kwh.

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donnib avatar image donnib donnib commented ·

@Murray van Graan did you have a chance to look at my reply ?

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lyric avatar image
lyric answered ·

Did you ever build/set-up a system using the multiplus-ii in Denmark? I am reading up on this and have a similar wish as you.

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donnib avatar image donnib commented ·
Yes i did, my system runs for quite some time in DK
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peter-popaleny avatar image peter-popaleny donnib commented ·

Hello Mate,

I would like to do exactly same as you:” ONLY pull from the grid in case i don't have solar/battery”

Can you advice your solution, please?

thanks a lot, Peter

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