question

duswami avatar image
duswami asked

Clarity on AC pass-through on AC1 OUT

Am I understanding correctly the grid AC passes through the Multi AC1 OUT when the inverter is in charging mode ONLY?

Multiplus-IIwiringgridac
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1 Answer
ejrossouw avatar image
ejrossouw answered ·

It is one of the instances. When using the system as a backup system it will too as well as when pulling in power from the grid to make up an inverter load shortfall when in ESS self consumption mode.

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@ejrossouw ESS aside, since I'm not using it will it pass through AC automatically (to make up for a load shortfall from the pv or bats). For example, when DC coupled PV is insufficient will it automatically pass through grid AC if present or does that scenario need relays or assistants (not ess)?

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Normal operation is grid priority, drawing from batteries if grid insufficient. Grid will charge batteries when sufficient grid available.
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duswami avatar image duswami kevgermany ♦♦ ·
@kevgermany Got it, so I've got it running now and I See how it works, thanks.

So, now, if I want to 'supplement Grid' AC with DC coupled PV, what's the best method since I'm not using ESS, looks like Generator Asst is for PV coupled only.

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If you want to supplement GRID with DC PV you need to use ESS, this is the whole point of ESS.

You can trigger ignore AC which will disconnect the inverter from Grid and use Battery and PV to run loads but without ESS you can't use grid and DC PV at the same time.

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@shaneyake That's sad :( I can't use ESS because I'm in the US and the grid code is disabled. Not even with Assistants? No secret trick? :)
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Depends on your utility but you can use Other which will allow ESS.


As kevgermany said you can set input current low, 6A is the min on most inverters and then enable Power Assistant this will active the inverter whenever you draw more than 6A from grid. So would kinda work.

Where in the US are you? MN has a nice program to certify non UL listed installations for Grid export.

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@shaneyake I'm next door, in MI, our utility is Detroit Edison. They have a net-metering program, but I'm not interested in doing that, just exporting solar to myself for self-consumption. Although, curious how they certify that?

As for your comment "you can set input current low, 6A is the min on most inverters and then enable Power Assistant this will active the inverter whenever you draw more than 6A from grid. So would kinda work."

Are you talking about limiting the input current on the Multi?

As for using ESS in the states, are you aware of any useful links or documentation pertaining to that? I believe one of the requisites is using a CT on the incoming Mains, which I have (EM24 AVI6).

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The states vary so much state by state so don't really have anything other than talking to the utility themselves. MVEC was really helpful not all are.


You don't need to use a meter, you can have the loads on the output of the inverter and use it to sense.

Yes, limiting the Inverter input current but you will want to programmatically change the input limit depending on the SOC state and other factors. I used NodeRed to do all my automation.

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I've looked at Node Red, I'm not a programmer, but elements of it seem easy enough. I understanding most programming as I use linux often, but still pretty basic. Is Node Red something that I could use in lieu of ESS to achieve my goals, and if so, is there a good community for support if I need help?
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Pv is connected to the batteries through the charge controller, so it's automatic. If you have lots of pv, consider limiting the AC in setting in the multi.
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duswami avatar image duswami kevgermany ♦♦ ·

@ejrossouw @kevgermany @kevgermany So basically I have this done. Is there a way to make AC Ignore conditional on the presence of PV only. For example, AC Ignore condition applies when PV is available, but AC Ignore conditions are 'ignored' when there's not PV.

screenshot-2022-06-20-213212.jpg

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I don't think so, sorry.
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