My multiplus-ii ignores any AC input current limit I set. It only goes into “passthru“ mode when the limit is reached but otherwise draws full current from the AC input. My expectation was for “AC input current limit” to actually limit how much current is drawn from the AC input and start inverting when the limit is reached. If this is not the expected behaviour, then it’s misleading to call it such. If this is a PowerAssist only setting, why is that not made clear in the settings? Especially because it can be adjusted even when PowerAssist is turned off. I have included a screenshot showing the mpii drawing more current than the set limit. Also, I have come across a solution relating to the 3.5mm current sensor socket but my version is updated and doesn’t have that style socket.
To support the AC loads with power from the battery you need to activate PowerAssist, that’s what it is for.
Sorry to jump in. I might have misunderstood @M_Lange or @levi1234 or both. My understanding was that the OP doesn’t want to support AC loads in any way with the battery beyond the normal discharging. He just wants the inverter to disconnect from the grid when the AC in current limit is hit. Isn’t that what is supposed to happen by default? What am I missing?
Yes, I want the inverter to disconnect from grid when the AC input current limit is hit and start inverting (drawing from the batteries) and when the load goes below the limit, reconnect back to grid.
The Multiplus II manual has this to say about the current limit: “adjustable current limit for PowerControl and PowerAssist functions”
There’s also a table showing “the current limit settings for which PowerControl and PowerAssist come into operation.”. For the 5K, it says “11-100 A”.
My take:
A 1 A setting seems to be out of range. It’s not clear why lower settings are allowed, or if they’re enforced. Regardless, PowerControl limits how much power is used for charging, it can’t do more than stop charging when the limit is exceeded, i.e. it doesn’t limit what other AC loads use, just how much the MPII itself uses for charging.
With PowerAssist, the AC input isn’t disconnected when the limit is exceeded - the MPII will supplement the AC input with the inverter to the extent it can in order to stay below the limit. But again, it can’t prevent a load from drawing more than the limit plus the available inverter power.
Also, see this post.
Thank you. The limit of 1A is not out of range as the inverter goes into “passthru“ mode (charger disabled) when it’s reached. This is the behaviour with other limits as well. The linked post seems to solve the problem. However, I think Victron should rethink this setting as it is not intuitive. The manual should also be more clear about it as the person in the linked post also notes.
I had totally misunderstood how this works, so thanks @Mike.S and for the references too. It seems the only way @levi1234 can achieve what he wants is through AC ignore assistants. Otherwise, the inverter seems to be working as designed.
Hi, I’m the author of the post linked by Mike.
The solution I mentioned in that comment was the first one I developed for this problem, using the Multiplus Assistants. It’s a simpler solution and solves the problem as much as possible if you’re always going to use the same current limit on the AC input.
In my case, my installation is in an RV, so my current limit on the AC input isn’t fixed; it depends on where I am. That’s why I implemented a more complete solution that adapts to the configured current limit. This solution had to be implemented using Node-RED. In this thread, I explain everything and share the Node-RED flow I developed: Node-RED flow to set low current limit on AC input
I don’t know if currently, with the latest firmware versions, it’s possible to have a simpler solution without needing Node-RED.
Hey, thank you for this. For my setup, I have a 48v battery backup system with the multiplus-II and a smaller 12v solar system with a 375va phoenix inverter. I would like to supply the AC input of the MP-II with the output of the phoenix since my continuous loads are usually around 200 to 230 watts. I’m doing this because I want to use the 12v system in the meantime before I get solar panels for the 48v system. I think your first solution will work for me since the supply from the phoenix is fixed.
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