I’ve recently installed a a Multiplus 2 GX - 48v/5000w/70a device with a custom built 16x 280AH LiFePO4 (~14kwh) battery using an ANT BMS.
I have the grid connected to AC_IN and some of my house loads (lights and power) on AC_OUT1. Nothing is connected to AC_OUT2. All other house loads bypass the MP2GX and draw directly from the grid.
Scheduling has been setup to make use of my 0c/kwh window between 11am-2pm and this works flawlessly. The aim is to use the battery to power the house outside between 2pm and 11am.
I don’t currently have an energy meter installed (i’m waiting on an ‘RS485 to USB’ to connect my ET112), so im using the internal CT in the MP2 GX to measure voltage/current flow.
My issue is that i have a fairly constant ~100w (sometimes up to 150w) of current draw from the grid (outside of the 11am-2pm window) whilst I have a grid setpoint of 0w. Furthermore, if I change the grid setpoint to +500w, then it will import ~500w, if I change it to -500w, I still import ~100w.
This grid consumption is confirmed using a Powerpal grid meter reader which confirms that I am consuming 0.1-0.15kwh each hour from the grid.
Things I have already looked into/considered include:
*Minimum SOC (unless grid fails) set to 10% - Battery has always been above this level
*Sustain voltage set to 48V - Battery hasn’t been below 52V.
It also doesn’t seem to matter whether I’m drawing 200w or 2000w out of AC_OUT1 the grid draw remains the same.
OP if you have some of the house on ac1 out and the rest on AC in you are going to be drawing current, you would need a meter if you wanted to take the load from the AC in but I found 0 a hard target for it to consistently get so I hanged mine to -50 as I don’t want to draw any at all
Thanks for the response. I should have been more clear.
Currently the rest of the house is running directly on the grid and therefore isn’t being metered by the MP2GX. Only a couple of circuits (lights and 1 power circuit) are connected to ACOUT1.
I have the ET112 ready to roll and the MP2GX will feed the rest of the house from the ACIN, once I receive the ‘RS485 to USB’ cable, plug it in and configure it. If I can’t solve the current power draw issue, I’m hoping once I plug in the external meter (ET112) it will be solved. However, I’m not convinced that it will.
I’m in the same position as you, in terms of I’d happily feed back ~50w, as I don’t get close to using the 14kwh battery capacity on an average day. However, I can’t get it down to 0w let alone feeding back to the grid.
According your description your installation is on a single phase only, right? Is your complete house running on a single phase only? Maybe it would be helpful to provide more details about your setup.
For accurate SetPoint control I can warmly recommend meter VM-3P75CT.
@Gerd i had a similar issue in the beginning where my multiplus would not zero out the meter, apparently setting to -200 for 10 mins reconfigured it but I’m still not convinced this was the case but give it a go, but you may want to look at a thread that I posted a while back with something similar take a look and see if that’s the same issue that you are having it’s a long thread but ultimately the only way I got the issue resolved was a completely different unit that could take all the house load ie everything wired AC1 out here is the link https://communityarchive.victronenergy.com/questions/260792/warranty-not-as-good-as-whats-made-out.html
@Daza Thanks for following this up with the link, ill try and read through that thread in detail in the next few days.
@weichi Yes, the house is on single phase. The grid runs from my grid breaker into the ET112 (which is just acting as a collection point for all incoming and outgoing active cables at the moment, as there is no data cable connected to the ET112 currently). The rest of the house loads are then connected to this collection point, apart from a single power circuit (PWR1) and the lights circuit. The PWR1 and lights circuit are then connected to ACOUT1 on the MP2GX.
As i mentioned, once i get the data cable for the ET112, ill connect this and change my ‘Grid metering’ to ‘external control’ (currently set to ‘inverter/charger’) as shown in the images in the first post.
Let me know if there are other specific questions about the system
As a bit of an update, i now have the ET112 connected and set as a grid meter. It is reading grid voltage and power correctly. However, i still have the same issue where ~100w is consistenly drawn from the grid. In addition, non critical loads are also drawn from the grid, only my ACOUT1 loads are drawn from the battery.
So effectively i still have exactly the same issue, just now i can see how much power is going to the non-critical loads. Im guessing the issue is something to do with the MP2 GX not being able to send power along the ACIN line, which is why the grid needs to compensate for all loads that arent on ACOUT1. Im in Australia and have the grid set to AS/NZS 4777.2:2020 stand alone App. M (with N-bypass). I have also tried without N-bypass but this makes no difference.
Just in case someone else comes across this issue, i have found a solution after pulling my hair out for the last few weeks or so, i realised it had to be with the grid setting and so started trying different ones. Ive not got it set to the AS/NZS 4777.2 2015 (as opposed to the 2020 versions) and its all working as it should. Thanks for the responses @Daza@weichi
