Multiplus 2 ess showing load on AC Output 1 when it's not connected to anything

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andy-l asked Apr 11, '24

Multiplus 2 ess showing load on AC Output 1 when it's not connected to anything

I have installed a ESS system using a multiplus 2. I have connected the inverter parallel to the grid via AC iput 1. I don't have any of the AC outputs connected.

I have a 4kw solar system on the same side as AC input 1. I measure the grid via a ET112 meter and the solar via a Victron AC Current Sensor on the temp sensor input of the mutliplus.

It's constantly showing a load on AC output 1 eventhough nothing is wired to it. The whole system shows power going to and from the grid which doesn't match what the solar is producing along with any out put from the batteries.

Can anyone point me in the right direction as to where the issue might be?

Multiplus-II ess discharging ac coupling

ess-system.jpg (10.2 KiB)

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Answer 1 · 2024-04-11T12:30:38Z

Jason - UK answered · Apr 11 at 12:30 PM

@Andy L The reason for this is the latency between the ET112 & the MPII unit. The figues provided are a calculation between the grid meter (ET112), the PV meter and the inverter / charger of the MPII unit. Due to the latency of the ET112 because of the conversion from RS485 to USB to the internal BUS of the MPII unit, you get readings that don't always add up.

There is a data sheet stating the latency of all of the approved meters & sensors. The ET112 is one of the worst performing. I also have a ET112 with the same issue of odd reading.

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andy-l commented · Apr 11 at 03:05 PM

Hi Jason

I had originally used a CT clamp, but when that was fitted it wouldn't show the load on the house when the solar was running. So I installed the ET122.

The latency still doesn't explain why the AC out of the inverter is showing as a load when nothing is wired to it

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ejrossouw andy-l commented · Apr 11 at 04:53 PM

PS - The above diagram is not correct for your setup as it actually shows critical loads and an PV inverter on the ACOUT1 That aside, ensure that grid metering is set external meter. The below example is using a CT hence the Inverter/Charger setting. Also, ensure the role for the ET112 is grid meter.

I would actually expect the following view if the system is set up and wired correctly.

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1712853392639.png (41.3 KiB)

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andy-l ejrossouw commented · Apr 12 at 10:39 AM

Here's a schematic of my setup

ESS settings

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schematic.jpg (98.8 KiB)

ess1.jpg (59.6 KiB)

ess2.jpg (53.1 KiB)

energymeter1.jpg (36.6 KiB)

energymeter2.jpg (42.9 KiB)

ejrossouw andy-l commented · Apr 12 at 11:23 AM

Looks in order. Did you install the assistant for the AC sensor? Sounds silly, but is the ET112 installed correctly with grid coming in on the left to loads on right?

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andy-l ejrossouw commented · Apr 12 at 04:28 PM

ET112 installed correctly

Here's the assistant

I have another Multiplus 2 for another customer. I think I'll do a swap to see if there is a fault in the multi as i can't figure out why its showing a load on AC out 1

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assistant1.jpg (88.1 KiB)

andy-l andy-l commented · Apr 16 at 04:25 PM

Sorted.

I put the new Multiplus 2 on today. Same wiring, same settings as I used a saved copy of the VE config file and it worked straight away.

Loads showing correctly, solar showing correctly. No load showng on AC out.

So I can only presume it was a faulty Multiplus new out of the box. I've informed my supplier who have put in a RMA request.

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