question

anieuwstadt avatar image
anieuwstadt asked

Multiplus II Current values inaccurate when compared with energy meter

Hello,

System description:

  • 2 paralleled MP II 48/5000s
  • Single phase
  • ET112 energy meter
  • All loads on ACout1

The current reading of the ET112 is quite different to that of the MP II current sensor. The differences point to possibly a calibration and a scaling issue. It appears that ET112 is correct when compared to a clamp meter, which means that the MP II is most likely incorrect.

  • Blue circles are when the grid fails, and both read Zero
  • Magenta circles highlight examples of variances

The same phenomena are being seen on other systems as well, with various versions of inverter firmware. Single and 3 Phase systems, all with the MP II 48/5000

How can this be fixed?

1668495397737.png


Multiplus-IIinput current
1668495397737.png (97.8 KiB)
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1 Answer
Rob Duthie avatar image
Rob Duthie answered ·

Hi

This is expected and known, the current coils in the victron are not that accurate, as they are not a metering device were as the ET112 is a proper metering device with a high class accurate rate.

Also the clamp meter is worse, so dont expect much as per Victron documents its only a rough estimate its not a measuring METER!!! as such


Regards

Rob D

NZ

2 comments
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gnagflow avatar image gnagflow commented ·
Can’t believe that the Multiplus has a 2 Amps inaccuracy,

i compare the Victron current values regularly with bms values, and most of the time they are very similar.


who cares: everyone who want to know if the data shown could be real. I am very interested in those differences.

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anieuwstadt avatar image anieuwstadt commented ·

Hi Rob,

I have not had issues with the clamp meters that you have spoken of. In this case, the ET112 and the clamp meter are very similar.

Inaccurate measurements will have a negative bearing on the correct operation of the proportional–integral–derivative control loops inside the inverters and the Cerbo GX.

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