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Rob Duthie avatar image
Rob Duthie asked

Multiplus 2 AC internal sensor reading high with PV inverter

Mulitplus 2 AC internal sensor reading high all the time when a PV inverter connected to AC2 output

When i plug in a external AC sensor the current is of the correct value, when no load is there it reads zero watts, But if i use the internal current sensor when no loads are there it always reads 7 to 10watts of power with the PV inverter connected it can read higher to about 20watts more.

The AC sensor is in the same place as the internal one, in the AC in All that the external ones is disconnect the internal one.

So what this does it keeps the inverter running all the time, as it see power being drawn when there is none.

I have wired the PV inverter in different place AC1 out and AC in still the same results, The internal CT has a issue, were as the external one performs as expected, No loads shows no power which you would expect.

Is it a internal calibration error?


Multiplus-II
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5 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

I presume you are using an ESS system?

7-10W sounds like the grid set point value. This is adjustable in the ESS menu.

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Rob Duthie avatar image
Rob Duthie answered ·

Hi Guy

Yes i am using ESS

My grid point is set to zero. and makes no different to the readings it can be 50 watts more higher reading. i changed that up and down to no effect.

It is the reading of the current CT of calibration?

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mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

I think that the calibration being off a few watts (5 to 7W in your case) is within what can be expected.


It’s not super accurate. For better accuracy, use an external Energy Meter.

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Rob Duthie avatar image
Rob Duthie answered ·

Hi

It is off by about 45 to 50watts, i have noticed a odd interaction with when in inverter mode it is OK, but when the grid is in parallel you notice the watts swinging all the time between these values.

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vicky avatar image
vicky answered ·

Seems the external AC Current sensors aren't precise either.
At zero load mine shows

48W - 3kW Power range, power step 17W accd. to manual

83W - 5kW Power range, power step 30W accd. to manual

As mvader stated, if acuracy is required an energy meter shall be the choice.

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