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AC Current sensor power too high

Hi,

I have an AC current sensor monitoring the Solar power from my inverter but the reading is always too high. The inverter is 6KW so I have configured the AC Current Sensor DIP switches to 7kW. When its full sun outside the inverted display is reporting around 6K but the remote console via the assistant is reporting around 7.4kW. This error is consistently around 20% too high, ie, at 1k of generated solar is reported at 1.2K.

I have a Multiplus II 5kW, Venus GX and ET112 energy meter. I can even see how the algorithm works, assume my export is currently 0W, batteries are fully charged, the AC sensor is reporting 2K solar generation, it does a simple calculation that I'm using what's left over - ie 2kW of AC loads in my house. But I'm actually not and I've tested this, during a sunny day my inverter reported 6kW, the AC current sensor reported 7.4KW and loads were 2.5K, I turned every MCB off and the AC loads dropped to about 2KW, I then turned the inverter off and Solar plus AC loads dropped to 0W. I can see each time the sun comes out my Solar PV on the Remote console jumps up along with my AC loads jump up.


I've tried:

Rewiring it (no change)

Moving other AC wires away from the outside of current sensing loop to avoid interference (no change)

Changing the input from AUX to Temp Sens (no change).

Changing the DIP switches to a lower power setting as the sun was setting - this reduced the level of error and DIP switch 2 seemed to be all or nothing.


I've concluded that the AC current sensor is faulty - feel free to suggest otherwise.

Based on the fiddling around I've done, I think that if the assistant's expected full power could be changed from 7.5KW to 6KW then it would solve my problem or at least make it more accurate.


Sorry this is a bit long winded leads me to the question:

Is there a way I can edit the 7.5KW value in the AC Current Sensor assistant?


Regards


Nic

Assistants
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nicd avatar image nicd commented ยท


nicd
answered ยท 0 secs ago


I've just replaced the current sensor and disappointingly the readings are still the same (way too high). So I've tired...

Changing the dip switches (when there was little solar to permit this).

Changed the wiring.

Changed the input on the multiplus

Added a variable resistor to try and attenuate the signal - which would work if it wasn't inversely proportional!

Replaced the sensor.

I've run out things I can change!

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2 Answers
kev avatar image
kev answered ยท

Hi Nic,

Iโ€™m new to this forum so forgive me if Iโ€™m talking nonsense. I donโ€™t know your system but Iโ€™m guessing you have solar panels feeding a grid tie inverter and the AC output is back feeding through your Multi to charge the batteries? I wonder if your AC current sensor is mis reading because of high frequency switching in the grid tie inverter as it produces the AC sine wave. Perhaps you could fit a mains filter to the output of your grid tie inverter.. Sorry if Iโ€™ve got it completely wrong.

Iโ€™m assuming the correct AC voltage is being monitored to calculate the AC power.

kev.

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nicd avatar image nicd commented ยท

Thank you but after 6 months I've just solved the problem, and its much simpler than you may think, I'll answer on the main thread.

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nicd avatar image
nicd answered ยท

ok I've worked it out and it's pretty simple. Unless I'm mis-interpreting the sticker on the side of the current sensor then it's wrong.

I read it as, 7kW system it shows (In My Opinion) 123-off and 4-on as I've set it in the photo. However the assistant states 123 on and 4 off, I've pasted in a screen shot showing this.

I've just changed my DIP switch settings to 123-on and 4-off as per the assistant and hey presto all sorted my readings are now correct.




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nicd avatar image nicd commented ยท

I can see it now, the white is supposed to be the DIP and the black is the gap. DOH, thats been driving me crazy for ages.

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