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conkev23 avatar image
conkev23 asked

Wrong Current Readings in Multiplus II Split Phase Setup

I am getting some weird current readings for the AC in and out on my setup.screenshot-2023-07-23-133325.pngscreenshot-2023-07-23-143241.png

screenshot-2023-07-23-143335.png


The actual current readings are about 6A on L1 and L2 in and nearly zero on L1 and L2 out.

I have looked through the settings and don't see anything strange, but Multi's are configured the same way, except for the ground relay setting.

They way it is reading it is like I have the grid tied to the output on L2, but I have verified the wiring, and all is correct.

All units are on the latest firmware, except for the Cerbo GX, it's on version v3.00.


Any suggestions?

Multiplus-IIcerbo gxVRM
screenshot-2023-07-23-133325.png (80.1 KiB)
screenshot-2023-07-23-143241.png (289.4 KiB)
screenshot-2023-07-23-143335.png (292.5 KiB)
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5 Answers
conkev23 avatar image
conkev23 answered ·

ok, after isolating the L2 unit and configuring it for standalone operation, and re-verifying the grid and AC out connections, I think I have something wrong with this unit.


Is it possible AC in and AC out current sensor wires to be hooked to the wrong inputs?


I just want to add that the unit seems to do everything correctly, charge, invert, etc, either it or the Cerbo GX is reporting the current wrong.


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conkev23 avatar image
conkev23 answered ·

Ok, removed the Cerbo from the picture and went right to the Multi with the MK3.
I seems to see there is AC present on the input but reports the current on the output.


Traced out the wires to the input and they are connected to the grid and now are the only AC wires connected to the unit.


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conkev23 avatar image
conkev23 answered ·

Hi Folks,

I spent a few hours configuring each of my Multiplus II's in standalone mode, disconnecting the hardwired AC connections, testing each with the same configuration, and I have come to the conclusion that I have a defective Multiplus II. The units were charging the battery with about 5A when tested and I measured about 2.5A on the AC input wire, as stated before, the bad unit works, it just reports the AC input power in the wrong place.

He are the screen shots of the setup and console of the good Multiplus II.


1690244391367.png


1690244524340.png


And the bad Multiplus II


1690244633546.png

1690245326555.png


Time to figure out how to get a replacement from Amazon.


1690244391367.png (6.3 MiB)
1690244524340.png (294.1 KiB)
1690244633546.png (6.7 MiB)
1690245326555.png (293.3 KiB)
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sebastia avatar image
sebastia answered ·

Hi conkev23, I have the same problem with a stand alone Multiplus II where the input and output CT seems to be switched. Did you have to replace it or did you find a solution to it?

Best regards!

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conkev23 avatar image conkev23 commented ·

Hi sebastia,

I tried everything I could think of to resolve the issue but could not correct it, in the end the unit had to be replaced and all is good now.

The weird thing is that the unit worked fine just reported the current wrong.

Where did you buy your unit from?

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mjs500 avatar image
mjs500 answered ·

As your 120 ac multiplus is not for split phase just 0 -120 V AC IN at 60 Hz i may be wrong form 60 Hz you in USA and as far as i m aware USA grid runs 240 CTE system i.e.L1 120--- E ---- 120 L2 and L1 to L2 = 240v ac have just notes from your pic that older type multiplus with plug in type CT witch has been non to have problems with not making a link for internal CT

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