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beattiemark avatar image
beattiemark asked

Using CT with MultiPlus-II GX, house load not going through MultiPlus-II

Hi. I currently have a 4Kw PV with a dumb grid tied inverter installed. I now want to add Lithium batteries to store the excess PV generated electricity that is currently being exported to the grid, to use when required in order to reduce the amount of electricity I am buying from the grid. The problem I have, is due to the current house wiring and location restrictions for the batteries, I need to install the MultiPlus away from the point where the grid consumer unit and utility meter are installed. This means I can't run the MultiPulus off a meter to check the direction of flow of electricity from/to the grid, but will need to use a CT clamp on the live grid feed into the house consumer unit. Also, I can't feed the AC in through the MultiPlus before it goes into the house consumer unit. Can I just connect the batteries and the AC out, with 2 CT's (one monitoring the PV generation and the other measuring the grid usage ?

AC PV Coupling
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h-copter avatar image h-copter commented ·

Hi, I have the same problem. Please can you let me know if this works. Also, more specific details on the actual CT clamps you use. Thanks

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mondeoman answered ·

You can connect the batteries and the AC IN (not the AC out) and the two CTs.

I've seen reports of people using CTs with up to 20 meters of wire from the CT to the MultiPlus.

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beattiemark avatar image beattiemark commented ·
Thanks for the response, much appreciated. I will have another read of the manuals.
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beattiemark avatar image
beattiemark answered ·

Thanks, but how would I connect 2 CT's there appears to be only 1 connection on the MultiPlus ? Do I actually need 2 CT's, would 1 be enough just on the Utility Grid live cable coming into the house before the consumer distribution ?

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jetstram61 avatar image jetstram61 commented ·
You need the 100A 20m long current sensor for the grid, plug it into the multiplus. And for the solar you want (but don’t require for the ESS to work) the 40A current sensor. This is connected to the multi by using the aux 2 input, and requires the PV assistant to be loaded on.
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