EG4 18kPV Q+A general thread

[Markus_EG4]

The CTs need to face the inverter. You just cant get L1 CT and L2 CT mixed up. If you do it will read wrong. Not a big deal its a easy fix with settings.

 

[rmacgurn]

Thank you. Like @timselectric I do not currently have one but have been talking to James about getting one. I like to fully understand the system/support/issues before getting one which is why I've been asking questions and commenting.

Would also like to see that this updated firmware version fixes it for @rmacgurn.

Yes Rhino it is solved. in my case it seems was a two fold issue. The firmware makes a major change to how the option of self consume works. it does now what it is supposed to that is first solar/Battery then grid last. no more import and export period. only import when the solar is gone and batteries are dead or hit the SOC cutoff. as for the second error, they tell me the CT's were backwards, in a way that I do not understand. As mine face the inverter on the AC line between grid feed and inverter AC input connection as per the manual. This is of course opposite most other inverters on the market that use CT's to measure the current going back to the grid. but when I question Marcus he said that the were reversed on the L1 and L2, indication that somehow there is a difference between the two CT's. I have to admit that makes no sense to me but I looked at inverter and the reverse install check box is selected which tells me the direction of the CT's is like the rest of the world and should point to the grid connection not the inverters and the manual is wrong.

 

[Markus_EG4]

Here is the diagram.

 

[rmacgurn]

this is the typical install for CT's in solarc or solaris etc,,note it is reversed to your diagram. that is why I think you needed to do the check box to reverse the CT direction on the inverter as we have check the direction several times for past tech and flow it was installed per your diagram.

 

[Farm Boy]

Here is the diagram.

So, is this attachment correct placement of CT's?

 

[Markus_EG4]

So, is this attachment correct placement of CT's?

Yes I have 8 in R&D that way.

 

[Heritage1]

Wow this is getting confusing. Are the arrows supposed to be towards the grid or towards the inverter?
rmacgurn has them towards the inverter but with the CT direction reversed checked meaning that it should be towards the grid but the diagram from Markus (from the manual) shows them towards the inverter.

Also @Markus_SignatureSolar any update on when this new firmware will hit the app?

 

[Zapper77]

this is the typical install for CT's in solarc or solaris etc,,note it is reversed to your diagram. that is why I think you needed to do the check box to reverse the CT direction on the inverter as we have check the direction several times for past tech and flow it was installed per your diagram.
View attachment 156102

Reversed as in you may have had CT1 on red and CT2 on black. Note Black and Red aren't always the same in every community. I hear Houston is backwards.

 

[rmacgurn]

Reversed as in you may have had CT1 on red and CT2 on black. Note Black and Red aren't always the same in every community. I hear Houston is backwards.

here in Costa Rica from the meter is 3/0 all three black. we don't have colors in large sizes but sometimes white only otherwise all 2/0 up is black so I have no clue which is L1 or L2. but I think the reverse feature was for arrow direction now L1/L2 this is new to me.

 

[Zapper77]

here in Costa Rica from the meter is 3/0 all three black. we don't have colors in large sizes but sometimes white only otherwise all 2/0 up is black so I have no clue which is L1 or L2. but I think the reverse feature was for arrow direction now L1/L2 this is new to me.

Yes for CT the L1, L2 and direction matters.

 

[GuyG]

Swapping the CTs between L1 and L2 should make no difference whatsoever.

Edit: On further reflection, maybe they’ve programmed some weird distinction in there between the lines, for reasons that aren’t very apparent. In that case it might make some difference.

 

[rmacgurn]

Reversed as in you may have had CT1 on red and CT2 on black. Note Black and Red aren't always the same in every community. I hear Houston is backwards.

ok explain why that would make any difference in calculating the power feed back into the grid. its the total so both legs so if the CT for L1 is on L2 and vs version the totals are still the same unless the inverter is doing some kind of phase shifting algorithm or something odd. I understand why having the arrows going the wrong way would make a big difference as it would flip the sign on the flow of current. but not why there is a specific CT for each leg.

 

[rmacgurn]

Swapping the CTs between L1 and L2 should make no difference whatsoever.

yeah that is my option also.

 

[Markus_EG4]

yeah that is my option also.

Because L1 and L2 are 180 Degrees out of phase from each other. The inverter has grid sensing feature so whats tied to L1 needs L1 CT whats tied to L2 needs L2 CT

 

[Zapper77]

ok explain why that would make any difference in calculating the power feed back into the grid. its the total so both legs so if the CT for L1 is on L2 and vs version the totals are still the same unless the inverter is doing some kind of phase shifting algorithm or something odd. I understand why having the arrows going the wrong way would make a big difference as it would flip the sign on the flow of current. but not why there is a specific CT for each leg.

I have 14 CTs in my panel. I'm looking for supporting data that explains it better.

Until then...I can only answer with that CT1 expects to see flow in a specific form while CT2 is expects flow in the opposite. If your arrows are correct but the Legs are opposite...all you would need to do is click "reverse" CT.

 

[Farm Boy]

I would say if some one does not know which is which in the main panel, with all power off they could add the neutral to one leg testing it with a ohms meter for continuity. that would tell you if you have them on l1 or l2.

 

[JonathanW]

You’re not wrong the manual is wrong. Mine only works with the box checked backwards also

Unless all along that box is not intuitive, and has to do with l1 and l2 rather than actual direction ct meter

 

[GuyG]

I would say if some one does not know which is which in the main panel, with all power off they could add the neutral to one leg testing it with a ohms meter for continuity. that would tell you if you have them on l1 or l2.

Well, we usually think of L1 as the line coming in from the grid on the left side of the meter. I think what Markus is saying is that they define L1 not as how it comes in, but how it connects to the inverter.

 

[Quattrohead]

L1 and L2 will have different loads on the inverter output, so it needs to know what is going on on each leg. Then the sum of L1 and L2 is the total load.
Btw I have my CTs pointing to the inverter but do not have the check box checked.
So ultimately yeah the inverter needs to know which one is L1 and L2 and which way is in and out, it seems to be causing confusion so I'm sure there is work to be done to remove any doubt.
Any split phase system you have to know which is L1 and L2 otherwise your inverter could get connected 180° out of phase and that is going to cause a very large bang lol

 

[42OhmsPA]

Here is the diagram.

I don't own one but I am still considering one. The feedback for the grid is a big concern for me.
I think the diagram makes it pretty clear...
CT1 clamps around L1 from the grid / to L1 terminal on the inverter, with the arrow pointing towards the inverter. CT2 clamps around L2 from the grid / to L2 terminal on the inverter with the arrow pointing towards the inverter.
You would check the reversed CT box if you had L1 / L2 flip flopped but the arrows in the right direction.

Is that correct?
I'm not sure on the checkbox part, that may be the arrow direction, If L1 / L2 were flip flopped couldn't you just swap the CT connections at the inverter...?