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Axpert - paralel PV connection


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Morning Folks,

Been scratching my head about what would be correct way to connect PV with couple of Axperts in parallel setup.

Now this sounds trivial, and probably is, but given the vagueness regarding the connection of PV in the parallel installation manual I had to ask ......

Given that the parallel installation manual describes in fine detail with supporting diagrams how to connect AC, Battery and load. But for the PV connection uses one sentence to refer the reader to the single unit installation guide, followed by a caution note that "each inverter should have their own PV cable".pic-selected-191111-0839-31.png.d5d6f373776aa8d16c6d6ab7968573f4.png

Some simple reasoning would be that typically there would be multiple strings connected via combiner box. One could take a separate cable from the combiner box to each inverter.

My questions:

How does one interpret this section of the manual?

Why the vagueness and cautionary note re PV ?

Can using combiner box as a "bus" to connect multiple inverters by their own cables be correct way ?


ManualParallel-installation-MKS-4Kva and 5kva.pdf

Edited by Padwan
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Ok, great thank you for the input.


So ill take from this that in case of multiple PV strings each inverter should have its own combiner box?

I'm kind of looking for reasoning behind this, possibly due to my ignorance about some laws of physics. But my reasoning is that splitting battery over the bus bar is similar to splitting PV arrays string via combiner box ?




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Yes, each inverter should have it's own combiner box and then 2 wires leading from that box to the inverter.

6 minutes ago, Padwan said:

splitting battery over the bus bar is similar to splitting PV arrays string via combiner box ?

Nope. The battery terminals of all the inverters are on the same potential (voltage). But the PV inputs are meant to be isolated from each other, since they are NOT on the same potential:

- Each SCC (PV input electronics) operates individually, based on the light, shades, etc.

- PV input of a typical inverter "floats", none of the input wires is grounded. Therefore, you can't share the wires between more inverters.



Couple of years ago, I was confused too, but then I found that the above wiring applies to almost any all-in-one Inverter, regardless of make and model. Contrary, when you're using a separate Solar Charger (SCC), these typically have one of their wires at the same potential with positive or negative terminal of the battery. Therefore, if that's the case, then you can use one thick wire for all such SCC's in the system. The second wire has to be individual for each SCC.

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Thank you @Youda.

This does makes sense, guessing the potential difference would cause voltage fluctuation between them and MPTT's would constantly be adjusting.... kinda like no win wars ...


oh and P.S swt setup you got. envious..

Edited by Padwan
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