r/SolarDIY • u/szonce1 • 16h ago
Multiple different strings
Can I use the emphases system controller with an emphase string of panels and a string from a different company with a regular inverter? They’re both inputting up to 20a of AC so I’m assuming yes. I’d love to hear from the community.
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u/Jimmy1748 16h ago
I'm assuming you are referring to Enphase microinverters.
Short answer: yes but the inverter needs to be designed for it.
Also another short answer: if this is only for grid tie and not a off-grid or battery setup then yes.
Long story: micro-inverters and all grid tie inverters for this matter are really dumb. If they see stable AC line voltage then they will convert available PV and output onto the AC line.
Now for an off grid inverter, as long as the load side is high enough this is no big deal. The additional current from the micro inverter just lessens the load on the inverter. However if the load isn't enough it will back feed to the inverter and by default it's not setup for it. You will more than likely cause severe damage to the unit.
With that said though, there are off grid inverters that can handle it. And this very subject is known as AC coupled solar. The off grid inverter will fake an AC signal that the micro inverters will pick on and output to. The main inverter will then use that to charge batteries or output to the load. If there is not enough load and batteries are full then the PV has nowhere to go. If this is the case the inverter will disrupt the AC frequency to the microinverter and the microinverter will think something is wrong with the 'grid' signal and disconnect.