The image is a rough approximate of our system that I’ve inherited responsibility for. We have two equal-sized PV fields. One feeds an MPPT and outputs to a DC bus bar between the batteries and the Quattro, and the other goes to a coupled Fronius that ties into AC1 Out from the Quattro.
We’re looking to replace the dying Fronius, but I’m curious about 3 main things:
- What advantages does the Fronius have over using an MPPT and letting the Quattro do the inverting? [The only guess I have is that the power produced by the Fronius doesn’t impact the capacity of the Quattro’s output, but is that true and are their others?]
- Any advantages or disadvantages aside, is it possible and acceptable to replace a failed Fronius with an MPPT? [In the layout image, I’d replace the Fronius with another MPPT and connect the output alongside the others on the DC bus bar.]
- Any other considerations, limits, or warnings I should be aware of before attempting this (assuming it’s even do-able)?