From what I've read about Enphase and other inverters, they sample the grid voltage,
then apply a slightly higher voltage. While running, they can still watch the voltage and current, keeping their output under their spec wattage.
But, they keep sampling the grid, to make sure it's still there and they are in sync etc..
When I used the 1200w GTI with the 2500w MSWI, the GTI worked, but it seemed to
be copying the waveform of the MSW.. Or, it just wasn't as strong and it's sinewave
got washed away by the stronger MSWI..
Here's some info on my backup system..
http://ecorenovator.org/forum/solar-...project-2.html