FoxESS Community - Owners & Installers Forum

Hello,

I am totally new to solar power, so please excuse any gaps in my knowledge.

We recently had a solar installation, comprising of 24*450W panels and a KH10.5 inverter. The design schematic was for four strings, with the output spread evenly across them. Once the installers had left and I was familiarising myself with the equipment, I noticed that string three was showing 0V, whilst the others were all around 200V. I called the installers and they agreed to send the electrician back at the weekend to fix the fault.

On his return, after several failed attempts to get it working, he finally said everything was taken care off. And fair enough, the sun was out and we were getting 10KW+ of power. My only issue is that one of the strings is now disconnected, and we get two at 200V and one at 400V. I assume instead of finding the faulty wiring, he has just jumped two 'units' together. Is this OK? The inverter seems happy enough, but it bothers me that it was designed for four evenly balanced inputs, and now we have a very different configuration.

Any thoughts would be welcome.

As long as the panels on the 400V string are all facing in a similar direction/elevation, splitting them will make only a marginal difference to your performance - and the system is within it’s design specs for DC voltage and max power per MPPT.

I think the only time I would worry about the larger string being a larger string is if it had any shading, different elevations or roof directions where some of the panels could throttle the other panels, but you may also be fitted with optimisers which would reduce those effects.

Thanks for the reply.

We have got East, West, and South facing panels. I have no idea how they are configured because we have not received an updated schematic and the power output per string over the day doesn't line up neatly with how I think they might be wired.

There are optimisers fitted on the panels, so that may explain the voltage difference. Looking at the data, early morning and late evening it runs at 200V, and jumps to 400V once the sun is high enough, so I assume this is the optimisers doing their job.

Thanks for putting my mind at ease.