Grid-Connected Large-Scale Installation
In large-scale installations, multiple modules are connected through a junction box, which is just that. but also provides surge protection.
In order to be able to undertake repair or general maintenance work, the solar generator must be separated from the inverter. This is achieved by a DC switch close to the inverter.
As the modules continue to generate electricity as long as there is sufficient light, the DC switch must cope with the short-circuit current as well as the open-circuit voltage. Just unplugging a string of modules may cause a corona with a risk of fire. Some manufacturers of inverter offer integrated DC switches.
Inverters used here wilt most likely produce a 3-phase AC, which is more common in industrial contexts.
An optional transformer may step up the voltage to the very high voltage required by the grid.
An AC switch is required by grid operators to ensure safety. It automatically switches off the grid connection if error currents, changes in frequency, or voltage are detected.