Theoretically, it is close to the MPPT maximum voltage.

It can be calculated according to the provisions in the PV power plant design code "GB50797". That is, it needs to meet the calculation according to the module open circuit voltage (the maximum number of connected modules per string) and also needs to meet the calculation according to the module operating voltage (according to the inverter MPPT efficiency). The specific decision can be made according to the actual situation.
What does the maximum DC operating current of 25/25ADV marked on the inverter mean? Does it refer to the maximum operating current of each MPPT?
The maximum input current of each MPPT is 25 A. If each MPPT with 2 strings, the maximum input current of each string is 12.5 A. If with one string, the group string current is less than 25 A

String inverters usually have more than 2 MPPTs, and each MPPT usually carries 1 or more strings. Each MPPT is independent and has tracking control for output voltage and current changes, the biggest advantage is to keep the array working at maximum output all the time, which we refer to as maximum power point tracking. Multiple directions, shadows, inconsistent string lengths, inconsistent angles, etc. are connected to different MPPTs.

1）Make sure to use locking wire terminals
2）Make sure the terminals are locked
3）Do not lock the screws on the cable insulation