What's the difference between PowerGate Plus and S-Type Satcon PVS-50 inverters?

This is the second best question of today!

The advantage of PVS-50 S Type inverter is the isolation transformer. 

The 20% boost tap on the isolation transformer increases the AC voltage output range for applications where the solar array DC operating voltage is at or near the lower end of the DC input range. This boost allows for continued inverter operation at lower DC voltage input levels.

Here are the data sheets in pdf.

• PVS-50 Powergate Plus
• PVS-50 S Type