Siemens G120,G120C,G130 VFD Differences

We can't easily distinguish G120, G120C and G130

Sinamics G120 is that frequency converter in which Power Module (PM) and Control Unit (CU) are separate part whereas Sinamics G120C is definitely Power Module (PM) with built-in/integrated Control Unit (CU).

Contrary, Sinamics G130 is chassis drive for built into cabinets, where everything is installed in metal frame. It consists of control unit CU320-2 and motor module. Motor module has CIM (control interface module) and 1 to 4 powerblocks. G130 CU320-2 has moreover DriveCLiQ interface for additional sensor or terminal modules.

CU models have different variant for G120.
For example -
CU model E = General purpose
CU model P = specially designed for Pump, Fan, Compressor etc
CU model S = Complex application, more precise like position tracking and other special feature. It's basically for servo application.

G120 rectifier has diode bridge. DC-link recharging is done through resistors, which are bypassed by relais after precharging is done.

G130 rectifier has thyristor bridge. Precharging is done by diode bridge and precharging resistors, conected parallel to main thyristor bridge. When DC-link working voltage level is reached, thyristors are open and drive is ready for operation.

Please refer below for details -

https://support.industry.siemens.com/...