Hi there!,

I am doing a retrofit in an old machine. One of the Frequency inverters in the machine is the 

As the application is a constant torque and not a speed control, I guess if I need a special power modulle o CU unit for the G120 family for constant torque.

Thanks in advance.

Hello,

In order to suggest you successor/retrofit drive to your old drive, additional information is required, e.g. is drive in network? if yes which type? what is duty cycle & application? how much is loading factor? what are ambient conditions? what capacity motor is connected? does this motor system has encoder feedback etc. etc.

From the data you provided, you can check with your local Siemens service/support center suitability of G120 drive 6SL3244-0BB12-1BA1 (CU240E-2) plus 6SL3054-4AG00-2AA0 512 MB Sinamics SD card.

Hope this helps.

Constant torque in this case refers to the overload ratings of the drive and does not refer to the type of control.  There are different overload ratings for "constant torque" and "variable torque" - see attached. BUT in both cases, your drive will probably be speed controlled. if you are able to upload the configuration using Starter or DriveMonitor, you can confirm this