Siemens SINAMICS S120 Function Manual page 569

Winding systems for motors in SINAMICS parallel connections
The following are admissible:
● Motors with electrically isolated winding systems (multi-winding system) in which the
individual systems are not electrically coupled.
● Motors with a common winding system (single winding system) in which all parallel
windings in the motor are interconnected in such a way that from the outside they look
like a single winding system.
The following are inadmissible:
● Motors with separate winding systems on the line side which have a common, internal
neutral.
Below are two examples illustrating the possible configuration of parallel connections of
motors with a two-winding system or single winding system.
Parallel connection of two Motor Modules to one motor with double winding system
Motors in the power range from about 1 MW to 4 MW, for which power units connected in
parallel are generally used, frequently have several parallel windings. If these parallel
windings are separately routed to the terminal box of the motor, a motor is obtained with
winding systems that can be separately accessed. In this case, you can dimension a parallel
Motor Module connection so that each motor winding system is precisely supplied from one
of the Motor Modules connected in parallel. The diagram below shows this type of
arrangement.
Figure 8-26
Drive functions
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Example 1: parallel connection
Function modules
8.10 Parallel connection of power units
569