Siemens SINAMICS S120 Manual page 71

Figure 2-15 Connection example Active Interface Module, frame sizes HI / JI
Same phase sequence in the precharging and main circuits
It is absolutely imperative that the precharging and main circuits have the same phase
sequence. If this is not the case, during the brief overlap period, where both contactors are
simultaneously closed, the precharging resistors will be overloaded and could be
destroyed.
Chassis power units
Manual, (GH3), 01/2013, 6SL3097-4AE00-0BP3
CAUTION
Line-side power components
2.6 Active Interface Modules
69