Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 297

Figure 8-18
Sequence of Operation
1. To start pre-charge, DriveReadyToPrecharge_I must be
true. PrechargeStartEnable_O is set true to start the sequence.
2. M2 is closed to connect a resistor in series with the secondary to limit in-rush to the
cells, PrechargeM2Close_I is set equal to true.
3. When the input primary voltage reaches the level set by the parameter "Precharge voltage
level" (2634), M2 is commanded to open. PrechargeM2Close_I is set equal to false.
4. The M2 acknowledge comes back, PrechargeM2CloseAck_O is set equal to true. M1
contactor is commanded to close, PrechargeM1Close_I is set equal to true.
NXGPro+ Control Manual
Operating Manual, A5E50491925A
Type 3 Pre-charge Component Connections
Advanced Operating Functions
8.18 Pre-charge using SOP
295