Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 280

Advanced Operating Functions
8.17 Synchronous Transfer
Figure 8-13
Sequence of Operation
Fast bypass is disabled during pre-charge, therefore faulted cells are not reset or bypassed until
after pre-charge is complete. Only fault messages will display on the keypad or Drive Tool, there
is no message to reset the drive, but reset is required. SOP flag PrechargeNeedsReset_I
becomes true when pre-charge is in this state. The flag is reset once the drive receives a fault
reset. You can use this as an indicator that a fault exists, but do not use to directly issue a fault
reset.
1. Drive starts with pre-charge state machine set at pre-charge faulted, and all contactors are
commanded open. When all conditions are met, it passes through pre-charge initialization.
2. After initializing all contactors and flags, it advances to pre-charge ready. M1 is checked to
ensure it is open, and the state controller waits for the pre-charge start command.
3. Drive is ready to pre-charge with all conditions met. DriveReadyToPrecharge_I is true.
278
Type 5 Pre-charge Component Connections
NXGPro+ Control Manual
Operating Manual, A5E50491925A