Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 301

Cell diagnostics are not performed until precharge is complete (M1 closes and begins once the
Input voltage exceeds 60% of rated).
If all precharge conditions are met, the DriveReadyToPrecharge_I flag is true". Otherwise, the
DriveReadyToPrecharge_I flag is set false. Therefore this flag should be used as part of the
conditions to start pre-charge. Precharge cannot be initialized or started if this flag is not true.
Once precharge commences, the flag goes false and remains false until all conditions are again
met.
When all conditions are met, the pre-charge state machine advances from the initial state of
"PRECHARGE_FAULTED" through "INIT_PRECHARGE2", into the "PRECHARGE_READY" state. The
loss of the DriveReadyToPrecharge_I flag causes the state machine to cycle back to
"INIT_PRECHARGE2" until the drive is ready.
Fault and status messages will closely follow existing messages for type 5 and 6 except where
new or different.
The precharge circuit breaker is commanded to open under the following conditions during
precharge, resulting in precharge fault:
• Over-voltage (>115 %) occurs during pre-charge
• Under-Voltage Trip (PCVMRStatus_O)
• Input Protection Fault
• LFR Trip
• E-Stop (PB-4)
• M2 Contactor Open Status Failure
• Trip_CB2 is asserted (TripPrechargeCB2_O) through the SOP
The CB trip can only be controlled via the setting of an SOP flag (ClosePrechargeCB_I) to trip the
CB. To simplify, this flag will be used so that the desired action can be set to a single output point.
In addition to being triggered by an internal event, the setting of the SOP Input flag
TripPrechargeCB2_O, will also set the Output SOP flag ClosePrechargeCB_I.
Conditions to set the drive ready for precharge
The following are the conditions which set the DriveReadyToPrecharge_I flag:
• Type 4 precharge selected
• Drive not running
• MV is low (not OK)
• Output to close M1 is open, DO-14 – CIMV
• Output to M1 Permissive is open, (FPGA_M1_PERMIT) – SIB 51, 53, 55 TIMV
• M1 is open, M1 Close Ack – PrechargeM1CloseAck_I – SOP flag
• M2 is open, M2 Close Ack – PrechargeM2CloseAck_I – SOP flag
• Pre-charge circuit breaker is closed – CB2Status_O is true – SOP flag
• Pre-charge voltage monitor permissive is good – PCVMRStatus_O is true – SOP flag
• Trip precharge circuit breaker flag false - TripPrechargeCB2_O - command to trip is false - from
SOP
• No medium low fault
NXGPro+ Control Manual
Operating Manual, A5E50491925A
Advanced Operating Functions
8.19 Pre-charge using Dedicated I/O
299