Siemens SINAMICS PERFECT HARMONY GH180 Function Manual page 307

Type 5 Pre-charge circuit design
The pre-charge circuit consists of a collection of capacitors, resistors, and contactors mounted
in the Fuse/Pre-charge/Control (FPC) cabinet on the input section of the drive.
Figure 8-19 Type 5 Pre-charge Circuit Schematic
Located on the left side is the low voltage pre-charge source coming in through the pre-charge
circuit breaker. Located on the right side is the connection to the pre-charge secondary windings
of the input transformer. Voltage during pre-charge is monitored through the input attenuators
on the primary side of the transformer. The M1 contactor connects the MV source to the primary.
The pre-charge contactors are controlled directly by the NXGpro code and require no SOP
interaction with the exception of the start pre-charge command.
Note
Precharge inductors may replace the capacitors in some special installations.
NXGPro+ Control Manual
Operating Manual, A5E50491925A
Advanced Operating Functions
8.19 Pre-charge using Dedicated I/O
305