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Siemens SINUMERIK Controller
Program/G-code · Intermediate · 30-120 minutes
Siemens 840D 428626 - Expansion unit restoration, parameterization error, slave number
Siemens SINAMICS drive alarm 428626: Expansion unit restoration, parameterization error, slave number. This alarm indicates a fault condition in the SINAMICS servo drive system. Refer to the Siemens SINAMICS fault list documentation for the complete remedy.
428626
Siemens 840D 428626 - Expansion unit restoration, parameterization error, slave number
Expansion unit restoration, parameterization error, slave number
Siemens SINAMICS drive alarm 428626: Expansion unit restoration, parameterization error, slave number. This alarm indicates a fault condition in the SINAMICS servo drive system. Refer to the Siemens SINAMICS fault list documentation for the complete remedy.
Safety
- Refer to Siemens documentation
- Ensure qualified technician performs repairs
Common Causes
- SINAMICS drive hardware fault requiring investigation
- Drive parameter configuration error
- Axis motor or feedback system fault triggering drive protection
- Communication fault on the drive bus
- Power supply issue affecting the drive module
Troubleshooting Steps
- 1Check the SINAMICS drive for active fault codes in the diagnostics screen.
- 2Power cycle the machine to clear transient faults.
- 3Review SINAMICS parameters for the affected drive axis.
- 4Check the SINUMERIK axis diagnostics for related NC alarms.
- 5Consult the Siemens SINAMICS alarm manual for alarm 428626 complete remedy.
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Always verify with your machine manual or a certified technician before performing service procedures.