Siemens SINAMICS V20 VFD
Siemens SINAMICS V20 VFD code A921: Analog output parameters not set properly
The analog output parameters are set to identical values, which produces illogical results and triggers a warning on the drive.
- Code
- A921
- Name
- Analog output parameters not set properly
- Controller
- Siemens SINAMICS V20 VFD
- Type
- Setup or parameter fault
- What it does
- Warning: the equipment keeps running and flags a problem
- Risk
- GREEN In your wheelhouse
- Reset
- Clears on its own when the condition goes away
- Source
- The manufacturer's manual (subscribers see which manual and page)
Updated November 4, 2026
How to fix it
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- What to do next, in plain words
- What the manual says to do, and the page it is on
- The 3 common causes listed for this code
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Questions about this code
What does Siemens SINAMICS V20 VFD code A921 mean?
The analog output parameters are set to identical values, which produces illogical results and triggers a warning on the drive.
Is Siemens SINAMICS V20 VFD code A921 dangerous?
It is graded green: in a working tech's wheelhouse with standard tools and low risk.
How do I fix Siemens SINAMICS V20 VFD code A921?
The manual's fix and the step by step check for this code are in WERCS Diagnose, plans from $49 a month. For help right now, WERCS answers 24/7 at (877) 489-3727.
Other Siemens SINAMICS V20 VFD codes
A600 · RTOS overrun warningA910 · Vdc_max controller deactivatedA911 · Vdc_max controller activeA912 · Vdc_min controller activeA922 · No load applied to converterA923 · Both JOG left and JOG right are requesteA930 · Cavitation protection warnA936 · PID autotuning activeA952 · Load monitoring warningF100 · Watchdog reset